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Nunes-Cabaço H, Moita D, Prudêncio M. Five decades of clinical assessment of whole-sporozoite malaria vaccines. Front Immunol 2022; 13:977472. [PMID: 36159849 PMCID: PMC9493004 DOI: 10.3389/fimmu.2022.977472] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
In 1967, pioneering work by Ruth Nussenzweig demonstrated for the first time that irradiated sporozoites of the rodent malaria parasite Plasmodium berghei protected mice against a challenge with infectious parasites of the same species. This remarkable finding opened up entirely new prospects of effective vaccination against malaria using attenuated sporozoites as immunization agents. The potential for whole-sporozoite-based immunization in humans was established in a clinical study in 1973, when a volunteer exposed to X-irradiated P. falciparum sporozoites was found to be protected against malaria following challenge with a homologous strain of this parasite. Nearly five decades later, much has been achieved in the field of whole-sporozoite malaria vaccination, and multiple reports on the clinical evaluation of such candidates have emerged. However, this process has known different paces before and after the turn of the century. While only a few clinical studies were published in the 1970’s, 1980’s and 1990’s, remarkable progress was made in the 2000’s and beyond. This article reviews the history of the clinical assessment of whole-sporozoite malaria vaccines over the last forty-nine years, highlighting the impressive achievements made over the last few years, and discussing some of the challenges ahead.
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Abstract
"The Primate Malarias" book has been a uniquely important resource for multiple generations of scientists, since its debut in 1971, and remains pertinent to the present day. Indeed, nonhuman primates (NHPs) have been instrumental for major breakthroughs in basic and pre-clinical research on malaria for over 50 years. Research involving NHPs have provided critical insights and data that have been essential for malaria research on many parasite species, drugs, vaccines, pathogenesis, and transmission, leading to improved clinical care and advancing research goals for malaria control, elimination, and eradication. Whilst most malaria scientists over the decades have been studying Plasmodium falciparum, with NHP infections, in clinical studies with humans, or using in vitro culture or rodent model systems, others have been dedicated to advancing research on Plasmodium vivax, as well as on phylogenetically related simian species, including Plasmodium cynomolgi, Plasmodium coatneyi, and Plasmodium knowlesi. In-depth study of these four phylogenetically related species over the years has spawned the design of NHP longitudinal infection strategies for gathering information about ongoing infections, which can be related to human infections. These Plasmodium-NHP infection model systems are reviewed here, with emphasis on modern systems biological approaches to studying longitudinal infections, pathogenesis, immunity, and vaccines. Recent discoveries capitalizing on NHP longitudinal infections include an advanced understanding of chronic infections, relapses, anaemia, and immune memory. With quickly emerging new technological advances, more in-depth research and mechanistic discoveries can be anticipated on these and additional critical topics, including hypnozoite biology, antigenic variation, gametocyte transmission, bone marrow dysfunction, and loss of uninfected RBCs. New strategies and insights published by the Malaria Host-Pathogen Interaction Center (MaHPIC) are recapped here along with a vision that stresses the importance of educating future experts well trained in utilizing NHP infection model systems for the pursuit of innovative, effective interventions against malaria.
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Affiliation(s)
- Mary R Galinski
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
- Emory Vaccine Center, Emory University, Atlanta, GA, USA.
- Emory National Primate Research Center (Yerkes National Primate Research Center), Emory University, Atlanta, GA, USA.
