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Al-Osaimi HM, Kanan M, Marghlani L, Al-Rowaili B, Albalawi R, Saad A, Alasmari S, Althobaiti K, Alhulaili Z, Alanzi A, Alqarni R, Alsofiyani R, Shrwani R. A systematic review on malaria and dengue vaccines for the effective management of these mosquito borne diseases: Improving public health. Hum Vaccin Immunother 2024; 20:2337985. [PMID: 38602074 PMCID: PMC11017952 DOI: 10.1080/21645515.2024.2337985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 03/28/2024] [Indexed: 04/12/2024] Open
Abstract
Insect vector-borne diseases (VBDs) pose significant global health challenges, particularly in tropical and subtropical regions. The WHO has launched the "Global Vector Control Response (GVCR) 2017-2030" to address these diseases, emphasizing a comprehensive approach to vector control. This systematic review investigates the potential of malaria and dengue vaccines in controlling mosquito-borne VBDs, aiming to alleviate disease burdens and enhance public health. Following PRISMA 2020 guidelines, the review incorporated 39 new studies out of 934 identified records. It encompasses various studies assessing malaria and dengue vaccines, emphasizing the significance of vaccination as a preventive measure. The findings indicate variations in vaccine efficacy, duration of protection, and safety considerations for each disease, influencing public health strategies. The review underscores the urgent need for vaccines to combat the increasing burden of VBDs like malaria and dengue, advocating for ongoing research and investment in vaccine development.
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Affiliation(s)
- Hind M. Al-Osaimi
- Department of Pharmacy Services Administration, King Fahad Medical City, Riyadh Second Health Cluster, Riyadh, Kingdom of Saudi Arabia
| | - Mohammed Kanan
- Department of Clinical Pharmacy, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Lujain Marghlani
- Department of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
| | - Badria Al-Rowaili
- Pharmaceutical Services Department, Northern Area Armed Forces Hospital, King Khalid Military, Hafr Al Batin, Kingdom of Saudi Arabia
| | - Reem Albalawi
- Department of Medicine, Tabuk University, Tabuk, Kingdom of Saudi Arabia
| | - Abrar Saad
- Pharmacy Department, Royal Commission Hospital, Yanbu, Kingdom of Saudi Arabia
| | - Saba Alasmari
- Department of Clinical Pharmacy, King Khalid University, Jeddah, Kingdom of Saudi Arabia
| | - Khaled Althobaiti
- Department of Medicine, Taif University, Ta’if, Kingdom of Saudi Arabia
| | - Zainab Alhulaili
- Department of Clinical Pharmacy, Dammam Medical Complex, Dammam, Kingdom of Saudi Arabia
| | - Abeer Alanzi
- Department of Medicine, King Abdulaziz Hospital, Makkah, Kingdom of Saudi Arabia
| | - Rawan Alqarni
- Department of Medicine and Surgery, King Khalid University, Abha, Kingdom of Saudi Arabia
| | - Razan Alsofiyani
- Department of Medicine, Taif University, Ta’if, Kingdom of Saudi Arabia
| | - Reem Shrwani
- Department of Clinical Pharmacy, Jazan University, Jazan, Kingdom of Saudi Arabia
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El-Moamly AA. How can we get malaria control back on track? BMJ 2024; 385:q1408. [PMID: 38925798 DOI: 10.1136/bmj.q1408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Affiliation(s)
- Amal A El-Moamly
- Department of Medical Parasitology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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Misgana T, Gebremichael B, Weldesenbet AB, Tesfaye D, Tamiru D, Tariku M, Alemu D, Dheresa M. Association between antenatal common mental disorders symptoms, and adverse obstetric and perinatal outcomes: A community-based prospective cohort study in Eastern Ethiopia. J Affect Disord 2024; 355:31-39. [PMID: 38548209 DOI: 10.1016/j.jad.2024.03.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/01/2024]
Abstract
BACKGROUND Maternal common mental disorders have broad implications for maternal and child mental and physical health that may have a long-lasting social and economic impact. This study aimed to assess the association between symptoms of antenatal common mental disorders and obstetric and perinatal outcomes in Eastern Ethiopia. METHODS A community-based prospective cohort study was conducted and a total of 1011 randomly selected pregnant women were followed up from February 1, 2021, to January 30, 2022. The modified Poisson regression model with a robust variance was fitted to examine the effect of the symptoms of antenatal common mental disorders on obstetric and perinatal outcomes. RESULTS Antenatal common mental disorders (SRQ ≥ 6) were presented among 390 (38.58 %) pregnant women. In the final multivariate Poisson regression model, women with antenatal common mental disorders symptoms had an increased risk of some pregnancy complications (ARR = 1.65, 95 % CI: 1.59, 1.84). In the current study, symptoms of antenatal common mental disorders increased also the risk of preterm birth (ARR = 1.71; 95 % CI: 1.20, 2.42) and low birth weight (ARR = 1.93; 95 % CI: 1.36, 2.74). LIMITATION The indirect effects of some potential mediators and moderators were not assessed in this study. CONCLUSION The study found a high rate of symptoms of antenatal common mental disorders and adverse obstetric and perinatal outcomes. Antenatal common mental disorders symptoms may have considerable effects on individual and combined pregnancy complications and adverse perinatal outcomes.
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Affiliation(s)
- Tadesse Misgana
- Department of Psychiatry, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia.
| | - Berhe Gebremichael
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Adisu Birhanu Weldesenbet
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Dejene Tesfaye
- Department of Psychiatry, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Dawit Tamiru
- Department of Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Mandaras Tariku
- Department of Psychiatry, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Daniel Alemu
- Department of Psychiatry, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Merga Dheresa
- School of Nursing and Midwifery, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
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Lyimo BM, Bakari C, Popkin-Hall ZR, Giesbrecht DJ, Seth MD, Pereus D, Shabani ZI, Moshi R, Boniface R, Mandara CI, Madebe R, Juliano JJ, Bailey JA, Ishengoma DS. Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity. Malar J 2024; 23:139. [PMID: 38720288 PMCID: PMC11080125 DOI: 10.1186/s12936-024-04974-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND In 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (PfCSP), but polymorphisms in the gene raise concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission intensities in Mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. METHODS The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of Mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright's inbreeding coefficient (Fws), Wright's fixation index (FST), principal component analysis, nucleotide diversity, and Tajima's D were used to assess within-host parasite diversity, population structure and natural selection. RESULTS Based on Fws (< 0.95), there was high polyclonality (ranging from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST = 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima's D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences revealed 50 different haplotypes (H_1 to H_50), with only 2% of sequences matching the 3D7 strain haplotype (H_50). Conversely, with the NF54 strain, the Pfcsp C-terminal sequences revealed 49 different haplotypes (H_1 to H_49), with only 0.4% of the sequences matching the NF54 strain (Hap_49). CONCLUSIONS The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima's D values, consistent with balancing selection for variants within Th2R and Th3R regions. The study observed differences between the intended haplotypes incorporated into the design of RTS,S and R21 vaccines and those present in natural parasite populations. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.
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Affiliation(s)
- Beatus M Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania.
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Misago D Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Zulfa I Shabani
- Dar Es Salaam University College of Education, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth Boniface
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Celine I Mandara
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Rashid Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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5
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Lyimo BM, Bakari C, Popkin-Hall ZR, Giesbrecht DJ, Seth MD, Pereus D, Moshi R, Boniface R, Mandara CI, Madebe R, Juliano JJ, Bailey JA, Ishengoma DS. Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.23.24301587. [PMID: 38343796 PMCID: PMC10854334 DOI: 10.1101/2024.01.23.24301587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Background In 2021 and 2023, the World Health Organization approved RTS, S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (Pfcsp) but polymorphisms in this gene raises concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission in mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. Methods The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright's inbreeding coefficient (Fws), Wright's fixation index (FST), principal component analysis, nucleotide diversity, and Tajima's D were used to assess within-host parasite diversity, population structure and natural selection. Results Based on Fws (< 0.95), there was high polyclonality (ranged from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST= 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima's D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences had 50 different haplotypes (H_1 to H_50) and only 2% of sequences matched the 3D7 strain haplotype (H_50). Conclusions The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima's D values for parasite populations, consistent with balancing selection for variants within Th2R and Th3R regions. This data is consistent with other studies conducted across Africa and worldwide, which demonstrate low 3D7 haplotypes and little population structure. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.
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Affiliation(s)
- Beatus M. Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Misago D. Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth Boniface
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | | | - Rashid Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Deus S. Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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Abo YN, Jamrozik E, McCarthy JS, Roestenberg M, Steer AC, Osowicki J. Strategic and scientific contributions of human challenge trials for vaccine development: facts versus fantasy. THE LANCET. INFECTIOUS DISEASES 2023; 23:e533-e546. [PMID: 37573871 DOI: 10.1016/s1473-3099(23)00294-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 08/15/2023]
Abstract
The unprecedented speed of delivery of SARS-CoV-2 pandemic vaccines has redefined the limits for all vaccine development. Beyond the aspirational 100-day timeline for tomorrow's hypothetical pandemic vaccines, there is a sense of optimism that development of other high priority vaccines can be accelerated. Early in the COVID-19 pandemic, an intense and polarised academic and public discourse arose concerning the role of human challenge trials for vaccine development. A case was made for human challenge trials as a powerful tool to establish early proof-of-concept of vaccine efficacy in humans, inform vaccine down selection, and address crucial knowledge gaps regarding transmission, pathogenesis, and immune protection. We review the track record of human challenge trials contributing to the development of vaccines for 19 different pathogens and discuss relevant limitations, barriers, and pitfalls. This Review also highlights opportunities for efforts to broaden the scope and boost the effects of human challenge trials, to accelerate all vaccine development.
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Affiliation(s)
- Yara-Natalie Abo
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia.
| | - Euzebiusz Jamrozik
- Ethox and Pandemic Sciences Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK; Monash-WHO Collaborating Centre for Bioethics, Monash University, Melbourne, VIC, Australia
| | - James S McCarthy
- Department of Infectious Diseases, The University of Melbourne, Parkville, VIC, Australia; Victorian Infectious Diseases Services, Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Meta Roestenberg
- Controlled Human Infections Center, Leiden University Medical Center, Leiden, Netherlands
| | - Andrew C Steer
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia
| | - Joshua Osowicki
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia
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Abstract
Malaria is a mosquito-borne disease caused by protozoan parasites of the genus Plasmodium. Despite significant declines in malaria-attributable morbidity and mortality over the last two decades, it remains a major public health burden in many countries. This underscores the critical need for improved strategies to prevent, treat and control malaria if we are to ultimately progress towards the eradication of this disease. Ideally, this will include the development and deployment of a highly effective malaria vaccine that is able to induce long-lasting protective immunity. There are many malaria vaccine candidates in development, with more than a dozen of these in clinical development. RTS,S/AS01 (also known as Mosquirix) is the most advanced malaria vaccine and was shown to have modest efficacy against clinical malaria in phase III trials in 5- to 17-month-old infants. Following pilot implementation trials, the World Health Organisation has recommended it for use in Africa in young children who are most at risk of infection with P. falciparum, the deadliest of the human malaria parasites. It is well recognised that more effective malaria vaccines are needed. In this review, we discuss malaria vaccine candidates that have progressed into clinical evaluation and highlight the most advanced candidates: Sanaria's irradiated sporozoite vaccine (PfSPZ Vaccine), the chemoattenuated sporozoite vaccine (PfSPZ-CVac), RTS,S/AS01 and the novel malaria vaccine candidate, R21, which displayed promising, high-level efficacy in a recent small phase IIb trial in Africa.
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Affiliation(s)
- Danielle I Stanisic
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia.
| | - Michael F Good
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, Australia.
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Alonso A, Alcolea PJ, Larraga J, Peris MP, Esteban A, Cortés A, Ruiz-García S, Castillo JA, Larraga V. A non-replicative antibiotic resistance-free DNA vaccine delivered by the intranasal route protects against canine leishmaniasis. Front Immunol 2023; 14:1213193. [PMID: 37790927 PMCID: PMC10543895 DOI: 10.3389/fimmu.2023.1213193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/11/2023] [Indexed: 10/05/2023] Open
Abstract
Leishmania infantum is the etiological agent of zoonotic visceral leishmaniasis (ZVL). The disease is endemic in Central and South America, Central and South East Asia, and the Mediterranean basin. Dogs are the main reservoir, with an estimated prevalence of approximately 2.5 million dogs in Southern Europe. Current treatments cause side effects, disease recurrence, and drug resistance. Therefore, the development of vaccines against canine leishmaniasis is necessary. We have generated a DNA vaccine based on the non-replicative antibiotic resistance marker-free plasmid vector pPAL that contains the encoding gene for the L. infantum activated protein kinase C receptor analog (LACK). Homologous pPAL-LACK prime-boost intranasal administration confers efficacious protection in Beagle dogs with a reduction of clinical signs and a statistically significant reduction of the parasite burden in the bone marrow of more than 90% of dogs after experimental infection with highly infective promastigotes. This DNA vaccine elicits a robust cellular immune response skewed towards the Th1 profile.
