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Ndawula C, Emudong P, Muwereza N, Currà C. Insights into Theileria transmission-blocking vaccines for East Coast fever control: A disease with an "outdated vaccination approach". Ticks Tick Borne Dis 2024; 15:102386. [PMID: 39128161 DOI: 10.1016/j.ttbdis.2024.102386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/25/2024] [Accepted: 07/29/2024] [Indexed: 08/13/2024]
Abstract
Instead of using the Infection and Treatment Method (ITM)-based vaccine, is it possible to control East Coast Fever (ECF) through blocking Theileria parva transmission in ticks and cattle? This review pursues this question. It's over 100 years since Arnold Theiler (1912) first illustrated the natural ITM as a vaccination approach against ECF-cattle disease. The approach entails infecting cattle with live Theileria sporozoites and co-treatment with long-acting tetracycline. Building on the ITM principle, the "Muguga"-cocktail ECF vaccine was developed in the 1970s and it remains the only commercially available-one. Although the vaccine induces cattle-protection, the vaccination approach still raises several drawbacks. Of those, the most outstanding is the vaccine-safety. This is implied because after ITM vaccination, cattle revert to T. parva pathogen reservoirs, therefore, during blood meal-acquisition, the ticks co-ingest T. parva pathogens. Ultimately, the pathogens are further transmitted transstadial; from larvae to nymph and nymph-adults and later re-transmitted to cattle during blood-meal acquisition. Consequently, the vaccine-constituting T. parva strains are introduced and (re) spread in non-endemic/ endemic areas. Precisely, rather than eradicating the disease, the ITM vaccination-approach promotes ECF endemicity. With advent of novel vaccination approaches toward vector and vector-borne disease control, ECF-control based on ITM of vaccination is considered outdated. The review highlights the need for embracing a holistic integrative vaccination approach entailing blocking Theileria pathogen-development and transmission both in the ticks and cattle, and/or the tick-population.
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Affiliation(s)
- C Ndawula
- National Agricultural Research Organization, P.O Box 295, Entebbe, Uganda; National Livestock Resources Research Institute, P.O Box 5704, Wakiso, Uganda.
| | - P Emudong
- National Agricultural Research Organization, P.O Box 295, Entebbe, Uganda; National Livestock Resources Research Institute, P.O Box 5704, Wakiso, Uganda
| | - N Muwereza
- National Agricultural Research Organization, P.O Box 295, Entebbe, Uganda; National Livestock Resources Research Institute, P.O Box 5704, Wakiso, Uganda
| | - C Currà
- Unit of Foodborne and Neglected Parasitic Diseases, Department of Infectious Diseases, ISTITUTO SUPERIORE di SANITÀ, Viale Regina Elena 299, 00161 Rome, Italy
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2
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Takashima E, Otsuki H, Morita M, Ito D, Nagaoka H, Yuguchi T, Hassan I, Tsuboi T. The Need for Novel Asexual Blood-Stage Malaria Vaccine Candidates for Plasmodium falciparum. Biomolecules 2024; 14:100. [PMID: 38254700 PMCID: PMC10813614 DOI: 10.3390/biom14010100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/25/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Extensive control efforts have significantly reduced malaria cases and deaths over the past two decades, but in recent years, coupled with the COVID-19 pandemic, success has stalled. The WHO has urged the implementation of a number of interventions, including vaccines. The modestly effective RTS,S/AS01 pre-erythrocytic vaccine has been recommended by the WHO for use in sub-Saharan Africa against Plasmodium falciparum in children residing in moderate to high malaria transmission regions. A second pre-erythrocytic vaccine, R21/Matrix-M, was also recommended by the WHO on 3 October 2023. However, the paucity and limitations of pre-erythrocytic vaccines highlight the need for asexual blood-stage malaria vaccines that prevent disease caused by blood-stage parasites. Few asexual blood-stage vaccine candidates have reached phase 2 clinical development, and the challenges in terms of their efficacy include antigen polymorphisms and low immunogenicity in humans. This review summarizes the history and progress of asexual blood-stage malaria vaccine development, highlighting the need for novel candidate vaccine antigens/molecules.