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Shibeshi W, Bagchus W, Yalkinoglu Ö, Tappert A, Engidawork E, Oeuvray C. Reproducibility of malaria sporozoite challenge model in humans for evaluating efficacy of vaccines and drugs: a systematic review. BMC Infect Dis 2021; 21:1274. [PMID: 34930178 PMCID: PMC8686662 DOI: 10.1186/s12879-021-06953-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/06/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The development of novel malaria vaccines and antimalarial drugs is limited partly by emerging challenges to conduct field trials in malaria endemic areas, including unknown effects of existing immunity and a reported fall in malaria incidence. As a result, Controlled Human Malaria Infection (CHMI) has become an important approach for accelerated development of malarial vaccines and drugs. We conducted a systematic review of the literature to establish aggregate evidence on the reproducibility of a malaria sporozoite challenge model. METHODS A systematic review of research articles published between 1990 and 2018 on efficacy testing of malaria vaccines and drugs using sporozoite challenge and sporozoite infectivity studies was conducted using Pubmed, Scopus, Embase and Cochrane Library, ClinicalTrials.gov and Trialtrove. The inclusion criteria were randomized and non-randomized, controlled or open-label trials using P. falciparum or P. vivax sporozoite challenges. The data were extracted from articles using standardized data extraction forms and descriptive analysis was performed for evidence synthesis. The endpoints considered were infectivity, prepatent period, parasitemia and safety of sporozoite challenge. RESULTS Seventy CHMI trials conducted with a total of 2329 adult healthy volunteers were used for analysis. CHMI was induced by bites of mosquitoes infected with P. falciparum or P. vivax in 52 trials and by direct venous inoculation of P. falciparum sporozoites (PfSPZ challenge) in 18 trials. Inoculation with P. falciparum-infected mosquitoes produced 100% infectivity in 40 studies and the mean/median prepatent period assessed by thick blood smear (TBS) microscopy was ≤ 12 days in 24 studies. On the other hand, out of 12 infectivity studies conducted using PfSPZ challenge, 100% infection rate was reproduced in 9 studies with a mean or median prepatent period of 11 to 15.3 days as assessed by TBS and 6.8 to 12.6 days by PCR. The safety profile of P. falciparum and P.vivax CHMI was characterized by consistent features of malaria infection. CONCLUSION There is ample evidence on consistency of P. falciparum CHMI models in terms of infectivity and safety endpoints, which supports applicability of CHMI in vaccine and drug development. PfSPZ challenge appears more feasible for African trials based on current evidence of safety and efficacy.
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Affiliation(s)
- Workineh Shibeshi
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
- Global Health Institute of Merck, Ares Trading S.A., A subsidiary of Merck KGaA, Darmstadt, Germany.
| | - Wilhelmina Bagchus
- Translational Medicine, Merck Serono S.A., An Affiliate of Merck KGaA, Darmstadt, Germany
| | - Özkan Yalkinoglu
- Translational Medicine, Merck Healthcare KGaA, Darmstadt, Germany
| | - Aliona Tappert
- Global Patient Safety, Merck Healthcare KGaA, Darmstadt, Germany
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Claude Oeuvray
- Global Health Institute of Merck, Ares Trading S.A., A subsidiary of Merck KGaA, Darmstadt, Germany
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Immunoprofiles associated with controlled human malaria infection and naturally acquired immunity identify a shared IgA pre-erythrocytic immunoproteome. NPJ Vaccines 2021; 6:115. [PMID: 34518543 PMCID: PMC8438027 DOI: 10.1038/s41541-021-00363-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 07/29/2021] [Indexed: 12/12/2022] Open
Abstract
Knowledge of the Plasmodium falciparum antigens that comprise the human liver stage immunoproteome is important for pre-erythrocytic vaccine development, but, compared with the erythrocytic stage immunoproteome, more challenging to classify. Previous studies of P. falciparum antibody responses report IgG and rarely IgA responses. We assessed IgG and IgA antibody responses in adult sera collected during two controlled human malaria infection (CHMI) studies in malaria-naïve volunteers and in 1- to 6-year-old malaria-exposed Malian children on a 251 P. falciparum antigen protein microarray. IgG profiles in the two CHMI groups were equivalent and differed from Malian children. IgA profiles were robust in the CHMI groups and a subset of Malian children. We describe immunoproteome differences in naïve vs. exposed individuals and report pre-erythrocytic proteins recognized by the immune system. IgA responses detected in this study expand the list of pre-erythrocytic antigens for further characterization as potential vaccine candidates.