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Affiliation(s)
- Ana Alonso
- Laboratory of Molecular Parasitology and Vaccines, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIBMS-CSIC), Madrid, Spain
| | - Pedro José Alcolea
- Laboratory of Molecular Parasitology and Vaccines, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIBMS-CSIC), Madrid, Spain
| | - Jaime Larraga
- Laboratory of Molecular Parasitology and Vaccines, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIBMS-CSIC), Madrid, Spain
| | - María Paz Peris
- Laboratory of Parasitology, Department of Animal Pathology, Faculty of Veterinary Science, University of Zaragoza, Zaragoza, Spain
| | - Adriana Esteban
- Laboratory of Parasitology, Department of Animal Pathology, Faculty of Veterinary Science, University of Zaragoza, Zaragoza, Spain
| | - Alberto Cortés
- Laboratory of Parasitology, Department of Animal Pathology, Faculty of Veterinary Science, University of Zaragoza, Zaragoza, Spain
| | - Silvia Ruiz-García
- Laboratory of Molecular Parasitology and Vaccines, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIBMS-CSIC), Madrid, Spain
| | - Juan Antonio Castillo
- Laboratory of Parasitology, Department of Animal Pathology, Faculty of Veterinary Science, University of Zaragoza, Zaragoza, Spain
| | - Vicente Larraga
- Laboratory of Molecular Parasitology and Vaccines, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CIBMS-CSIC), Madrid, Spain
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El-Moamly AA, El-Sweify MA. Malaria vaccines: the 60-year journey of hope and final success-lessons learned and future prospects. Trop Med Health 2023; 51:29. [PMID: 37198702 DOI: 10.1186/s41182-023-00516-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/18/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND The world has made great strides towards beating malaria, although about half of the world population is still exposed to the risk of contracting malaria. Developing an effective malaria vaccine was a huge challenge for medical science. In 2021 the World Health Organization (WHO) approved the first malaria vaccine, RTS,S/AS01 vaccine (Mosquirix™), for widespread use. This review highlights the history of development, and the different approaches and types of malaria vaccines, and the literature to date. It covers the developmental stages of RTS,S/AS01 and recommends steps for its deployment. The review explores other potential vaccine candidates and their status, and suggests options for their further development. It also recommends future roles for vaccines in eradicating malaria. Questions remain on how RTS,S vaccine will work in widespread use and how it can best be utilized to benefit vulnerable communities. CONCLUSION Malaria vaccines have been in development for almost 60 years. The RTS,S/AS01 vaccine has now been approved, but cannot be a stand-alone solution. Development should continue on promising candidates such as R21, PfSPZ and P. vivax vaccines. Multi-component vaccines may be a useful addition to other malaria control techniques in achieving eradication of malaria.
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Affiliation(s)
- Amal A El-Moamly
- Department of Medical Parasitology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
| | - Mohamed A El-Sweify
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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Emanuel EJ, Persad G. The shared ethical framework to allocate scarce medical resources: a lesson from COVID-19. Lancet 2023:S0140-6736(23)00812-7. [PMID: 37172603 PMCID: PMC10168660 DOI: 10.1016/s0140-6736(23)00812-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 05/15/2023]
Abstract
The COVID-19 pandemic has helped to clarify the fair and equitable allocation of scarce medical resources, both within and among countries. The ethical allocation of such resources entails a three-step process: (1) elucidating the fundamental ethical values for allocation, (2) using these values to delineate priority tiers for scarce resources, and (3) implementing the prioritisation to faithfully realise the fundamental values. Myriad reports and assessments have elucidated five core substantive values for ethical allocation: maximising benefits and minimising harms, mitigating unfair disadvantage, equal moral concern, reciprocity, and instrumental value. These values are universal. None of the values are sufficient alone, and their relative weight and application will vary by context. In addition, there are procedural principles such as transparency, engagement, and evidence-responsiveness. Prioritising instrumental value and minimising harms during the COVID-19 pandemic led to widespread agreement on priority tiers to include health-care workers, first responders, people living in congregate housing, and people with an increased risk of death, such as older adults and individuals with medical conditions. However, the pandemic also revealed problems with the implementation of these values and priority tiers, such as allocation on the basis of population rather than COVID-19 burden, and passive allocation that exacerbated disparities by requiring recipients to spend time booking and travelling to appointments. This ethical framework should be the starting point for the allocation of scarce medical resources in future pandemics and other public health conditions. For instance, allocation of the new malaria vaccine among sub-Saharan African countries should be based not on reciprocity to countries that participated in research, but on maximally reducing serious illness and deaths, especially among infants and children.
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Affiliation(s)
- Ezekiel J Emanuel
- Healthcare Transformation Institute, Department of Medical Ethics & Health Policy, Perelman School of Medicine and Wharton School, University of Pennsylvania, Philadelphia, PA, USA.
| | - Govind Persad
- Sturm College of Law, University of Denver, Denver, CO, USA
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11
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Mariano RMDS, Gonçalves AAM, de Oliveira DS, Ribeiro HS, Pereira DFS, Santos IS, Lair DF, da Silva AV, Galdino AS, Chávez-Fumagalli MA, da Silveira-Lemos D, Dutra WO, Giunchetti RC. A Review of Major Patents on Potential Malaria Vaccine Targets. Pathogens 2023; 12:pathogens12020247. [PMID: 36839519 PMCID: PMC9959516 DOI: 10.3390/pathogens12020247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Malaria is a parasitic infection that is a great public health concern and is responsible for high mortality rates worldwide. Different strategies have been employed to improve disease control, demonstrating the ineffectiveness of controlling vectors, and parasite resistance to antimalarial drugs requires the development of an effective preventive vaccine. There are countless challenges to the development of such a vaccine directly related to the parasite's complex life cycle. After more than four decades of basic research and clinical trials, the World Health Organization (WHO) has recommended the pre-erythrocytic Plasmodium falciparum (RTS, S) malaria vaccine for widespread use among children living in malaria-endemic areas. However, there is a consensus that major improvements are needed to develop a vaccine with a greater epidemiological impact in endemic areas. This review discusses novel strategies for malaria vaccine design taking the target stages within the parasite cycle into account. The design of the multi-component vaccine shows considerable potential, especially as it involves transmission-blocking vaccines (TBVs) that eliminate the parasite's replication towards sporozoite stage parasites during a blood meal of female anopheline mosquitoes. Significant improvements have been made but additional efforts to achieve an efficient vaccine are required to improve control measures. Different strategies have been employed, thus demonstrating the ineffectiveness in controlling vectors, and parasite resistance to antimalarial drugs requires the development of a preventive vaccine. Despite having a vaccine in an advanced stage of development, such as the RTS, S malaria vaccine, the search for an effective vaccine against malaria is far from over. This review discusses novel strategies for malaria vaccine design taking into account the target stages within the parasite's life cycle.
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Affiliation(s)
- Reysla Maria da Silveira Mariano
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Ana Alice Maia Gonçalves
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Diana Souza de Oliveira
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Helen Silva Ribeiro
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Diogo Fonseca Soares Pereira
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Ingrid Soares Santos
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Daniel Ferreira Lair
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Augusto Ventura da Silva
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Alexsandro Sobreira Galdino
- Laboratory of Biotechnology of Microorganisms, Federal University of São João Del-Rei, Divinópolis CEP 35501-296, MG, Brazil
| | - Miguel Angel Chávez-Fumagalli
- Computational Biology and Chemistry Research Group, Vicerrectorado de Investigación, Universidad Católica de Santa María, Urb. San José S/N, Arequipa 04000, Peru
| | - Denise da Silveira-Lemos
- Campus Jaraguá, University José of Rosário Vellano, UNIFENAS, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Walderez Ornelas Dutra
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
| | - Rodolfo Cordeiro Giunchetti
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CEP 31270-901, MG, Brazil
- Correspondence: or ; Tel.: +55-31-3409-3003
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He ZQ, Zhang QQ, Wang D, Hu YB, Zhou RM, Qian D, Yang CY, Lu DL, Li SH, Liu Y, Zhang HW. Genetic polymorphism of circumsporozoite protein of Plasmodium falciparum among Chinese migrant workers returning from Africa to Henan Province. Malar J 2022; 21:248. [PMID: 36030242 PMCID: PMC9419638 DOI: 10.1186/s12936-022-04275-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 08/18/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium falciparum malaria is recognized as a major global public health problem. The malaria vaccine was important because the case fatality rate of falciparum malaria was high. Plasmodium falciparum circumsporozoite protein (PfCSP) is one of the potential vaccine candidates, but the genetic polymorphism of PfCSP raises concerns regarding the efficacy of the vaccine. This study aimed to investigate the genetic polymorphism of PfCSP and provide data for the improvement of PfCSP-based vaccine (RTS,S malaria vaccine). METHODS Blood samples were collected from 287 Chinese migrant workers who were infected with P. falciparum and returning from Africa to Henan Province during 2016-2018. The Pfcsp genes were analysed to estimate the genetic diversity of this parasite. RESULTS The results showed that there were two mutations at the N-terminus of imported Pfcsp in Henan Province, including insertion amino acids (58.71%, 118/201) and A → G (38.81%, 78/201). The number of repeats of tetrapeptide motifs (NANP/NVDP/NPNP/NVDA) in the central repeat region ranged mainly from 39 to 42 (97.51%, 196/201). A total of 14 nonsynonymous amino acid changes were found at the C-terminus. The average nucleotide difference (K) of imported Pfcsp in Henan Province was 5.719, and the haplotype diversity (Hd) was 0.964 ± 0.004. The estimated value of dN-dS was 0.047, indicating that the region may be affected by positive natural selection. The minimum number of recombination events (Rm) of imported Pfcsp in Henan Province was close to that in Africa. The analysis of genetic differentiation showed that there may be moderate differentiation between East Africa and North Africa (Fst = 0.06484), and the levels of differentiation in the other regions were very small (Fst < 0.05). CONCLUSIONS The N-terminus of Pfcsp was relatively conserved, and the central repeat region and the Th2R and Th3R regions of the C-terminus were highly polymorphic. The gene polymorphism pattern among Chinese migrant workers returning from Africa to Henan Province was consistent with that in Africa. The geographical pattern of population differentiation and the evidence of natural selection and gene recombination suggested that the effect of polymorphism on the efficacy of PfCSP-based vaccines should be considered.
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Affiliation(s)
- Zhi-Quan He
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - Qun-Qun Zhang
- Fengtai District Center for Disease Control and Prevention, Beijing, China
| | - Dan Wang
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - Ya-Bo Hu
- College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Rui-Min Zhou
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - Dan Qian
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - Cheng-Yun Yang
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - De-Ling Lu
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - Su-Hua Li
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China.,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China
| | - Ying Liu
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China. .,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China.
| | - Hong-Wei Zhang
- Department of Parasite Disease Control and Prevention, Henan Center for Disease Control and Prevention, Zhengzhou, China. .,Henan Key Laboratory of Pathogenic Microorganisms, No. 105 South Agricultural Road, Zhengdong New District, Zhengzhou, 450016, China.