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Affiliation(s)
- Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Hitoshi Otsuki
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (H.O.); (D.I.)
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Daisuke Ito
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (H.O.); (D.I.)
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Takaaki Yuguchi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Ifra Hassan
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Takafumi Tsuboi
- Division of Cell-Free Sciences, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan
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3
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Falsafi M, Delirezh N, Safarzadeh E, Talebi A, Heidari Z. Irradiated oocysts in combination with inulin adjuvant-induced potent immune responses against Eimeria tenella infection in broiler chickens. VETERINARY RESEARCH FORUM : AN INTERNATIONAL QUARTERLY JOURNAL 2023; 14:423-429. [PMID: 37667788 PMCID: PMC10475167 DOI: 10.30466/vrf.2023.563143.3675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/06/2023] [Indexed: 09/06/2023]
Abstract
Coccidiosis is the leading parasitic disease in poultry. One of the most critical Eimeria species, Eimeria tenella, lives inside the cecal epithelial cells and induces bloody coccidiosis. The present study evaluated the effect of radiation-attenuated E. tenella oocytes mixed with inulin adjuvant on broiler chicken. Initially, the effect of irradiation on oocyst attenuation was confirmed. Then, one-day-old broilers (n = 90) were divided into nine groups on seven days of age as follow: Group 1 (400 attenuated oocysts + 1.00 mg of adjuvant), group 2 (400 attenuated oocysts + 0.50 mg adjuvant), group 3 (200 attenuated oocysts + 1.00 mg of adjuvant), group 4 (200 attenuated oocysts + 0.50 mg adjuvant), group 5 (1.00 mg adjuvant), group 6 (400 attenuated oocysts), group 7 (commercial vaccine), group 8 (negative control) and group 9 (blank). On day 21, we performed a challenge with E. tenella oocytes and investigated oocyst output and average weekly weight throughout the study. At the end of the study, we evaluated macroscopic lesion, histology, cytokine level and leukogram status. The results showed a statistically significant difference among groups. Furthermore, the optimal dose was 400 irradiated oocysts and 1.00 mg of inulin. Moreover, an X-ray could reduce the virulence of E. tenella oocytes. Inulin alone or combined with attenuated oocysts showed an acceptable effect on evaluated parameters.
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Affiliation(s)
- Monireh Falsafi
- Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran;
| | - Nowruz Delirezh
- Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran;
| | - Elham Safarzadeh
- Department of Medical Microbiology, Parasitology and Immunology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran;
| | - Alireza Talebi
- Department of Poultry Health and Diseases, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
| | - Zahra Heidari
- Department of Medical Microbiology, Parasitology and Immunology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran;
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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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5
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Zolfaghari Emameh R, Barker HR, Turpeinen H, Parkkila S, Hytönen VP. A reverse vaccinology approach on transmembrane carbonic anhydrases from Plasmodium species as vaccine candidates for malaria prevention. Malar J 2022; 21:189. [PMID: 35706028 PMCID: PMC9199335 DOI: 10.1186/s12936-022-04186-7] [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: 11/20/2021] [Accepted: 05/19/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is a significant parasitic infection, and human infection is mediated by mosquito (Anopheles) biting and subsequent transmission of protozoa (Plasmodium) to the blood. Carbonic anhydrases (CAs) are known to be highly expressed in the midgut and ectoperitrophic space of Anopheles gambiae. Transmembrane CAs (tmCAs) in Plasmodium may be potential vaccine candidates for the control and prevention of malaria. METHODS In this study, two groups of transmembrane CAs, including α-CAs and one group of η-CAs were analysed by immunoinformatics and computational biology methods, such as predictions on transmembrane localization of CAs from Plasmodium spp., affinity and stability of different HLA classes, antigenicity of tmCA peptides, epitope and proteasomal cleavage of Plasmodium tmCAs, accessibility of Plasmodium tmCAs MHC-ligands, allergenicity of Plasmodium tmCAs, disulfide-bond of Plasmodium tmCAs, B cell epitopes of Plasmodium tmCAs, and Cell type-specific expression of Plasmodium CAs. RESULTS Two groups of α-CAs and one group of η-CAs in Plasmodium spp. were identified to contain tmCA sequences, having high affinity towards MHCs, high stability, and strong antigenicity. All putative tmCAs were predicted to contain sequences for proteasomal cleavage in antigen presenting cells (APCs). CONCLUSIONS The predicted results revealed that tmCAs from Plasmodium spp. can be potential targets for vaccination against malaria.