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Chughlay MF, Akakpo S, Odedra A, Csermak-Renner K, Djeriou E, Winnips C, Leboulleux D, Gaur AH, Shanks GD, McCarthy J, Chalon S. Liver Enzyme Elevations in Plasmodium falciparum Volunteer Infection Studies: Findings and Recommendations. Am J Trop Med Hyg 2020; 103:378-393. [PMID: 32314694 PMCID: PMC7356411 DOI: 10.4269/ajtmh.19-0846] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Malaria volunteer infection studies (VISs) accelerate new drug and vaccine development. In the induced blood-stage malaria (IBSM) model, volunteers are inoculated with erythrocytes infected with Plasmodium falciparum. Observations of elevated liver enzymes in the IBSM model with new chemical entities (NCEs) promoted an analysis of available data. Data were reviewed from eight IBSM studies of seven different NCEs, plus two studies with the registered antimalarial piperaquine conducted between June 2013 and January 2017 at QIMR Berghofer, Brisbane, Australia. Alanine aminotransferase (ALT) was elevated (> 2.5 times the upper limit of normal [×ULN]) in 20/114 (17.5%) participants. Of these, 8.9% (10/114) had moderate increases (> 2.5–5 × ULN), noted in seven studies of six different NCEs ± piperaquine or piperaquine alone, and 8.9% (10/114) had severe elevations (> 5 × ULN), occurring in six studies of six different NCEs ± piperaquine. Aspartate aminotransferase (AST) was elevated (> 2.5 × ULN) in 11.4% (13/114) of participants, across six of the 10 studies. Bilirubin was > 2 × ULN in one participant. Published data from other VIS models, using sporozoite inoculation by systemic administration or mosquito feeding, also showed moderate/severe liver enzyme elevations. In conclusion, liver enzyme elevations in IBSM studies are most likely multifactorial and could be caused by the model conditions, that is, malaria infection/parasite density and/or effective parasite clearance, or by participant-specific risk factors, acetaminophen administration, or direct hepatotoxicity of the test drug. We make recommendations that may mitigate the risk of liver enzyme elevations in future VISs and propose measures to assist their interpretation, should they occur.
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Affiliation(s)
| | | | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | | | | | | | - Aditya H Gaur
- St. Jude Children's Research Hospital, Memphis, Tennessee
| | - G Dennis Shanks
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
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Seilie AM, Chang M, Hanron AE, Billman ZP, Stone BC, Zhou K, Olsen TM, Daza G, Ortega J, Cruz KR, Smith N, Healy SA, Neal J, Wallis CK, Shelton L, Mankowski TV, Wong-Madden S, Mikolajczak SA, Vaughan AM, Kappe SHI, Fishbaugher M, Betz W, Kennedy M, Hume JCC, Talley AK, Hoffman SL, Chakravarty S, Sim BKL, Richie TL, Wald A, Plowe CV, Lyke KE, Adams M, Fahle GA, Cowan EP, Duffy PE, Kublin JG, Murphy SC. Beyond Blood Smears: Qualification of Plasmodium 18S rRNA as a Biomarker for Controlled Human Malaria Infections. Am J Trop Med Hyg 2020; 100:1466-1476. [PMID: 31017084 PMCID: PMC6553913 DOI: 10.4269/ajtmh.19-0094] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
18S rRNA is a biomarker that provides an alternative to thick blood smears in controlled human malaria infection (CHMI) trials. We reviewed data from CHMI trials at non-endemic sites that used blood smears and Plasmodium 18S rRNA/rDNA biomarker nucleic acid tests (NATs) for time to positivity. We validated a multiplex quantitative reverse transcription–polymerase chain reaction (qRT-PCR) for Plasmodium 18S rRNA, prospectively compared blood smears and qRT-PCR for three trials, and modeled treatment effects at different biomarker-defined parasite densities to assess the impact on infection detection, symptom reduction, and measured intervention efficacy. Literature review demonstrated accelerated NAT-based infection detection compared with blood smears (mean acceleration: 3.2–3.6 days). For prospectively tested trials, the validated Plasmodium 18S rRNA qRT-PCR positivity was earlier (7.6 days; 95% CI: 7.1–8.1 days) than blood smears (11.0 days; 95% CI: 10.3–11.8 days) and significantly preceded the onset of grade 2 malaria-related symptoms (12.2 days; 95% CI: 10.6–13.3 days). Discrepant analysis showed that the risk of a blood smear–positive, biomarker-negative result was negligible. Data modeling predicted that treatment triggered by specific biomarker-defined thresholds can differentiate complete, partial, and non-protective outcomes and eliminate many grade 2 and most grade 3 malaria-related symptoms post-CHMI. Plasmodium 18S rRNA is a sensitive and specific biomarker that can justifiably replace blood smears for infection detection in CHMI trials in non-endemic settings. This study led to biomarker qualification through the U.S. Food and Drug Administration for use in CHMI studies at non-endemic sites, which will facilitate biomarker use for the qualified context of use in drug and vaccine trials.