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Mohamed NS, AbdElbagi H, Elsadig AR, Ahmed AE, Mohammed YO, Elssir LT, Elnour MAB, Ali Y, Ali MS, Altahir O, Abubakr M, Siddig EE, Ahmed A, Omer RA. Assessment of genetic diversity of Plasmodium falciparum circumsporozoite protein in Sudan: the RTS,S leading malaria vaccine candidate. Malar J 2021; 20:436. [PMID: 34758827 PMCID: PMC8579544 DOI: 10.1186/s12936-021-03971-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 11/01/2021] [Indexed: 11/20/2022] Open
Abstract
Background The currently used malaria vaccine, RTS,S, is designed based on the Plasmodium falciparum circumsporozoite protein (PfCSP). The pfcsp gene, besides having different polymorphic patterns, can vary between P. falciparum isolates due to geographical origin and host immune response. Such aspects are essential when considering the deployment of the RTS,S vaccine in a certain region. Therefore, this study assessed the genetic diversity of P. falciparum in Sudan based on the pfcsp gene by investigating the diversity at the N-terminal, central repeat, and the C-terminal regions. Methods A cross-sectional molecular study was conducted; P. falciparum isolates were collected from different health centres in Khartoum State between January and December 2019. During the study period, a total of 261 febrile patients were recruited. Malaria diagnosis was made by expert microscopists using Giemsa-stained thick and thin blood films. DNA samples were examined by the semi-nested polymerase chain reaction (PCR). Single clonal infection of the confirmed P. falciparum cases, were used to amplify the pfcsp gene. The amplified amplicons of pfcsp have been sequenced using the Sanger dideoxy method. The obtained sequences of pfcsp nucleotide diversity parameters including the numbers of haplotypes (Hap), haplotypes diversity (Hapd), the average number of nucleotide differences between two sequences (p), and the numbers of segregating sites (S) were obtained. The haplotype networks were constructed using the online tcsBU software. Natural selection theory was also tested on pfcsp using Fuand Li’s D, Fuand Li’s F statistics, and Tajima’s D test using DnaSP. Results In comparison with the different pfcsp reference strains, the Sudanese isolates showed high similarity with other African isolates. The results of the N-terminal region showed the presence of 2 different haplotypes with a Hapd of 0.425 ± 0.00727. The presence of the unique insertion of NNNGDNGREGKDEDKRDGNN was reported. The KLKQP motif was conserved in all the studied isolates. At the central repeat region, 11 haplotypes were seen with a Hapd of 0.779 ± 0.00097. The analysis of the genetic diversity in the C-terminal region showed the presence of 10 haplotypes with a Hapd of 0.457 ± 0.073. Several non-synonymous amino acids changes were also seen at the Th2R and the Th3R T-cell epitope regions including T317K, E317K, Q318E, K321N, I322K, T322K, R322K, K324Q, I327L, G352N, S354P, R355K, N356D, Q357E, and E361A. Conclusions In this study, the results indicated a high conservation at the pfcsp gene. This may further contribute in understanding the genetic polymorphisms of P. falciparum prior to the deployment of the RTS,S vaccine in Sudan.
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Affiliation(s)
- Nouh Saad Mohamed
- Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan. .,Molecular Biology Unit, Sirius Training and Research Centre, Khartoum, Sudan.
| | - Hanadi AbdElbagi
- Molecular Biology Unit, Sirius Training and Research Centre, Khartoum, Sudan
| | | | | | - Yassir Osman Mohammed
- Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Lubna Taj Elssir
- Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Mohammed-Ahmed B Elnour
- Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Yousif Ali
- Health Emergencies and Epidemics Control General Directorate, Sudan Federal Ministry of Health, Khartoum, Sudan
| | - Mohamed S Ali
- Faculty of Medicine, EL-Neelain University, Khartoum, Sudan
| | - Omnia Altahir
- Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
| | - Mustafa Abubakr
- Department of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum, Sudan
| | | | - Ayman Ahmed
- Molecular Biology Unit, Sirius Training and Research Centre, Khartoum, Sudan
| | - Rihab Ali Omer
- Pediatric Epidemiology, Clinic and Polyclinic for Child and Adolescent Medicine, Medical Faculty, University of Leipzig, Leipzig, Germany
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Pirahmadi S, Zakeri S, Djadid ND, Mehrizi AA. A review of combination adjuvants for malaria vaccines: a promising approach for vaccine development. Int J Parasitol 2021; 51:699-717. [PMID: 33798560 DOI: 10.1016/j.ijpara.2021.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 12/18/2020] [Accepted: 01/28/2021] [Indexed: 01/16/2023]
Abstract
It is obvious that there is a critical need for an efficient malaria vaccine to accelerate malaria eradication. Currently, recombinant subunit vaccination against malaria using proteins and peptides is gaining attention. However, one of the major drawbacks of this approach is the lack of an efficient and durable immune response. Therefore, subunit vaccines require adjuvants to make the vaccine sufficiently immunogenic. Considering the history of the RTS,S vaccine, it seems likely that no single adjuvant is capable of eliciting all the protective immune responses required in many malarial subunit vaccines and the use of combination adjuvants will be increasingly important as the science of malaria vaccines advances. In light of this, it appears that identifying the most effective mixture of adjuvants with minimal adverse effects offers tremendous opportunities in improving the efficacy of vaccines against malaria. Owing to the importance of a multi-adjuvanted approach in subunit malaria vaccine development, this review paper outlines some of the best known combination adjuvants used in malaria subunit vaccines, focusing on their proposed mechanisms of action, their immunological properties, and their notable results. The aim of the present review is to consolidate these findings to aid the application of these combination adjuvants in experimental malaria vaccines.
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Affiliation(s)
- Sakineh Pirahmadi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Navid D Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Akram A Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
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Berrueta M, Ciapponi A, Bardach A, Cairoli FR, Castellano FJ, Xiong X, Stergachis A, Zaraa S, Meulen AST, Buekens P. Maternal and neonatal data collection systems in low- and middle-income countries for maternal vaccines active safety surveillance systems: A scoping review. BMC Pregnancy Childbirth 2021; 21:217. [PMID: 33731029 PMCID: PMC7968860 DOI: 10.1186/s12884-021-03686-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/01/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Most post-licensure vaccine pharmacovigilance in low- and middle-income countries (LMICs) are passive reporting systems. These have limited utility for maternal immunization pharmacovigilance in LMIC settings and need to be supplemented with active surveillance. Our study's main objective was to identify existing perinatal data collection systems in LMICs that collect individual information on maternal and neonatal health outcomes and could be developed to inform active safety surveillance of novel vaccines for use during pregnancy. METHODS A scoping review was performed following the Arksey and O'Malley six-stage approach. We included studies describing electronic or mixed paper-electronic data collection systems in LMICs, including research networks, electronic medical records, and custom software platforms for health information systems. Medline PubMed, EMBASE, Global Health, Cochrane Library, LILACS, Bibliography of Asian Studies (BAS), and CINAHL were searched through August 2019. We also searched grey literature including through Google and websites of existing relevant perinatal data collection systems, as well as contacted authors of key studies and experts in the field to validate the information and identify additional sources of relevant unpublished information. RESULTS A total of 11,817 records were identified. The full texts of 264 records describing 96 data collection systems were assessed for eligibility. Eight perinatal data collection systems met our inclusion criteria: Global Network's Maternal Newborn Health Registry, International Network for the Demographic Evaluation of Populations and their Health; Perinatal Informatic System; Pregnancy Exposure Registry & Birth Defects Surveillance; SmartCare; Open Medical Record System; Open Smart Register Platform and District Health Information Software 2. These selected systems were qualitatively characterized according to seven different domains: governance; system design; system management; data management; data sources, outcomes and data quality. CONCLUSION This review provides a list of active maternal and neonatal data collection systems in LMICs and their characteristics as well as their outreach, strengths, and limitations. Findings could potentially help further understand where to obtain population-based high-quality information on outcomes to inform the conduct of maternal immunization active vaccine safety surveillance activities and research in LMICs.
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Affiliation(s)
- Mabel Berrueta
- Instituto de Efectividad Clínica y Sanitaria (IECS), Dr. Emilio Ravignani 2024 (C1014CPV), Buenos Aires, Argentina.
| | - Agustin Ciapponi
- Instituto de Efectividad Clínica y Sanitaria (IECS), Dr. Emilio Ravignani 2024 (C1014CPV), Buenos Aires, Argentina
| | - Ariel Bardach
- Instituto de Efectividad Clínica y Sanitaria (IECS), Dr. Emilio Ravignani 2024 (C1014CPV), Buenos Aires, Argentina
| | - Federico Rodriguez Cairoli
- Instituto de Efectividad Clínica y Sanitaria (IECS), Dr. Emilio Ravignani 2024 (C1014CPV), Buenos Aires, Argentina
| | - Fabricio J Castellano
- Instituto de Efectividad Clínica y Sanitaria (IECS), Dr. Emilio Ravignani 2024 (C1014CPV), Buenos Aires, Argentina
| | - Xu Xiong
- Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 70112, USA
| | | | - Sabra Zaraa
- University of Washington, Seattle, WA, 98195-7631, USA
| | | | - Pierre Buekens
- Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 70112, USA
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Arora N, C Anbalagan L, Pannu AK. Towards Eradication of Malaria: Is the WHO's RTS,S/AS01 Vaccination Effective Enough? Risk Manag Healthc Policy 2021; 14:1033-1039. [PMID: 33737844 PMCID: PMC7966294 DOI: 10.2147/rmhp.s219294] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/26/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Recent advances in mosquito eradication and antimalarial treatments have reduced the malaria burden only modestly. An effective malaria vaccine remains a high priority, but its development has several challenges. Among many potential candidates, the RTS,S/AS01 vaccine (MosquirixTM) remains the leading candidate. OBJECTIVE AND METHOD This review aims to understand the advances in the RTS,S/AS01 vaccine, and future comments regarding the vaccine's effectiveness in malaria eradication. Literature review for the past five decades was performed searching PubMed, EMBASE Ovid, and Cochrane Library, with using the following search items: ("malaria" OR "WHO's malaria" OR "Plasmodium falciparum" OR "RTS,S" OR "RTS,S/AS01" OR "RTS,S/AS02" OR "pre-erythrocytic malaria" OR "circumsporozoite" OR "Mosquirix") AND ("vaccine" OR "vaccination"). RESULTS RTS,S/AS01, a recombinant pre-erythrocytic vaccine containing Plasmodium falciparum surface-protein (circumsporozoite) antigen, is safe, well-tolerated, and immunogenic in children. Three doses, along with a booster, have a modest efficacy of about 36% in children (age 5-17 months) and about 26% in infants (age 6-12 weeks) against clinical malaria during a 48-month follow-up. However, the efficacy varies among population subgroups and with the parasite strain, it reduces without a booster and offers protection for a limited duration. Because of its potential cost-effectiveness and positive public health effect, the vaccine is being investigated in a pilot program for mortality benefits and broader deployment. CONCLUSION The RTS,S/AS01 vaccine prevents malaria; however, it should be considered another addition to the malaria-control program and not as an eradication tool because of its relatively low to modest efficacy.
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Affiliation(s)
- Navneet Arora
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | - Ashok K Pannu
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Chatterjee D, Cockburn IA. The challenges of a circumsporozoite protein-based malaria vaccine. Expert Rev Vaccines 2021; 20:113-125. [PMID: 33554669 DOI: 10.1080/14760584.2021.1874924] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION A safe and effective vaccine will likely be necessary for the control or eradication of malaria which kills 400,000 annually. Our most advanced vaccine candidate to date is RTS,S which is based on the Plasmodium falciparum circumsporozoite protein (PfCSP) of the malaria parasite. However, protection by RTS,S is incomplete and short-lived. AREAS COVERED Here we summarize results from recent clinical trials of RTS,S and critically evaluate recent studies that aim to understand the correlates of protective immunity and why vaccine-induced protection is short-lived. In particular, recent systems serology studies have highlighted a key role for the necessity of inducing functional antibodies. In-depth analyses of immune responses to CSP in both mouse models and vaccinated humans have also highlighted difficulties in generating the maintaining high-quality antibody responses. Finally, in recent years biophysical and structural studies of antibody binding to PfCSP have led to a better understanding of how highly potent antibodies can block infection, which can inform vaccine design. EXPERT OPINION We highlight how both structure-guided vaccine design and a better understanding of the immune response to PfCSP can inform a second generation of PfCSP-based vaccines stimulating a broader range of protective targets within PfCSP.
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Affiliation(s)
- Deepyan Chatterjee
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, the Australian National University, Canberra, Australia
| | - Ian Andrew Cockburn
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, the Australian National University, Canberra, Australia
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Brunetti G, Padovani F, De Pastina A, Rotella C, Monahan A, Hoffman SL, Jongo SA, Abdulla S, Corradin G, Pluschke G, Daubenberger C, Hegner M. Nanotechnological immunoassay for rapid label-free analysis of candidate malaria vaccines. NANOSCALE 2021; 13:2338-2349. [PMID: 33438712 DOI: 10.1039/d0nr08083g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Malaria is a life-threatening epidemic disease with half of the world's population at risk. Although its incidence rate has fallen since 2010, this ratio dramatically stalled between 2014 and 2018. New fast and optimized tools in vaccine analysis and seroconversion testing are critically needed. We developed a clinical diagnostic device based on piezo-actuated nanoresonators that perform as quantitative in situ calibrated nano-bio sensors for specific detection of multiple target molecules in serum samples. The immunoassay successfully diagnoses humoral immune responses induced by malaria vaccine candidates and reveals the timeline and stage of the infection. We applied the newly developed strategy to a variety of different samples, from pure antibody/vaccine solutions, to blood samples from clinical trials on both naïve and pre-exposed malaria volunteers from sub-Saharan countries. Our nanomechanical assay provides a direct one-step label-free quantitative immunoassay that is on par with the gold-standard, multi-step enzyme-linked immunosorbent assay (ELISA). We achieve a limit of detection of few pg ml-1, or sub-pM concentrations. The 6 μl sample volume allows more than 50 experiments from one finger prick. Furthermore, we simultaneously detected multiple analytes by differential functionalization of multiple sensors in parallel. The inherent differential read-out with in situ controls reduces false positive results. Due to the faster turnaround time, the minimal volume required and the automatized handling system, this technique has great potential for miniaturization and routine diagnostics in pandemic emergencies.