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Affiliation(s)
- Reza Zolfaghari Emameh
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), 14965/161, Tehran, Iran.
| | - Harlan R Barker
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | | | - Seppo Parkkila
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Fimlab Laboratories Ltd and Tampere University Hospital, Tampere, Finland
| | - Vesa P Hytönen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Fimlab Laboratories Ltd and Tampere University Hospital, Tampere, Finland
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6
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Live attenuated vaccines, a favorable strategy to provide long-term immunity against protozoan diseases. Trends Parasitol 2021; 38:316-334. [PMID: 34896016 DOI: 10.1016/j.pt.2021.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 12/25/2022]
Abstract
The control of diseases caused by protozoan parasites is one of the United Nations' Sustainable Development Goals. In recent years much research effort has gone into developing a new generation of live attenuated vaccines (LAVs) against malaria, Chagas disease and leishmaniasis. However, there is a bottleneck related to their biosafety, production, and distribution that slows downs further development. The success of irradiated or genetically attenuated sporozoites against malaria, added to the first LAV against leishmaniasis to be evaluated in clinical trials, is indicative that the drawbacks of LAVs are gradually being overcome. However, whether persistence of LAVs is a prerequisite for sustained long-term immunity remains to be clarified, and the procedures necessary for clinical evaluation of vaccine candidates need to be standardized.
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7
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Duffy PE, Patrick Gorres J. Malaria vaccines since 2000: progress, priorities, products. NPJ Vaccines 2020; 5:48. [PMID: 32566259 PMCID: PMC7283239 DOI: 10.1038/s41541-020-0196-3] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/14/2020] [Indexed: 02/07/2023] Open
Abstract
Malaria vaccine development entered a new era in 2015 when the pre-erythrocytic Plasmodium falciparum candidate RTS,S was favorably reviewed by the European Medicines Agency and subsequently introduced into national pilot implementation programs, marking the first human anti-parasite vaccine to pass regulatory scrutiny. Since the first trials published in 1997, RTS,S has been evaluated in a series of clinical trials culminating in Phase 3 testing, while testing of other pre-erythrocytic candidates (that target sporozoite- or liver-stage parasites), particularly whole sporozoite vaccines, has also increased. Interest in blood-stage candidates (that limit blood-stage parasite growth) subsided after disappointing human efficacy results, although new blood-stage targets and concepts may revive activity in this area. Over the past decade, testing of transmission-blocking vaccines (that kill mosquito/sexual-stage parasites) advanced to field trials and the first generation of placental malaria vaccines (that clear placenta-sequestering parasites) entered the clinic. Novel antigen discovery, human monoclonal antibodies, structural vaccinology, and improved platforms promise to expand on RTS,S and improve existing vaccine candidates.