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Affiliation(s)
- Annette M Seilie
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Ming Chang
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Amelia E Hanron
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Zachary P Billman
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Brad C Stone
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Kevin Zhou
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Tayla M Olsen
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Glenda Daza
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Jose Ortega
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Kurtis R Cruz
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Nahum Smith
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Sara A Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.,Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Washington, Seattle, Washington.,Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Jillian Neal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Carolyn K Wallis
- Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
| | - Lisa Shelton
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Tracie VonGoedert Mankowski
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Sharon Wong-Madden
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Sebastian A Mikolajczak
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Ashley M Vaughan
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Stefan H I Kappe
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Matt Fishbaugher
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Will Betz
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Mark Kennedy
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | - Jen C C Hume
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Angela K Talley
- Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington
| | | | | | | | | | - Anna Wald
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington
| | | | - Kirsten E Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Gary A Fahle
- Microbiology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | | | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - James G Kublin
- Seattle Malaria Clinical Trials Center, Fred Hutch Cancer Research Center, Seattle, Washington.,Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Sean C Murphy
- Department of Microbiology, University of Washington, Seattle, Washington.,Seattle Malaria Clinical Trials Center, Fred Hutch Cancer Research Center, Seattle, Washington.,Center for Global Infectious Disease Research, Seattle Children's Research Institute (formerly the Center for Infectious Disease Research), Seattle, Washington.,Department of Laboratory Medicine, Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington
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Sequeira J, Louçã J, Mendes AM, Lind PG. Transition from endemic behavior to eradication of malaria due to combined drug therapies: An agent-model approach. J Theor Biol 2019; 484:110030. [PMID: 31568789 DOI: 10.1016/j.jtbi.2019.110030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 09/14/2019] [Accepted: 09/26/2019] [Indexed: 01/05/2023]
Abstract
We introduce an agent-based model describing a susceptible-infectious-susceptible (SIS) system of humans and mosquitoes to predict malaria epidemiological scenarios in realistic biological conditions. Emphasis is given to the transition from endemic behavior to eradication of malaria transmission induced by combined drug therapies acting on both the gametocytemia reduction and on the selective mosquito mortality during parasite development in the mosquito. Our mathematical framework enables to uncover the critical values of the parameters characterizing the effect of each drug therapy. Moreover, our results provide quantitative evidence of what was up to now only partially assumed with empirical support: interventions combining gametocytemia reduction through the use of gametocidal drugs, with the selective action of ivermectin during parasite development in the mosquito, may actively promote disease eradication in the long run. In the agent model, the main properties of human-mosquito interactions are implemented as parameters and the model is validated by comparing simulations with real data of malaria incidence collected in the endemic malaria region of Chimoio in Mozambique. Finally, we discuss our findings in light of current drug administration strategies for malaria prevention, which may interfere with human-to-mosquito transmission process.