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Affiliation(s)
- Giulio Brunetti
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Francesco Padovani
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland. and Institute of Functional Epigenetics, Helmholtz Zentrum München (HMGU), Neuherberg 85764, Germany
| | - Annalisa De Pastina
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Chiara Rotella
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Amy Monahan
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | | | - Said A Jongo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Salim Abdulla
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | | | - Gerd Pluschke
- Medical Parasitology and Infection Biology Department, Molecular Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland and University of Basel, Switzerland
| | - Claudia Daubenberger
- University of Basel, Switzerland and Medical Parasitology and Infection Biology Department, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.
| | - Martin Hegner
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
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Mills B, Isaac RE, Foster R. Metalloaminopeptidases of the Protozoan Parasite Plasmodium falciparum as Targets for the Discovery of Novel Antimalarial Drugs. J Med Chem 2021; 64:1763-1785. [PMID: 33534577 DOI: 10.1021/acs.jmedchem.0c01721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Malaria poses a significant threat to approximately half of the world's population with an annual death toll close to half a million. The emergence of resistance to front-line antimalarials in the most lethal human parasite species, Plasmodium falciparum (Pf), threatens progress made in malaria control. The prospect of losing the efficacy of antimalarial drugs is driving the search for small molecules with new modes of action. Asexual reproduction of the parasite is critically dependent on the recycling of amino acids through catabolism of hemoglobin (Hb), which makes metalloaminopeptidases (MAPs) attractive targets for the development of new drugs. The Pf genome encodes eight MAPs, some of which have been found to be essential for parasite survival. In this article, we discuss the biological structure and function of each MAP within the Pf genome, along with the drug discovery efforts that have been undertaken to identify novel antimalarial candidates of therapeutic value.
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Affiliation(s)
- Belinda Mills
- School of Chemistry, University of Leeds, Leeds, U.K., LS2 9JT
| | - R Elwyn Isaac
- School of Biology, University of Leeds, Leeds, U.K., LS2 9JT
| | - Richard Foster
- School of Chemistry, University of Leeds, Leeds, U.K., LS2 9JT
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20
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Thompson HA, Hogan AB, Walker PGT, White MT, Cunnington AJ, Ockenhouse CF, Ghani AC. Modelling the roles of antibody titre and avidity in protection from Plasmodium falciparum malaria infection following RTS,S/AS01 vaccination. Vaccine 2020; 38:7498-7507. [PMID: 33041104 PMCID: PMC7607256 DOI: 10.1016/j.vaccine.2020.09.069] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 08/21/2020] [Accepted: 09/24/2020] [Indexed: 12/16/2022]
Abstract
Models capturing key malaria life-cycle stages can help us evaluate vaccine candidates. Model fitting revealed antibody avidity to be an important determinant of RTS,S vaccine efficacy. High avidity and titre were associated with increased levels of vaccine efficacy. Did not identify any thresholds of protection for either immune marker.
Anti-circumsporozoite antibody titres have been established as an essential indicator for evaluating the immunogenicity and protective capacity of the RTS,S/AS01 malaria vaccine. However, a new delayed-fractional dose regime of the vaccine was recently shown to increase vaccine efficacy, from 62.5% (95% CI 29.4–80.1%) under the original dosing schedule to 86.7% (95% CI, 66.8–94.6%) without a corresponding increase in antibody titres. Here we reanalyse the antibody data from this challenge trial to determine whether IgG avidity may help to explain efficacy better than IgG titre alone by adapting a within-host mathematical model of sporozoite inoculation. We demonstrate that a model incorporating titre and avidity provides a substantially better fit to the data than titre alone. These results also suggest that in individuals with a high antibody titre response that also show high avidity (both metrics in the top tercile of observed values) delayed-fractional vaccination provided near perfect protection upon first challenge (98.2% [95% Credible Interval 91.6–99.7%]). This finding suggests that the quality of the vaccine induced antibody response is likely to be an important determinant in the development of highly efficacious pre-erythrocytic vaccines against malaria.
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Affiliation(s)
- Hayley A Thompson
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom.
| | - Alexandra B Hogan
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Patrick G T Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Michael T White
- Malaria: Parasites and Hosts, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | | | | | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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21
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Cunningham SA, Shaikh NI, Nhacolo A, Raghunathan PL, Kotloff K, Naser AM, Mengesha MM, Adedini SA, Misore T, Onuwchekwa UU, Worrell MC, El Arifeen S, Assefa N, Chowdhury AI, Kaiser R, Madhi SA, Mehta A, Obor D, Sacoor C, Sow SO, Tapia MD, Wilkinson AL, Breiman RF. Health and Demographic Surveillance Systems Within the Child Health and Mortality Prevention Surveillance Network. Clin Infect Dis 2020; 69:S274-S279. [PMID: 31598663 PMCID: PMC6785673 DOI: 10.1093/cid/ciz609] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Health and demographic surveillance systems (HDSSs) provide a foundation for characterizing and defining priorities and strategies for improving population health. The Child Health and Mortality Prevention Surveillance (CHAMPS) project aims to inform policy to prevent child deaths through generating causes of death from surveillance data combined with innovative diagnostic and laboratory methods. Six of the 7 sites that constitute the CHAMPS network have active HDSSs: Mozambique, Mali, Ethiopia, Kenya, Bangladesh, and South Africa; the seventh, in Sierra Leone, is in the early planning stages. This article describes the network of CHAMPS HDSSs and their role in the CHAMPS project. To generate actionable health and demographic data to prevent child deaths, the network depends on reliable demographic surveillance, and the HDSSs play this crucial role.
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Affiliation(s)
| | - Nida I Shaikh
- Emory Global Health Institute, Emory University, Atlanta, Georgia, USA
| | - Ariel Nhacolo
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Pratima L Raghunathan
- Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Karen Kotloff
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Abu Mohd Naser
- Emory Global Health Institute, Emory University, Atlanta, Georgia, USA
| | - Melkamu M Mengesha
- College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Sunday A Adedini
- Medical Research Council, Respiratory and Meningeal Pathogen Research Unit, University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa.,Demography and Population Studies Program, Schools of Public Health and Social Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Uma U Onuwchekwa
- Centre pour le Développement des Vaccins (CVD-Mali), Ministère de la Santé, Bamako, Mali
| | - Mary Claire Worrell
- Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Nega Assefa
- College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | | | - Reinhard Kaiser
- US Centers for Disease Control and Prevention-Sierra Leone, Freetown, Sierra Leone
| | - Shabir A Madhi
- Medical Research Council, Respiratory and Meningeal Pathogen Research Unit, University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa.,Department of Science and Technology/National Research Foundation, Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa
| | - Ashka Mehta
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David Obor
- Kenya Medical Research Institute, Kisumu, Kenya
| | - Charfudin Sacoor
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Samba O Sow
- Centre pour le Développement des Vaccins (CVD-Mali), Ministère de la Santé, Bamako, Mali
| | - Milagritos D Tapia
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Amanda L Wilkinson
- Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Robert F Breiman
- Emory Global Health Institute, Emory University, Atlanta, Georgia, USA
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22
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Singh JA. The Case for Why Africa Should Host COVID-19 Candidate Vaccine Trials. J Infect Dis 2020; 222:351-355. [PMID: 32492144 PMCID: PMC7313920 DOI: 10.1093/infdis/jiaa303] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/27/2020] [Indexed: 01/29/2023] Open
Abstract
In response to provocative comments by 2 European clinicians and scientists, the World Health Organization Director General has declared that Africa will not host COVID-19 vaccine trials. Such a stance risks stigmatizing COVID-19 vaccine trials in Africa and depriving Africa of critical research. To the contrary, there is a critical need for Africa to host COVID-19 vaccine trials on public health, scientific, and ethics grounds.
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Affiliation(s)
- Jerome Amir Singh
- Centre for the AIDS Programme of Research in South Africa, Durban, South Africa
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23
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Parzych EM, Miura K, Long CA, Burns JM. Maintaining immunogenicity of blood stage and sexual stage subunit malaria vaccines when formulated in combination. PLoS One 2020; 15:e0232355. [PMID: 32348377 PMCID: PMC7190115 DOI: 10.1371/journal.pone.0232355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/13/2020] [Indexed: 11/18/2022] Open
Abstract
Background Eradication of Plasmodium falciparum malaria will likely require a multivalent vaccine, but the development of a highly efficacious subunit-based formulation has been challenging. We previously showed that production and immunogenicity of two leading vaccine targets, PfMSP119 (blood-stage) and Pfs25 (sexual stage), could be enhanced upon genetic fusion to merozoite surface protein 8 (PfMSP8). Here, we sought to optimize a Pfs25-based formulation for use in combination with rPfMSP1/8 with the goal of maintaining the immunogenicity of each subunit. Methods Comparative mouse studies were conducted to assess the effects of adjuvant selection (Alhydrogel vs. glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE)) and antigen dose (2.5 vs. 0.5 μg) on the induction of anti-Pfs25 immune responses. The antibody response (magnitude, IgG subclass profile, and transmission-reducing activity (TRA)) and cellular responses (proliferation, cytokine production) generated in response to each formulation were assessed. Similarly, immunogenicity of a bivalent vaccine containing rPfMSP1/8 and rPfs25/8 was evaluated. Results Alum-based formulations elicited strong and comparable humoral and cellular responses regardless of antigen form (unfused rPfs25 or chimeric rPfs25/8) or dose. In contrast, GLA-SE based formulations elicited differential responses as a function of both parameters, with 2.5 μg of rPfs25/8 inducing the highest titers of functional anti-Pfs25 antibodies. Based on these data, chimeric rPfs25/8 was selected and tested in a bivalent formulation with rPfMSP1/8. Strong antibody titers against Pfs25 and PfMSP119 domains were induced with GLA-SE based formulations, with no indication of antigenic competition. Conclusions We were able to generate an immunogenic bivalent vaccine designed to target multiple parasite stages that could reduce both clinical disease and parasite transmission. The use of the same PfMSP8 carrier for two different vaccine components was effective in this bivalent formulation. As such, the incorporation of additional protective targets fused to the PfMSP8 carrier into the formulation should be feasible, further broadening the protective response.