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Affiliation(s)
- Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - J. Patrick Gorres
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
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8
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Briquet S, Lawson-Hogban N, Peronet R, Mécheri S, Vaquero C. A genetically hmgb2 attenuated blood stage P. berghei induces crossed-long live protection. PLoS One 2020; 15:e0232183. [PMID: 32379764 PMCID: PMC7205229 DOI: 10.1371/journal.pone.0232183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/08/2020] [Indexed: 01/16/2023] Open
Abstract
Due to the lack of efficiency to control malaria elicited by sub-unit vaccine preparations, vaccination with live-attenuated Plasmodium parasite as reported 70 years ago with irradiated sporozoites regained recently a significant interest. The complex life cycle of the parasite and the different stages of development between mammal host and anopheles do not help to propose an easy vaccine strategy. In order to achieve a complete long-lasting protection against Plasmodium infection and disease, we considered a genetically attenuated blood stage parasite in the hmgb2 gene coding for the high-mobility-group-box 2 (HMGB2). This Plasmodium protein belongs to the HMGB family and hold as the mammal proteins, a double life since it acts first as a nuclear factor involved in chromatin remodelling and transcription regulation and second, when secreted as an active pro-inflammatory alarmin protein. Even though the number of reports on whole living attenuated blood stage parasites is limited when compared to attenuated sporozoites, the results reported with Plasmodium KO parasites are very encouraging. In this report, we present a novel strategy based on pre-immunization with Δhmgb2PbNK65 parasitized red blood cells that confer long-lasting protection in a murine experimental cerebral malaria model against two highly pathogenic homologous and heterologous parasites.
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Affiliation(s)
- Sylvie Briquet
- Sorbonne Université, Centre d’Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
- INSERM, U1135, CIMI-Paris, Paris, France
- CNRS, ERL 8255, CIMI-Paris, Paris, France
| | - Nadou Lawson-Hogban
- Sorbonne Université, Centre d’Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
- INSERM, U1135, CIMI-Paris, Paris, France
- CNRS, ERL 8255, CIMI-Paris, Paris, France
| | - Roger Peronet
- Unité de Biologie et Génétique du Paludisme, Institut Pasteur, Paris, France
- Centre National de Recherche Scientifique ou CNRS, Unité de Recherche Associée 2581, Paris, France
| | - Salaheddine Mécheri
- Unité de Biologie et Génétique du Paludisme, Institut Pasteur, Paris, France
- Centre National de Recherche Scientifique ou CNRS, Unité de Recherche Associée 2581, Paris, France
| | - Catherine Vaquero
- Sorbonne Université, Centre d’Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, France
- INSERM, U1135, CIMI-Paris, Paris, France
- CNRS, ERL 8255, CIMI-Paris, Paris, France
- * E-mail:
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Fu Y, Lu X, Zhu F, Zhao Y, Ding Y, Ye L, Guo B, Liu T, Xu W. Improving the immunogenicity and protective efficacy of a whole-killed malaria blood-stage vaccine by chloroquine. Parasite Immunol 2019; 42:e12682. [PMID: 31644820 DOI: 10.1111/pim.12682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/12/2019] [Accepted: 10/21/2019] [Indexed: 12/15/2022]
Abstract
A whole-killed malaria blood-stage vaccine (WKV) is promising in reducing the morbidity and mortality of malaria patients, but its efficacy needs to be improved. We found that the antimalarial drug chloroquine could augment the protective efficacy of the WKV of Plasmodium yoelii. The direct antimalarial effect of chloroquine on parasites during immunization could be excluded, as the administration of chloroquine or chloroquine plus alum every two weeks had a slight effect on parasitemia, and an immunization with NP-KLH (4-hydroxy-3-nitrophenylacetyl Keyhole Limpet Hemocyanin) plus chloroquine could significantly promote the generation of NP-specific antibodies. Additionally, alum was required for chloroquine to augment the immunogenicity of the pRBC lysate. Chloroquine did not promote the parasite-specific CD4+ T-cell responses, but significantly enhanced the WKV-induced germinal centre B cell reactions, class-switch recombination and secretion of functionally protective antibodies to plasmodium. The elevated parasite-specific antibodies were demonstrated to largely contribute to the chloroquine-enhanced protective immunity. Thus, we report that chloroquine could be used as an adjuvant to enhance the protective immunity of WKVs through promoting humoral responses.