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Affiliation(s)
- João Sequeira
- Instituto Universitário de Lisboa (ISCTE-IUL), ISTAR-IUL, Av. das Forças Armadas, Lisboa 1649-026, Portugal; Hospital Santa Cruz, Av. Prof. Dr. Reinaldo dos Santos, Carnaxide 2790-134, Portugal
| | - Jorge Louçã
- Instituto Universitário de Lisboa (ISCTE-IUL), ISTAR-IUL, Av. das Forças Armadas, Lisboa 1649-026, Portugal
| | - António M Mendes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa 1649-028, Portugal
| | - Pedro G Lind
- Instituto Universitário de Lisboa (ISCTE-IUL), ISTAR-IUL, Av. das Forças Armadas, Lisboa 1649-026, Portugal; Department of Computer Science, OsloMet - Oslo Metropolitan University, P.O. Box 4 St. Olavs plass, Oslo N-0130, Norway.
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Friedman-Klabanoff DJ, Laurens MB, Berry AA, Travassos MA, Adams M, Strauss KA, Shrestha B, Levine MM, Edelman R, Lyke KE. The Controlled Human Malaria Infection Experience at the University of Maryland. Am J Trop Med Hyg 2019; 100:556-565. [PMID: 30675854 PMCID: PMC6402913 DOI: 10.4269/ajtmh.18-0476] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 12/03/2018] [Indexed: 11/07/2022] Open
Abstract
Controlled human malaria infection (CHMI) is a powerful tool to evaluate the efficacy of malaria vaccines and pharmacologics. Investigators at the University of Maryland, Baltimore, Center for Vaccine Development (UMB-CVD) pioneered the technique in the 1970s and continue to advance the frontiers of CHMI research. We reviewed the records of 338 malaria-naive volunteers who underwent CHMI at UMB-CVD with Plasmodium falciparum from 1971 until 2017. These 338 volunteers underwent 387 CHMI events, including 60 via intradermal injection or direct venous inoculation (DVI) of purified, cryopreserved sporozoites. No volunteer suffered an unplanned hospitalization or required intravenous therapy related to CHMI. Median prepatency period was longer in challenges using NF54 (9 days) than in those using 7G8 (8 days), P = 0.0006 by the log-rank test. With dose optimization of DVI, the prepatent period did not differ between DVI and mosquito bite challenge (log-rank test, P = 0.66). Polymerase chain reaction (PCR) detected P. falciparum infection 3 days earlier than thick smears (P < 0.001), and diagnosis by ultrasensitive PCR was associated with less severe symptoms than smear-based diagnosis (39% versus 0%, P = 0.0003). Historical studies with NF54 showed a shorter median prepatency period of 10.3 days than more recent studies (median 11.0 days, P = 0.02) despite significantly lower salivary gland scores in earlier studies, P = 0.0001. The 47-year experience of CHMI at UMB-CVD has led to advancements in sporozoite delivery, diagnostics, and use of heterologous challenge. Additional studies on new challenge strains and genomic data to reflect regional heterogeneity will help advance the use of CHMI as supporting data for vaccine licensure.
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Affiliation(s)
- DeAnna J. Friedman-Klabanoff
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea A. Berry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mark A. Travassos
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kathy A. Strauss
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Biraj Shrestha
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Myron M. Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert Edelman
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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Cooper MM, Loiseau C, McCarthy JS, Doolan DL. Human challenge models: tools to accelerate the development of malaria vaccines. Expert Rev Vaccines 2019; 18:241-251. [PMID: 30732492 DOI: 10.1080/14760584.2019.1580577] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Malaria challenge models, where healthy human volunteers are intentionally infected with Plasmodium species parasites under controlled conditions, can be undertaken in several well-defined ways. These challenge models enable evaluation of the kinetics of parasite growth and clearance, host-pathogen interactions and the host immune response. They can facilitate discovery of candidate diagnostic biomarkers and novel vaccine targets. As translational tools they can facilitate testing of candidate vaccines and drugs and evaluation of diagnostic tests. AREAS COVERED Until recently, malaria human challenge models have been limited to only a few Plasmodium falciparum strains and used exclusively in malaria-naïve volunteers in non-endemic regions. Several recent advances include the use of alternate P. falciparum strains and other species of Plasmodia, as well as strains attenuated by chemical, radiation or genetic modification, and the conduct of studies in pre-exposed individuals. Herein, we discuss how this diversification is enabling more thorough vaccine efficacy testing and informing rational vaccine development. EXPERT OPINION The ability to comprehensively evaluate vaccine efficacy in controlled settings will continue to accelerate the translation of candidate malaria vaccines to the clinic, and inform the development and optimisation of potential vaccines that would be effective against multiple strains in geographically and demographically diverse settings.