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Affiliation(s)
- Elizabeth M. Parzych
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Carole A. Long
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - James M. Burns
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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24
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Kurtovic L, Atre T, Feng G, Wines BD, Chan JA, Boyle MJ, Drew DR, Hogarth PM, Fowkes FJI, Bergmann-Leitner ES, Beeson JG. Multi-functional antibodies are induced by the RTS,S malaria vaccine and associated with protection in a phase I/IIa trial. J Infect Dis 2020; 224:1128-1138. [PMID: 32236404 PMCID: PMC8514181 DOI: 10.1093/infdis/jiaa144] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/30/2020] [Indexed: 01/24/2023] Open
Abstract
Background RTS,S is the leading malaria vaccine candidate but only confers partial efficacy against malaria in children. RTS,S is based on the major Plasmodium falciparum sporozoite surface antigen, circumsporozoite protein (CSP). The induction of anti-CSP antibodies is important for protection; however, it is unclear how these protective antibodies function. Methods We quantified the induction of functional anti-CSP antibody responses in healthy malaria-naive adults (N = 45) vaccinated with RTS,S/AS01. This included the ability to mediate effector functions via the fragment crystallizable (Fc) region, such as interacting with human complement proteins and Fcγ-receptors (FcγRs) that are expressed on immune cells, which promote various immunological functions. Results Our major findings were (1) RTS,S-induced antibodies mediated Fc-dependent effector functions, (2) functional antibodies were generally highest after the second vaccine dose, (3) functional antibodies targeted multiple regions of CSP, (4) participants with higher levels of functional antibodies had a reduced probability of developing parasitemia following homologous challenge (P < .05), and (5) nonprotected subjects had higher levels of anti-CSP IgM. Conclusions Our data suggest a role for Fc-dependent antibody effector functions in RTS,S-induced immunity. Enhancing the induction of these functional activities may be a strategy to improve the protective efficacy of RTS,S or other malaria vaccines. Clinical Trials Registration NCT00075049
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Affiliation(s)
- Liriye Kurtovic
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Tanmaya Atre
- Malaria Vaccine Branch, US Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, United States
| | | | - Bruce D Wines
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Clinical Pathology, The University of Melbourne, Melbourne, Australia
| | - Jo-Anne Chan
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Michelle J Boyle
- Burnet Institute, Melbourne, Australia.,QIMR Berghofer, Herston, Australia
| | | | - P Mark Hogarth
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Clinical Pathology, The University of Melbourne, Melbourne, Australia
| | - Freya J I Fowkes
- Burnet Institute, Melbourne, Australia.,Department of Epidemiology and Preventative Medicine and Department of Infectious Diseases, Monash University, Melbourne, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Elke S Bergmann-Leitner
- Malaria Vaccine Branch, US Military Malaria Research Program, Walter Reed Army Institute of Research, Silver Spring, United States
| | - James G Beeson
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia.,Department of Medicine, The University of Melbourne, Parkville, Australia
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25
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Molina-Franky J, Cuy-Chaparro L, Camargo A, Reyes C, Gómez M, Salamanca DR, Patarroyo MA, Patarroyo ME. Plasmodium falciparum pre-erythrocytic stage vaccine development. Malar J 2020; 19:56. [PMID: 32013956 PMCID: PMC6998842 DOI: 10.1186/s12936-020-3141-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/25/2020] [Indexed: 12/13/2022] Open
Abstract
Worldwide strategies between 2010 and 2017 aimed at controlling malarial parasites (mainly Plasmodium falciparum) led to a reduction of just 18% regarding disease incidence rates. Many biologically-derived anti-malarial vaccine candidates have been developed to date; this has involved using many experimental animals, an immense amount of work and the investment of millions of dollars. This review provides an overview of the current state and the main results of clinical trials for sporozoite-targeting vaccines (i.e. the parasite stage infecting the liver) carried out by research groups in areas having variable malaria transmission rates. However, none has led to promising results regarding the effective control of the disease, thereby making it necessary to complement such efforts at finding/introducing new vaccine candidates by adopting a multi-epitope, multi-stage approach, based on minimal subunits of the main sporozoite proteins involved in the invasion of the liver.
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Affiliation(s)
- Jessica Molina-Franky
- Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia.,Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Laura Cuy-Chaparro
- Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia.,Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Anny Camargo
- Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia.,Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - César Reyes
- PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Animal Science Faculty, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A), Bogotá, Colombia.,3D Structures Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Marcela Gómez
- Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia.,Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - David Ricardo Salamanca
- Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia.,Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,PhD Program in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Alfonso Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia. .,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia.
| | - Manuel Elkin Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia. .,Medical School, Universidad Nacional de Colombia, Bogotá, Colombia.
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26
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von Seidlein L, Hanboonkunupakarn B, Jittamala P, Pongsuwan P, Chotivanich K, Tarning J, Hoglund RM, Winterberg M, Mukaka M, Peerawaranun P, Sirithiranont P, Doran Z, Ockenhouse CF, Ivinson K, Lee C, Birkett AJ, Kaslow DC, Singhasivanon P, Day NPJ, Dondorp AM, White NJ, Pukrittayakamee S. Combining antimalarial drugs and vaccine for malaria elimination campaigns: a randomized safety and immunogenicity trial of RTS,S/AS01 administered with dihydroartemisinin, piperaquine, and primaquine in healthy Thai adult volunteers. Hum Vaccin Immunother 2019; 16:33-41. [PMID: 31306084 PMCID: PMC7012096 DOI: 10.1080/21645515.2019.1643675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Introduction: RTS,S/AS01 is currently the most advanced malaria vaccine but provides incomplete, short-term protection. It was developed for use within the expanded program on immunizations (EPI) for African children. Another use could be adding mass RTS,S/AS01 vaccination to the integrated malaria elimination strategy in the Greater Mekong Subregion (GMS), where multidrug-resistant P.falciparum strains have emerged and spread. Prior to evaluating RTS,S/AS01 in large-scale trials we assessed whether the vaccine, administered with and without antimalarial drugs, is safe and immunogenic in Asian populations. Methods: An open-label, randomized, controlled phase 2 trial was conducted in healthy, adult Thai volunteers. Seven vaccine regimens with and without antimalarial drugs (dihydroartemisinin-piperaquine plus a single low dose primaquine) were assessed. Antibody titres against the PfCSP full-length (NANP) 6, PfCSP anti-C–term, PfCSP full-length (N + C-Terminal) were measured by standard enzyme-linked immunosorbent assays. Liquid chromatography was used to measure piperaquine, primaquine and carboxy-primaquine concentrations. Results: 193 volunteers were enrolled and 186 study participants completed the 6 months follow-up period. One month after the last vaccination all study participants had seroconverted to the PfCSP (NANP)6, and the PfCSP Full Length (N + C-Terminal). More than 90% had seroconverted to the Pfanti-C-Term CSP. There was no indication that drug concentrations were influenced by vaccine regimens or the antibody levels by the drug regimens. Adverse events were similarly distributed between the seven treatment groups. No serious adverse events attributable to the study interventions were detected. Conclusion: This study found that RTS,S/AS01 with and without dihydroartemisinin-piperaquine plus a single low dose primaquine was safe and immunogenic in a healthy, adult Asian population.
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Affiliation(s)
- Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Borimas Hanboonkunupakarn
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Podjanee Jittamala
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pongphaya Pongsuwan
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kesinee Chotivanich
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Richard M Hoglund
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Markus Winterberg
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Pimnara Peerawaranun
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pasathorn Sirithiranont
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Zoe Doran
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | | | - Cynthia Lee
- PATH's Malaria Vaccine Initiative, Seattle, WA, USA
| | | | | | | | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sasithon Pukrittayakamee
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,The Royal Society of Thailand, Dusit, Bangkok, Thailand
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27
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Anti-malarial, cytotoxicity and molecular docking studies of quinolinyl chalcones as potential anti-malarial agent. J Comput Aided Mol Des 2019; 33:677-688. [DOI: 10.1007/s10822-019-00210-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 05/31/2019] [Indexed: 10/26/2022]
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28
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Concentration and avidity of antibodies to different circumsporozoite epitopes correlate with RTS,S/AS01E malaria vaccine efficacy. Nat Commun 2019; 10:2174. [PMID: 31092823 PMCID: PMC6520358 DOI: 10.1038/s41467-019-10195-z] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 04/26/2019] [Indexed: 11/08/2022] Open
Abstract
RTS,S/AS01E has been tested in a phase 3 malaria vaccine study with partial efficacy in African children and infants. In a cohort of 1028 subjects from one low (Bagomoyo) and two high (Nanoro, Kintampo) malaria transmission sites, we analysed IgG plasma/serum concentration and avidity to CSP (NANP-repeat and C-terminal domains) after a 3-dose vaccination against time to clinical malaria events during 12-months. Here we report that RTS,S/AS01E induces substantial increases in IgG levels from pre- to post-vaccination (p < 0.001), higher in NANP than C-terminus (2855 vs 1297 proportional change between means), and higher concentrations and avidities in children than infants (p < 0.001). Baseline CSP IgG levels are elevated in malaria cases than controls (p < 0.001). Both, IgG magnitude to NANP (hazard ratio [95% confidence interval] 0.61 [0.48-0.76]) and avidity to C-terminus (0.07 [0.05-0.90]) post-vaccination are significantly associated with vaccine efficacy. IgG avidity to the C-terminus emerges as a significant contributor to RTS,S/AS01E-mediated protection.
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29
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Khan S, Parrillo M, Gutierrez AH, Terry FE, Moise L, Martin WD, De Groot AS. Immune escape and immune camouflage may reduce the efficacy of RTS,S vaccine in Malawi. Hum Vaccin Immunother 2019; 16:214-227. [PMID: 30614773 PMCID: PMC7062414 DOI: 10.1080/21645515.2018.1560772] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The RTS,S/AS01 malaria vaccine will undergo a pilot vaccination study in sub-Saharan Africa beginning in 2019. RTS,S/AS01 Phase III trials reported an efficacy of 28.3% (children 5–17 months) and 18.3% (infants 6–12 weeks), with substantial variability across study sites. We postulated that the relatively low efficacy of the RTS,S vaccine and variability across sites may be due to lack of T-cell epitopes in the vaccine antigen, and due to the HLA distribution of the vaccinated population, and/or due to ‘immune camouflage’, an immune escape mechanism. To examine these hypotheses, we used immunoinformatics tools to compare T helper epitopes contained in RTS,S vaccine antigens with Plasmodium falciparum circumsporozoite protein (CSP) variants isolated from infected individuals in Malawi. The prevalence of epitopes restricted by specific HLA-DRB1 alleles was inversely associated with prevalence of the HLA-DRB1 allele in the Malawi study population, suggesting immune escape. In addition, T-cell epitopes in the CSP of strains circulating in Malawi were more often restricted by low-frequency HLA-DRB1 alleles in the population. Furthermore, T-cell epitopes that were highly conserved across CSP variants in Malawi possessed TCR-facing residues that were highly conserved in the human proteome, potentially reducing T-cell help through tolerance. The CSP component of the RTS,S vaccine also exhibited a low degree of T-cell epitope relatedness to circulating variants. These results suggest that RTS,S vaccine efficacy may be impacted by low T-cell epitope content, reduced presentation of T-cell epitopes by prevalent HLA-DRB1, high potential for human-cross-reactivity, and limited conservation with the CSP of circulating malaria strains.
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Affiliation(s)
- Sundos Khan
- Institute for Immunology and Informatics, Department of Cell and Molecular Biology, University of Rhode Island, Providence, RI, USA
| | - Matthew Parrillo
- Institute for Immunology and Informatics, Department of Cell and Molecular Biology, University of Rhode Island, Providence, RI, USA
| | | | | | - Leonard Moise
- Institute for Immunology and Informatics, Department of Cell and Molecular Biology, University of Rhode Island, Providence, RI, USA.,EpiVax, Inc., Providence, RI, USA
| | | | - Anne S De Groot
- Institute for Immunology and Informatics, Department of Cell and Molecular Biology, University of Rhode Island, Providence, RI, USA.,EpiVax, Inc., Providence, RI, USA
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Beeson JG, Kurtovic L, Dobaño C, Opi DH, Chan JA, Feng G, Good MF, Reiling L, Boyle MJ. Challenges and strategies for developing efficacious and long-lasting malaria vaccines. Sci Transl Med 2019; 11:11/474/eaau1458. [DOI: 10.1126/scitranslmed.aau1458] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/05/2018] [Accepted: 11/02/2018] [Indexed: 12/24/2022]
Abstract
Although there has been major recent progress in malaria vaccine development, substantial challenges remain for achieving highly efficacious and durable vaccines against Plasmodium falciparum and Plasmodium vivax malaria. Greater knowledge of mechanisms and key targets of immunity are needed to accomplish this goal, together with new strategies for generating potent, long-lasting, functional immunity against multiple antigens. Implementation considerations in endemic areas will ultimately affect vaccine effectiveness, so innovations to simplify and enhance delivery are also needed. Whereas challenges remain, recent exciting progress and emerging knowledge promise hope for the future of malaria vaccines.
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31
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Vogel M, Bachmann MF. Immunogenicity and Immunodominance in Antibody Responses. Curr Top Microbiol Immunol 2019; 428:89-102. [PMID: 30919087 DOI: 10.1007/82_2019_160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A large number of vaccines exist that control many of the most important infectious diseases. Despite these successes, there remain many pathogens without effective prophylactic vaccines. Notwithstanding strong difference in the biology of these infectious agents, there exist common problems in vaccine design. Many infectious agents have highly variable surface antigens and/or unusually high antibody levels are required for protection. Such high variability may be addressed by using conserved epitopes and these are, however, usually difficult to display with the right conformation in an immunogenic fashion. Exceptionally high antibody titers may be achieved using life vectors or virus-like display of the epitopes. Hence, an important goal in modern vaccinology is to induce high antibody responses against fragile antigens.
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Affiliation(s)
- Monique Vogel
- Department of Rheumatology, Immunology and Allergology, University Hospital Bern, Sahlihaus 2, CH-3010, Bern, Switzerland
| | - Martin F Bachmann
- Department of Rheumatology, Immunology and Allergology, University Hospital Bern, Sahlihaus 2, CH-3010, Bern, Switzerland. .,The Jenner Institute, University of Oxford, Oxford, UK.