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Affiliation(s)
- Yong Fu
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiao Lu
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Feng Zhu
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yunxiang Zhao
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yan Ding
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Lilin Ye
- Institute of Immunology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Bo Guo
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Taiping Liu
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Wenyue Xu
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, China
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Narula AK, Azad CS, Nainwal LM. New dimensions in the field of antimalarial research against malaria resurgence. Eur J Med Chem 2019; 181:111353. [DOI: 10.1016/j.ejmech.2019.05.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/16/2019] [Accepted: 05/15/2019] [Indexed: 12/20/2022]
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11
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Goh YS, McGuire D, Rénia L. Vaccination With Sporozoites: Models and Correlates of Protection. Front Immunol 2019; 10:1227. [PMID: 31231377 PMCID: PMC6560154 DOI: 10.3389/fimmu.2019.01227] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 05/14/2019] [Indexed: 12/14/2022] Open
Abstract
Despite continuous efforts, the century-old goal of eradicating malaria still remains. Multiple control interventions need to be in place simultaneously to achieve this goal. In addition to effective control measures, drug therapies and insecticides, vaccines are critical to reduce mortality and morbidity. Hence, there are numerous studies investigating various malaria vaccine candidates. Most of the malaria vaccine candidates are subunit vaccines. However, they have shown limited efficacy in Phase II and III studies. To date, only whole parasite formulations have been shown to induce sterile immunity in human. In this article, we review and discuss the recent developments in vaccination with sporozoites and the mechanisms of protection involved.
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Affiliation(s)
- Yun Shan Goh
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore
| | - Daniel McGuire
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Laurent Rénia
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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12
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Abstract
The development of highly effective and durable vaccines against the human malaria parasites Plasmodium falciparum and P. vivax remains a key priority. Decades of endeavor have taught that achieving this goal will be challenging; however, recent innovation in malaria vaccine research and a diverse pipeline of novel vaccine candidates for clinical assessment provides optimism. With first-generation pre-erythrocytic vaccines aiming for licensure in the coming years, it is important to reflect on how next-generation approaches can improve on their success. Here we review the latest vaccine approaches that seek to prevent malaria infection, disease, and transmission and highlight some of the major underlying immunological and molecular mechanisms of protection. The synthesis of rational antigen selection, immunogen design, and immunization strategies to induce quantitatively and qualitatively improved immune effector mechanisms offers promise for achieving sustained high-level protection.
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13
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Reiman JM, Kumar S, Rodriguez IB, Gnidehou S, Ito K, Stanisic DI, Lee M, McPhun V, Majam V, Willemsen NM, Batzloff MR, Raja AI, Dooley B, Hoffman SL, Yanow SK, Good MF. Induction of immunity following vaccination with a chemically attenuated malaria vaccine correlates with persistent antigenic stimulation. Clin Transl Immunology 2018; 7:e1015. [PMID: 29670745 PMCID: PMC5894007 DOI: 10.1002/cti2.1015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 12/12/2022] Open
Abstract
Objectives Blood stage malaria parasites attenuated with seco-cyclopropyl pyrrolo indole (CPI) analogues induce robust immunity in mice to homologous and heterologous malaria parasites and are being considered for the development of a human vaccine. However, it is not understood how attenuated parasites induce immunity. We showed that following vaccination, parasite DNA persisted in blood for several months, raising the possibility that ongoing immune stimulation may be critical. However, parasites were not seen microscopically beyond 24 h postvaccination. We aimed to provide a mechanistic understanding of immune induction. Methods Mice were vaccinated with chemically attenuated Plasmodium chabaudi parasites. PCR and adoptive transfer studies were used to determine the presence of parasites and antigen in vivo. In other experiments, Plasmodium falciparum parasitised red blood cells were attenuated in vitro and RNA and antigen expression studied. Results We show that blood transferred from vaccinated mice into naïve mice activates T cells and induces complete protective immunity in the recipient mice strongly suggesting that there is persistence of parasite antigen postvaccination. This is supported by the presence of parasite RNA in vaccinated mice and both RNA and antigen expression in P. falciparum cultures treated with CPI drugs in vitro. In addition, drugs that block parasite growth also prevent the induction of immunity in vaccinated mice, indicating that some growth of attenuated parasites is required for immune induction. Conclusions Attenuated parasites persist at submicroscopic levels in the blood of mice postvaccination with the ability to activate T cells and induce ongoing protective immune responses.