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32
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Ubillos I, Ayestaran A, Nhabomba AJ, Dosoo D, Vidal M, Jiménez A, Jairoce C, Sanz H, Aguilar R, Williams NA, Díez-Padrisa N, Mpina M, Sorgho H, Agnandji ST, Kariuki S, Mordmüller B, Daubenberger C, Asante KP, Owusu-Agyei S, Sacarlal J, Aide P, Aponte JJ, Dutta S, Gyan B, Campo JJ, Valim C, Moncunill G, Dobaño C. Baseline exposure, antibody subclass, and hepatitis B response differentially affect malaria protective immunity following RTS,S/AS01E vaccination in African children. BMC Med 2018; 16:197. [PMID: 30376866 PMCID: PMC6208122 DOI: 10.1186/s12916-018-1186-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 10/01/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The RTS,S/AS01E vaccine provides partial protection against malaria in African children, but immune responses have only been partially characterized and do not reliably predict protective efficacy. We aimed to evaluate comprehensively the immunogenicity of the vaccine at peak response, the factors affecting it, and the antibodies associated with protection against clinical malaria in young African children participating in the multicenter phase 3 trial for licensure. METHODS We measured total IgM, IgG, and IgG1-4 subclass antibodies to three constructs of the Plasmodium falciparum circumsporozoite protein (CSP) and hepatitis B surface antigen (HBsAg) that are part of the RTS,S vaccine, by quantitative suspension array technology. Plasma and serum samples were analyzed in 195 infants and children from two sites in Ghana (Kintampo) and Mozambique (Manhiça) with different transmission intensities using a case-control study design. We applied regression models and machine learning techniques to analyze immunogenicity, correlates of protection, and factors affecting them. RESULTS RTS,S/AS01E induced IgM and IgG, predominantly IgG1 and IgG3, but also IgG2 and IgG4, subclass responses. Age, site, previous malaria episodes, and baseline characteristics including antibodies to CSP and other antigens reflecting malaria exposure and maternal IgGs, nutritional status, and hemoglobin concentration, significantly affected vaccine immunogenicity. We identified distinct signatures of malaria protection and risk in RTS,S/AS01E but not in comparator vaccinees. IgG2 and IgG4 responses to RTS,S antigens post-vaccination, and anti-CSP and anti-P. falciparum antibody levels pre-vaccination, were associated with malaria risk over 1-year follow-up. In contrast, antibody responses to HBsAg (all isotypes, subclasses, and timepoints) and post-vaccination IgG1 and IgG3 to CSP C-terminus and NANP were associated with protection. Age and site affected the relative contribution of responses in the correlates identified. CONCLUSIONS Cytophilic IgG responses to the C-terminal and NANP repeat regions of CSP and anti-HBsAg antibodies induced by RTS,S/AS01E vaccination were associated with malaria protection. In contrast, higher malaria exposure at baseline and non-cytophilic IgG responses to CSP were associated with disease risk. Data provide new correlates of vaccine success and failure in African children and reveal key insights into the mode of action that can guide development of more efficacious next-generation vaccines.
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Affiliation(s)
- Itziar Ubillos
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Aintzane Ayestaran
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Augusto J Nhabomba
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - David Dosoo
- Kintampo Health Research Centre, Kintampo, Ghana
| | - Marta Vidal
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Alfons Jiménez
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Spanish Consortium for Research in Epidemiology and Public Health (CIBERESP), Barcelona, Spain
| | - Chenjerai Jairoce
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Hèctor Sanz
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Ruth Aguilar
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Nana Aba Williams
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Núria Díez-Padrisa
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Maximilian Mpina
- Ifakara Health Institute, Bagamoyo Research and Training Center, P.O. Box 74, Bagamoyo, Tanzania
| | - Hermann Sorgho
- Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon.,Institute of Tropical Medicine and German Center for Infection Research, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
| | - Simon Kariuki
- Kenya Medical Research Institute (KEMRI)/Centre for Global Health Research, Kisumu, Kenya
| | - Benjamin Mordmüller
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
| | - Claudia Daubenberger
- Ifakara Health Institute, Bagamoyo Research and Training Center, P.O. Box 74, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
| | | | | | - Jahit Sacarlal
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique.,Facultade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - John J Aponte
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Sheetij Dutta
- Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, USA
| | - Ben Gyan
- Kintampo Health Research Centre, Kintampo, Ghana.,Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Joseph J Campo
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Clarissa Valim
- Department of Osteopathic Medical Specialties, Michigan State University, 909 Fee Road, Room B 309 West Fee Hall, East Lansing, MI, 48824, USA.,Department of Immunology and Infectious Diseases, Harvard T.H. Chen School of Public Health, 675 Huntington Ave., Boston, MA, 02115, USA
| | - Gemma Moncunill
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain. .,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique.
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Safety and Immunogenicity of Seven Dosing Regimens of the Candidate RTS,S/AS01E Malaria Vaccine Integrated Within an Expanded Program on Immunization Regimen: A Phase II, Single-Center, Open, Controlled Trial in Infants in Malawi. Pediatr Infect Dis J 2018; 37:483-491. [PMID: 29432383 DOI: 10.1097/inf.0000000000001937] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND In a phase III trial, the RTS,S/AS01 malaria vaccine produced lower anti-circumsporozoite (CS) antibody titers when co-administered with Expanded Programme on Immunization vaccines (0-, 1- and 2-month schedule) at 6 to 12 weeks compared with 5 to 17 months at first vaccination. Alternative infant immunization schedules within the Expanded Programme on Immunization were investigated. METHODS This phase II, open, single-site (Blantyre, Malawi) trial was conducted in infants 1 to 7 days of age. Subjects were equally randomized across 7 groups to receive 3 doses of RTS,S/AS01E at time points that included ≤7 days, 6, 10, 14 and 26 weeks, and 9 months. All RTS,S/AS01E groups plus a control group (without RTS,S/AS01E) received Bacillus Calmette-Guérin + oral poliovirus vaccine at ≤7 days, diphtheria, tetanus, whole-cell pertussis, hepatitis B and Haemophilus influenzae type b vaccine + oral poliovirus vaccine at 6, 10, and 14 weeks and measles vaccine at 9 months; one RTS,S/AS01E group and the control additionally received hepatitis B vaccination at ≤7 days. Serum anti-CS antibody geometric mean concentration (GMC; enzyme-linked immunosorbent assay) and safety were assessed up to age 18 months. RESULTS Of the 480 infants enrolled, 391 completed the study. No causally related serious adverse event was reported. A higher frequency of fever within 7 days of RTS,S/AS01E vaccination compared with control was observed. Compared with the standard 6-, 10-, 14-week schedule, anti-CS antibody GMC ratios post-dose 3 were significantly higher in the 10-, 14- and 26-week group only (ratio 1.80; 95% confidence interval, 1.24-2.60); RTS,S/AS01E vaccination at ≤7 days and 10 and 14 weeks produced significantly lower anti-CS GMCs (ratio 0.59; 95% confidence interval, 0.38-0.92). CONCLUSIONS Initiation of RTS,S/AS01E vaccination above 6 weeks of age tended to improve anti-CS antibody responses. Neonatal vaccination was well tolerated but produced a comparatively lower immune response.
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Zhou Y, Wang H, Zhuo Y, Chai Y, Yuan R. Highly Efficient Electrochemiluminescent Silver Nanoclusters/Titanium Oxide Nanomaterials as a Signal Probe for Ferrocene-Driven Light Switch Bioanalysis. Anal Chem 2017; 89:3732-3738. [DOI: 10.1021/acs.analchem.7b00090] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Ying Zhou
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People’s Republic of China
| | - Haijun Wang
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People’s Republic of China
| | - Ying Zhuo
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People’s Republic of China
| | - Yaqin Chai
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People’s Republic of China
| | - Ruo Yuan
- Key Laboratory of Luminescence
and Real-Time Analytical Chemistry (Southwest University), Ministry
of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People’s Republic of China
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Systems analysis of protective immune responses to RTS,S malaria vaccination in humans. Proc Natl Acad Sci U S A 2017; 114:2425-2430. [PMID: 28193898 DOI: 10.1073/pnas.1621489114] [Citation(s) in RCA: 185] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
RTS,S is an advanced malaria vaccine candidate and confers significant protection against Plasmodium falciparum infection in humans. Little is known about the molecular mechanisms driving vaccine immunity. Here, we applied a systems biology approach to study immune responses in subjects receiving three consecutive immunizations with RTS,S (RRR), or in those receiving two immunizations of RTS,S/AS01 following a primary immunization with adenovirus 35 (Ad35) (ARR) vector expressing circumsporozoite protein. Subsequent controlled human malaria challenge (CHMI) of the vaccinees with Plasmodium-infected mosquitoes, 3 wk after the final immunization, resulted in ∼50% protection in both groups of vaccinees. Circumsporozoite protein (CSP)-specific antibody titers, prechallenge, were associated with protection in the RRR group. In contrast, ARR-induced lower antibody responses, and protection was associated with polyfunctional CD4+ T-cell responses 2 wk after priming with Ad35. Molecular signatures of B and plasma cells detected in PBMCs were highly correlated with antibody titers prechallenge and protection in the RRR cohort. In contrast, early signatures of innate immunity and dendritic cell activation were highly associated with protection in the ARR cohort. For both vaccine regimens, natural killer (NK) cell signatures negatively correlated with and predicted protection. These results suggest that protective immunity against P. falciparum can be achieved via multiple mechanisms and highlight the utility of systems approaches in defining molecular correlates of protection to vaccination.
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36
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Radin K, Clement F, Jongert E, Sterckx YGJ, Ockenhouse C, Regules J, Lemiale F, Leroux-Roels G. A monoclonal antibody-based immunoassay to measure the antibody response against the repeat region of the circumsporozoite protein of Plasmodium falciparum. Malar J 2016; 15:543. [PMID: 27825382 PMCID: PMC5101676 DOI: 10.1186/s12936-016-1596-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 10/31/2016] [Indexed: 12/15/2022] Open
Abstract
Background The malaria vaccine candidate RTS,S/AS01 (GSK Vaccines) induces high IgG concentration against the circumsporozoite protein (CSP) of Plasmodium falciparum. In human vaccine recipients circulating anti-CSP antibody concentrations are associated with protection against infection but appear not to be the correlate of protection. However, in a humanized mouse model of malaria infection prophylactic administration of a human monoclonal antibody (MAL1C), derived from a RTS,S/AS01-immunized volunteer, directed against the CSP repeat region, conveyed full protection in a dose-dependent manner suggesting that antibodies alone are able to prevent P. falciparum infection when present in sufficiently high concentrations. A competition ELISA was developed to measure the presence of MAL1C-like antibodies in polyclonal sera from RTS,S/AS01 vaccine recipients and study their possible contribution to protection against infection. Results MAL1C-like antibodies present in polyclonal vaccine-induced sera were evaluated for their ability to compete with biotinylated monoclonal antibody MAL1C for binding sites on the capture antigen consisting of the recombinant protein encompassing 32 NANP repeats of CSP (R32LR). Serum samples were taken at different time points from participants in two RTS,S/AS01 vaccine studies (NCT01366534 and NCT01857869). Vaccine-induced protection status of the study participants was determined based on the outcome of experimental challenge with infected mosquito bites after vaccination. Optimal conditions were established to reliably detect MAL1C-like antibodies in polyclonal sera. Polyclonal anti-CSP antibodies and MAL1C-like antibody content were measured in 276 serum samples from RTS,S/AS01 vaccine recipients using the standard ELISA and MAL-1C competition ELISA, respectively. A strong correlation was observed between the results from these assays. However, no correlation was found between the results of either assay and protection against infection. Conclusions The competition ELISA to measure MAL1C-like antibodies in polyclonal sera from RTS,S/AS01 vaccine recipients was robust and reliable but did not reveal the elusive correlate of protection. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1596-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kristina Radin
- Center for Vaccinology (CEVAC), Ghent University, Ghent, Belgium
| | - Frederic Clement
- Center for Vaccinology (CEVAC), Ghent University, Ghent, Belgium
| | - Erik Jongert
- GSK Vaccines, Rue de l'Institut 89, B-1330, Rixensart, Belgium
| | - Yann G J Sterckx
- Structural Biology Research Center (SBRC), VIB, Pleinlaan 2, B-1050, Brussels, Belgium.,Research Unit for Cellular and Molecular Immunology (CMIM), VUB, Pleinlaan 2, B-1050, Brussels, Belgium
| | - Christian Ockenhouse
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
| | - Jason Regules
- Walter Reed Army Institute of Research (WRAIR), 503 Robert Grant Ave., Silver Spring, MD, 20910, USA
| | - Franck Lemiale
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
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Abstract
Adjuvants are substances added to vaccines to improve their immunogenicity. Used for more than 80 years, aluminum, the first adjuvant in human vaccines, proved insufficient to develop vaccines that could protect against new challenging pathogens such as HIV and malaria. New adjuvants and new combinations of adjuvants (Adjuvant Systems) have opened the door to the delivery of improved and new vaccines against re-emerging and difficult pathogens. Adjuvant Systems concept started through serendipity. The access to new developments in technology, microbiology and immunology have been instrumental for the dicephering of what they do and how they do it. This knowledge opens the door to more rational vaccine design with implications for developing new and better vaccines.
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Sacoor C, Nhacolo A, Nhalungo D, Aponte JJ, Bassat Q, Augusto O, Mandomando I, Sacarlal J, Lauchande N, Sigaúque B, Alonso P, Macete E, Munguambe K, Guinovart C, Aide P, Menendez C, Acácio S, Quelhas D, Sevene E, Nhampossa T. Profile: Manhiça Health Research Centre (Manhiça HDSS). Int J Epidemiol 2016; 42:1309-18. [PMID: 24159076 DOI: 10.1093/ije/dyt148] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Manhiça Health Research Centre, established in 1996 in a rural area of southern Mozambique, currently follows around 92 000 individuals living in approximately 20 000 enumerated and geo-positioned households. Its main strength is the possibility of linking demographic data and clinical data to promote and conduct biomedical research in priority health areas. Socio-demographic data are updated twice a year and clinical data are collected on a daily basis. The data collected in Manhiça HDSS comprises household and individual characteristics, household socio-economic assets, vital data, migration, individual health history and cause of death, among others. Studies conducted in this HDSS contributed to guide the health authorities and decision-making bodies to define or adjust health policies such as the introduction of Mozambique's expanded programme of immunization with different vaccines (Haemophilus influenzae type b, Pneumococcus) or the development of the concept of Intermittent Preventive Treatment for Infants (IPTi) that led to the World Health Organization recommendation of this method as best practice for the control of malaria among infants. Manhiça's data can be accessed through a formal request to Diana Quelhas (diana.quelhas@manhica.net) accompanied by a proposal that will be analysed by the Manhiça HDSS internal scientific and ethics committees.
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Affiliation(s)
- Charfudin Sacoor
- Manhiça Health Research Centre, Manhiça District, Mozambique, Barcelona Centre for International Health Research, Hospital Clínic/Universitat de Barcelona, Spain, National Directorate of Health, Ministry of Health, Maputo, Mozambique, National Institute of Health, Ministry of Health, Maputo Mozambique and Faculty of Medicine, Eduardo Mondlane University, Maputo, Mozambique
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Singh K, Mehta S. The clinical development process for a novel preventive vaccine: An overview. J Postgrad Med 2016; 62:4-11. [PMID: 26732191 PMCID: PMC4944327 DOI: 10.4103/0022-3859.173187] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Each novel vaccine candidate needs to be evaluated for safety, immunogenicity, and protective efficacy in humans before it is licensed for use. After initial safety evaluation in healthy adults, each vaccine candidate follows a unique development path. This article on clinical development gives an overview on the development path based on the expectations of various guidelines issued by the World Health Organization (WHO), the European Medicines Agency (EMA), and the United States Food and Drug Administration (USFDA). The manuscript describes the objectives, study populations, study designs, study site, and outcome(s) of each phase (Phase I-III) of a clinical trial. Examples from the clinical development of a malaria vaccine candidate, a rotavirus vaccine, and two vaccines approved for human papillomavirus (HPV) have also been discussed. The article also tabulates relevant guidelines, which can be referred to while drafting the development path of a novel vaccine candidate.
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Affiliation(s)
- K Singh
- Malaria Vaccine Development Program (MVDP), International Centre for Genetic Engineering and Biotechnology (ICGEB) Campus, New Delhi, India
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40
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Abstract
Roly Gosling and Lorenz von Seidlein consider a potential future development plan for the RTS,S/AS01 malaria vaccine.
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MESH Headings
- Cost-Benefit Analysis
- Drug Approval
- Drug Costs
- Forecasting
- Health Expenditures/trends
- Humans
- Immunization Programs/economics
- Immunization Programs/trends
- Immunization Schedule
- Infant
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/adverse effects
- Malaria Vaccines/economics
- Malaria, Falciparum/diagnosis
- Malaria, Falciparum/economics
- Malaria, Falciparum/epidemiology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Patient Selection
- Plasmodium falciparum/immunology
- Social Change
- Time Factors
- Treatment Outcome
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/adverse effects
- Vaccines, Synthetic/economics
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Affiliation(s)
- Roly Gosling
- Global Health Group, University of California, San Francisco, San Francisco, California, United States of America
| | - Lorenz von Seidlein
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- * E-mail:
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Stassijns J, Bollaerts K, Baay M, Verstraeten T. A systematic review and meta-analysis on the safety of newly adjuvanted vaccines among children. Vaccine 2015; 34:714-22. [PMID: 26740250 DOI: 10.1016/j.vaccine.2015.12.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/08/2015] [Accepted: 12/10/2015] [Indexed: 12/15/2022]
Abstract
INTRODUCTION New adjuvants such as the AS- or the MF59-adjuvants improve vaccine efficacy and facilitate dose-sparing. Their use in influenza and malaria vaccines has resulted in a large body of evidence on their clinical safety in children. METHODS We carried out a systematic search for safety data from published clinical trials on newly adjuvanted vaccines in children ≤10 years of age. Serious adverse events (SAEs), solicited AEs, unsolicited AEs and AEs of special interest were evaluated for four new adjuvants: the immuno-stimulants containing adjuvant systems AS01 and AS02, and the squalene containing oil-in-water emulsions AS03 and MF59. Relative risks (RR) were calculated, comparing children receiving newly adjuvanted vaccines to children receiving other vaccines with a variety of antigens, both adjuvanted and unadjuvanted. RESULTS Twenty-nine trials were included in the meta-analysis, encompassing 25,056 children who received at least one dose of the newly adjuvanted vaccines. SAEs did not occur more frequently in adjuvanted groups (RR 0.85, 95%CI 0.75-0.96). Our meta-analyses showed higher reactogenicity following administration of newly adjuvanted vaccines, however, no consistent pattern of solicited AEs was observed across adjuvant systems. Pain was the most prevalent AE, but often mild and of short duration. No increased risks were found for unsolicited AEs, febrile convulsions, potential immune mediated diseases and new onset of chronic diseases. CONCLUSIONS Our meta-analysis did not show any safety concerns in clinical trials of the newly adjuvanted vaccines in children ≤10 years of age. An unexplained increase of meningitis in one Phase III AS01-adjuvanted malaria trial and the link between narcolepsy and the AS03-adjuvanted pandemic vaccine illustrate that continued safety monitoring is warranted.
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Affiliation(s)
- Jorgen Stassijns
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium
| | - Kaatje Bollaerts
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium
| | - Marc Baay
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium
| | - Thomas Verstraeten
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium.
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42
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Neafsey DE, Juraska M, Bedford T, Benkeser D, Valim C, Griggs A, Lievens M, Abdulla S, Adjei S, Agbenyega T, Agnandji ST, Aide P, Anderson S, Ansong D, Aponte JJ, Asante KP, Bejon P, Birkett AJ, Bruls M, Connolly KM, D'Alessandro U, Dobaño C, Gesase S, Greenwood B, Grimsby J, Tinto H, Hamel MJ, Hoffman I, Kamthunzi P, Kariuki S, Kremsner PG, Leach A, Lell B, Lennon NJ, Lusingu J, Marsh K, Martinson F, Molel JT, Moss EL, Njuguna P, Ockenhouse CF, Ogutu BR, Otieno W, Otieno L, Otieno K, Owusu-Agyei S, Park DJ, Pellé K, Robbins D, Russ C, Ryan EM, Sacarlal J, Sogoloff B, Sorgho H, Tanner M, Theander T, Valea I, Volkman SK, Yu Q, Lapierre D, Birren BW, Gilbert PB, Wirth DF. Genetic Diversity and Protective Efficacy of the RTS,S/AS01 Malaria Vaccine. N Engl J Med 2015; 373:2025-2037. [PMID: 26488565 PMCID: PMC4762279 DOI: 10.1056/nejmoa1505819] [Citation(s) in RCA: 273] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The RTS,S/AS01 vaccine targets the circumsporozoite protein of Plasmodium falciparum and has partial protective efficacy against clinical and severe malaria disease in infants and children. We investigated whether the vaccine efficacy was specific to certain parasite genotypes at the circumsporozoite protein locus. METHODS We used polymerase chain reaction-based next-generation sequencing of DNA extracted from samples from 4985 participants to survey circumsporozoite protein polymorphisms. We evaluated the effect that polymorphic positions and haplotypic regions within the circumsporozoite protein had on vaccine efficacy against first episodes of clinical malaria within 1 year after vaccination. RESULTS In the per-protocol group of 4577 RTS,S/AS01-vaccinated participants and 2335 control-vaccinated participants who were 5 to 17 months of age, the 1-year cumulative vaccine efficacy was 50.3% (95% confidence interval [CI], 34.6 to 62.3) against clinical malaria in which parasites matched the vaccine in the entire circumsporozoite protein C-terminal (139 infections), as compared with 33.4% (95% CI, 29.3 to 37.2) against mismatched malaria (1951 infections) (P=0.04 for differential vaccine efficacy). The vaccine efficacy based on the hazard ratio was 62.7% (95% CI, 51.6 to 71.3) against matched infections versus 54.2% (95% CI, 49.9 to 58.1) against mismatched infections (P=0.06). In the group of infants 6 to 12 weeks of age, there was no evidence of differential allele-specific vaccine efficacy. CONCLUSIONS These results suggest that among children 5 to 17 months of age, the RTS,S vaccine has greater activity against malaria parasites with the matched circumsporozoite protein allele than against mismatched malaria. The overall vaccine efficacy in this age category will depend on the proportion of matched alleles in the local parasite population; in this trial, less than 10% of parasites had matched alleles. (Funded by the National Institutes of Health and others.).
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43
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Agnandji ST, Fernandes JF, Bache EB, Ramharter M. Clinical development of RTS,S/AS malaria vaccine: a systematic review of clinical Phase I-III trials. Future Microbiol 2015; 10:1553-78. [PMID: 26437872 DOI: 10.2217/fmb.15.90] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The first clinical Phase III trial evaluating a malaria vaccine was completed in December 2013 at 11 sites from seven sub-Saharan African countries. This systematic review assesses data of Phase I-III trials including malaria-naive adults and adults, children and infants from malaria endemic settings in sub-Saharan Africa. The main endpoint of this systematic review was an analysis of the consistency of efficacy and immunogenicity data from respective Phase I-III trials. In addition, safety data from a pooled analysis of RTS/AS Phase II trials and RTS,S/AS01 Phase III trial were reviewed. The RTS,S/AS01 malaria vaccine may become available on the market in the coming year. If so, further strategies should address challenges on how to optimize vaccine efficacy and implementation of RTS,S/AS01 vaccine within the framework of established malaria control measures.
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Affiliation(s)
- Selidji T Agnandji
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon, Hôpital Albert Schweitzer BP 118, Lambaréné, Gabon.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Germany, Wilhelmstraße 27, 72074 Tübingen, Germany
| | - José F Fernandes
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon, Hôpital Albert Schweitzer BP 118, Lambaréné, Gabon.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Germany, Wilhelmstraße 27, 72074 Tübingen, Germany
| | - Emmanuel B Bache
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon, Hôpital Albert Schweitzer BP 118, Lambaréné, Gabon.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Germany, Wilhelmstraße 27, 72074 Tübingen, Germany
| | - Michael Ramharter
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon, Hôpital Albert Schweitzer BP 118, Lambaréné, Gabon.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Germany, Wilhelmstraße 27, 72074 Tübingen, Germany.,Department of Medicine I, Division of Infectious Diseases & Tropical Medicine, Medical University of Vienna, Austria, Währinger Gürtel 18-20, 1190 Vienna, Austria
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Abstract
Although recent control measures have significantly reduced malaria cases and deaths in many endemic areas, an effective vaccine will be essential to eradicate this parasitic disease. Malaria vaccine strategies developed to date focus on different phases of the parasite's complex life cycle in the human host and mosquito vector, and include both subunit-based and whole-parasite vaccines. This review focuses on the 3 live-attenuated malaria vaccination strategies that have been tested in humans to date, and discusses their progress, challenges and the immune correlates of protection that have been identified.