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Affiliation(s)
- Jennifer M Reiman
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Sanjai Kumar
- Laboratory of Emerging Pathogens Division of Emerging and Transfusion Transmitted Diseases CBER, FDA Rockville MD USA
| | | | | | - Koichi Ito
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | | | - Moses Lee
- Georgia State University Atlanta GA USA
| | - Virginia McPhun
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Victoria Majam
- Laboratory of Emerging Pathogens Division of Emerging and Transfusion Transmitted Diseases CBER, FDA Rockville MD USA
| | | | | | - Amber I Raja
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | - Brad Dooley
- Institute for Glycomics Griffith University Gold Coast QLD Australia
| | | | | | - Michael F Good
- Institute for Glycomics Griffith University Gold Coast QLD Australia
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14
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A whole parasite transmission-blocking vaccine for malaria: an ignored strategy. Emerg Top Life Sci 2017; 1:547-552. [PMID: 33525845 PMCID: PMC7289001 DOI: 10.1042/etls20170117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/24/2017] [Accepted: 10/31/2017] [Indexed: 12/05/2022]
Abstract
Malaria vaccine approaches can be divided into ‘subunit’ and ‘whole parasite’, and these can be directed at the sporozoite, liver stage, asexual or sexual stages. All combinations of approach and stage are under development with the exception of a whole parasite sexual stage (gametocyte) vaccine. A gametocyte vaccine would aim primarily to block transmission of malaria from the human host to the mosquito vector and as such is referred to as a ‘transmission-blocking vaccine’. An immunological feature of whole parasite vaccines for the sporozoite/liver stage and for the asexual blood stage is the reliance on cellular immunity involving T-cells to control parasite growth. T-cells can also respond vigorously to gametocytes and kill them in the vertebrate host and/or arrest their development. To date, cellular immunity has not been exploited in transmission-blocking vaccine development. Here, the data supporting a gametocyte whole parasite vaccine are reviewed and a strategy for vaccine development and testing is outlined.
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Coelho CH, Doritchamou JYA, Zaidi I, Duffy PE. Advances in malaria vaccine development: report from the 2017 malaria vaccine symposium. NPJ Vaccines 2017. [PMID: 29522056 PMCID: PMC5709382 DOI: 10.1038/s41541-017-0035-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Malaria Vaccine Symposium occurred at Johns Hopkins University in Baltimore, MD, USA on April 25th, 2017, coinciding with World Malaria Day and the WHO announcement that the RTS,S malaria vaccine would begin pilot implementation programs in Ghana, Kenya, and Malawi in 2018. Scientists from several disciplines reported progress on an array of malaria vaccine concepts and product candidates, including pre-erythrocytic vaccines that prevent infection, blood-stage vaccines that limit infection and disease, and transmission-blocking vaccines that interrupt the spread of infection. Other speakers highlighted the immunological and genetic considerations that must be addressed by vaccinologists to yield the most efficacious vaccines. Here, we highlight the advances in malaria vaccinology that were reported at the symposium.
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Affiliation(s)
- Camila Henriques Coelho
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Justin Yai Alamou Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Irfan Zaidi
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
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