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Key Words
- CPS, Chemoprophylaxis and Sporozoite immunization
- CQ, chloroquine
- CSP, circumsporozoite protein
- GAP, Genetically Attenuated Parasite
- ITV, Immunization-Treatment-Vaccination
- Malaria
- P. falciparum
- PfSPZ, P. falciparum sporozoite vaccine
- RAS, Radiation Attenuated Sporozoites
- attenuation
- i.d., intradermal
- i.v., intravenous
- pre-erythrocytic
- s.c., subcutaneous
- whole-parasite vaccines
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45
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Penny MA, Galactionova K, Tarantino M, Tanner M, Smith TA. The public health impact of malaria vaccine RTS,S in malaria endemic Africa: country-specific predictions using 18 month follow-up Phase III data and simulation models. BMC Med 2015; 13:170. [PMID: 26219380 PMCID: PMC4518512 DOI: 10.1186/s12916-015-0408-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 06/25/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The RTS,S/AS01 malaria vaccine candidate recently completed Phase III trials in 11 African sites. Recommendations for its deployment will partly depend on predictions of public health impact in endemic countries. Previous predictions of these used only limited information on underlying vaccine properties and have not considered country-specific contextual data. METHODS Each Phase III trial cohort was simulated explicitly using an ensemble of individual-based stochastic models, and many hypothetical vaccine profiles. The true profile was estimated by Bayesian fitting of these models to the site- and time-specific incidence of clinical malaria in both trial arms over 18 months of follow-up. Health impacts of implementation via two vaccine schedules in 43 endemic sub-Saharan African countries, using country-specific prevalence, access to care, immunisation coverage and demography data, were predicted via weighted averaging over many simulations. RESULTS The efficacy against infection of three doses of vaccine was initially approximately 65 % (when immunising 6-12 week old infants) and 80 % (children 5-17 months old), with a 1 year half-life (exponential decay). Either schedule will avert substantial disease, but predicted impact strongly depends on the decay rate of vaccine effects and average transmission intensity. CONCLUSIONS For the first time Phase III site- and time-specific data were available to estimate both the underlying profile of RTS,S/AS01 and likely country-specific health impacts. Initial efficacy will probably be high, but decay rapidly. Adding RTS,S to existing control programs, assuming continuation of current levels of malaria exposure and of health system performance, will potentially avert 100-580 malaria deaths and 45,000 to 80,000 clinical episodes per 100,000 fully vaccinated children over an initial 10-year phase.
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Affiliation(s)
- Melissa A Penny
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Katya Galactionova
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Michael Tarantino
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Marcel Tanner
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| | - Thomas A Smith
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
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Tanner M, Greenwood B, Whitty CJM, Ansah EK, Price RN, Dondorp AM, von Seidlein L, Baird JK, Beeson JG, Fowkes FJI, Hemingway J, Marsh K, Osier F. Malaria eradication and elimination: views on how to translate a vision into reality. BMC Med 2015; 13:167. [PMID: 26208740 PMCID: PMC4514994 DOI: 10.1186/s12916-015-0384-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although global efforts in the past decade have halved the number of deaths due to malaria, there are still an estimated 219 million cases of malaria a year, causing more than half a million deaths. In this forum article, we asked experts working in malaria research and control to discuss the ways in which malaria might eventually be eradicated. Their collective views highlight the challenges and opportunities, and explain how multi-factorial and integrated processes could eventually make malaria eradication a reality.
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Affiliation(s)
- Marcel Tanner
- Swiss Tropical & Public Health Institute, 4002, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Christopher J M Whitty
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Evelyn K Ansah
- Research and Development Division, Ghana Health Service, Accra, Ghana.
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Arjen M Dondorp
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Lorenz von Seidlein
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - J Kevin Baird
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No.69, Jakarta, 10430, Indonesia.
| | - James G Beeson
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia. .,Department of Microbiology, Monash University, 19 Innovation Walk, Victoria, 3800, Australia.
| | - Freya J I Fowkes
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia. .,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia. .,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia. .,Department of Infectious Diseases, Monash University, Melbourne, Australia.
| | - Janet Hemingway
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Kevin Marsh
- African Academy of Sciences, Miotoni Road, Miotoni Lane, House No. 8 Karen, P.O. Box 24916-00502, Nairobi, Kenya.
| | - Faith Osier
- KEMRI Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.
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47
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Ockenhouse CF, Regules J, Tosh D, Cowden J, Kathcart A, Cummings J, Paolino K, Moon J, Komisar J, Kamau E, Oliver T, Chhoeu A, Murphy J, Lyke K, Laurens M, Birkett A, Lee C, Weltzin R, Wille-Reece U, Sedegah M, Hendriks J, Versteege I, Pau MG, Sadoff J, Vanloubbeeck Y, Lievens M, Heerwegh D, Moris P, Guerra Mendoza Y, Jongert E, Cohen J, Voss G, Ballou WR, Vekemans J. Ad35.CS.01-RTS,S/AS01 Heterologous Prime Boost Vaccine Efficacy against Sporozoite Challenge in Healthy Malaria-Naïve Adults. PLoS One 2015; 10:e0131571. [PMID: 26148007 PMCID: PMC4492580 DOI: 10.1371/journal.pone.0131571] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 06/02/2015] [Indexed: 12/19/2022] Open
Abstract
Methods In an observer blind, phase 2 trial, 55 adults were randomized to receive one dose of Ad35.CS.01 vaccine followed by two doses of RTS,S/AS01 (ARR-group) or three doses of RTS,S/AS01 (RRR-group) at months 0, 1, 2 followed by controlled human malaria infection. Results ARR and RRR vaccine regimens were well tolerated. Efficacy of ARR and RRR groups after controlled human malaria infection was 44% (95% confidence interval 21%-60%) and 52% (25%-70%), respectively. The RRR-group had greater anti-CS specific IgG titers than did the ARR-group. There were higher numbers of CS-specific CD4 T-cells expressing > 2 cytokine/activation markers and more ex vivo IFN-γ enzyme-linked immunospots in the ARR-group than the RRR-group. Protected subjects had higher CS-specific IgG titers than non-protected subjects (geometric mean titer, 120.8 vs 51.8 EU/ml, respectively; P = .001). Conclusions An increase in vaccine efficacy of ARR-group over RRR-group was not achieved. Future strategies to improve upon RTS,S-induced protection may need to utilize alternative highly immunogenic prime-boost regimens and/or additional target antigens. Trial Registration ClinicalTrials.gov NCT01366534
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Affiliation(s)
- Christian F. Ockenhouse
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
- * E-mail:
| | - Jason Regules
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Donna Tosh
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Jessica Cowden
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - April Kathcart
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - James Cummings
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Kristopher Paolino
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - James Moon
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Jack Komisar
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Edwin Kamau
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Thomas Oliver
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Austin Chhoeu
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Jitta Murphy
- Walter Reed Army Institute of Research, Silver Spring, MD, United States of America
| | - Kirsten Lyke
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Matthew Laurens
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | | | - Cynthia Lee
- PATH-MVI, Washington, DC, United States of America
| | - Rich Weltzin
- PATH-MVI, Washington, DC, United States of America
| | | | - Martha Sedegah
- Naval Medical Research Center, Silver Spring, MD, United States of America
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Whitacre DC, Espinosa DA, Peters CJ, Jones JE, Tucker AE, Peterson DL, Zavala FP, Milich DR. P. falciparum and P. vivax Epitope-Focused VLPs Elicit Sterile Immunity to Blood Stage Infections. PLoS One 2015; 10:e0124856. [PMID: 25933001 PMCID: PMC4416889 DOI: 10.1371/journal.pone.0124856] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/17/2015] [Indexed: 01/09/2023] Open
Abstract
In order to design P. falciparum preerythrocytic vaccine candidates, a library of circumsporozoite (CS) T and B cell epitopes displayed on the woodchuck hepatitis virus core antigen (WHcAg) VLP platform was produced. To test the protective efficacy of the WHcAg-CS VLPs, hybrid CS P. berghei/P. falciparum (Pb/Pf) sporozoites were used to challenge immunized mice. VLPs carrying 1 or 2 different CS repeat B cell epitopes and 3 VLPs carrying different CS non-repeat B cell epitopes elicited high levels of anti-insert antibodies (Abs). Whereas, VLPs carrying CS repeat B cell epitopes conferred 98% protection of the liver against a 10,000 Pb/Pf sporozoite challenge, VLPs carrying the CS non-repeat B cell eptiopes were minimally-to-non-protective. One-to-three CS-specific CD4/CD8 T cell sites were also fused to VLPs, which primed CS-specific as well as WHcAg-specific T cells. However, a VLP carrying only the 3 T cell domains failed to protect against a sporozoite challenge, indicating a requirement for anti-CS repeat Abs. A VLP carrying 2 CS repeat B cell epitopes and 3 CS T cell sites in alum adjuvant elicited high titer anti-CS Abs (endpoint dilution titer >1x106) and provided 80–100% protection against blood stage malaria. Using a similar strategy, VLPs were constructed carrying P. vivax CS repeat B cell epitopes (WHc-Pv-78), which elicited high levels of anti-CS Abs and conferred 99% protection of the liver against a 10,000 Pb/Pv sporozoite challenge and elicited sterile immunity to blood stage infection. These results indicate that immunization with epitope-focused VLPs carrying selected B and T cell epitopes from the P. falciparum and P. vivax CS proteins can elicit sterile immunity against blood stage malaria. Hybrid WHcAg-CS VLPs could provide the basis for a bivalent P. falciparum/P. vivax malaria vaccine.
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MESH Headings
- Animals
- Antibodies, Protozoan/immunology
- CD4-Positive T-Lymphocytes/immunology
- Epitopes, B-Lymphocyte/chemistry
- Epitopes, B-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/chemistry
- Epitopes, T-Lymphocyte/immunology
- Hepatitis B Virus, Woodchuck/immunology
- Immunity
- Immunization
- Life Cycle Stages
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Mice, Inbred C57BL
- Plasmodium falciparum/immunology
- Plasmodium vivax/immunology
- Protozoan Proteins/immunology
- Rabbits
- Repetitive Sequences, Amino Acid
- Reproducibility of Results
- Virion/immunology
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Affiliation(s)
- David C. Whitacre
- Vaccine Research Institute of San Diego, San Diego, California, United States of America
- VLP Biotech, Inc., San Diego, California, United States of America
| | - Diego A. Espinosa
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Cory J. Peters
- Vaccine Research Institute of San Diego, San Diego, California, United States of America
- VLP Biotech, Inc., San Diego, California, United States of America
| | - Joyce E. Jones
- Vaccine Research Institute of San Diego, San Diego, California, United States of America
- VLP Biotech, Inc., San Diego, California, United States of America
| | - Amy E. Tucker
- VLP Biotech, Inc., San Diego, California, United States of America
| | - Darrell L. Peterson
- Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Fidel P. Zavala
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - David R. Milich
- Vaccine Research Institute of San Diego, San Diego, California, United States of America
- VLP Biotech, Inc., San Diego, California, United States of America
- * E-mail:
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49
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Abstract
The development of a highly effective malaria vaccine remains a key goal to aid in the control and eventual eradication of this devastating parasitic disease. The field has made huge strides in recent years, with the first-generation vaccine RTS,S showing modest efficacy in a Phase III clinical trial. The updated 2030 Malaria Vaccine Technology Roadmap calls for a second generation vaccine to achieve 75% efficacy over two years for both Plasmodium falciparum and Plasmodium vivax, and for a vaccine that can prevent malaria transmission. Whole-parasite immunisation approaches and combinations of pre-erythrocytic subunit vaccines are now reporting high-level efficacy, whilst exciting new approaches to the development of blood-stage and transmission-blocking vaccine subunit components are entering clinical development. The development of a highly effective multi-component multi-stage subunit vaccine now appears to be a realistic ambition. This review will cover these recent developments in malaria vaccinology.
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50
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Local tolerance and systemic toxicity of single and repeated intramuscular administrations of two different formulations of the RTS,S malaria candidate vaccine in rabbits. Regul Toxicol Pharmacol 2015; 71:269-78. [DOI: 10.1016/j.yrtph.2014.12.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 12/01/2014] [Accepted: 12/19/2014] [Indexed: 11/22/2022]
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