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Affiliation(s)
- Martha M Cooper
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - Claire Loiseau
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
| | - James S McCarthy
- b Infectious Diseases Programme , QIMR Berghofer Medical Research Institute , Brisbane , Australia
| | - Denise L Doolan
- a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia
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Taghavian O, Jain A, Joyner CJ, Ketchum S, Nakajima R, Jasinskas A, Liang L, Fong R, King C, Greenhouse B, Murphy M, Bailey J, Galinski MR, Barnwell JW, Plowe CV, Davies DH, Felgner PL. Antibody Profiling by Proteome Microarray with Multiplex Isotype Detection Reveals Overlap between Human and Aotus nancymaae Controlled Malaria Infections. Proteomics 2019; 18. [PMID: 29266845 DOI: 10.1002/pmic.201700277] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 11/21/2017] [Indexed: 12/13/2022]
Abstract
The development of vaccines against malaria and serodiagnostic tests for detecting recent exposure requires tools for antigen discovery and suitable animal models. The protein microarray is a high-throughput, sample sparing technique, with applications in infectious disease research, clinical diagnostics, epidemiology, and vaccine development. We recently demonstrated Qdot-based indirect immunofluorescence together with portable optical imager ArrayCAM using single isotype detection could replicate data using the conventional laser confocal scanner system. We developed a multiplexing protocol for simultaneous detection of IgG, IgA, and IgM and compared samples from a controlled human malaria infection model with those from controlled malaria infections of Aotus nancymaae, a widely used non-human primate model of human malaria. IgG profiles showed the highest concordance in number of reactive antigens; thus, of the 139 antigens recognized by human IgG antibody, 111 were also recognized by Aotus monkeys. Interestingly, IgA profiles were largely non-overlapping. Finally, on the path toward wider deployment of the portable platform, we show excellent correlations between array data obtained in five independent laboratories around the United States using the multiplexing protocol (R2 : 0.60-0.92). This study supports the use of this platform for wider deployment, particularly in endemic areas where such a tool will have the greatest impact on global human health.
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Affiliation(s)
- Omid Taghavian
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Aarti Jain
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Chester J Joyner
- International Center for Malaria Research, Education and Development, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | | | - Rie Nakajima
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Algis Jasinskas
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Li Liang
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Rich Fong
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Christopher King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Maxwell Murphy
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Jason Bailey
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, USA
| | - Mary R Galinski
- International Center for Malaria Research, Education and Development, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.,Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, USA
| | - John W Barnwell
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Christopher V Plowe
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA
| | - D Huw Davies
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
| | - Philip L Felgner
- Department of Medicine, Division of Infectious Diseases, University of California Irvine, Irvine, CA, USA
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11
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O'Brochta DA, Alford R, Harrell R, Aluvihare C, Eappen AG, Li T, Chakravarty S, Sim BKL, Hoffman SL, Billingsley PF. Is Saglin a mosquito salivary gland receptor for Plasmodium falciparum? Malar J 2019; 18:2. [PMID: 30602380 PMCID: PMC6317240 DOI: 10.1186/s12936-018-2634-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/20/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Saglin, a 100 kDa protein composed of two 50 kDa homodimers, is present in the salivary glands of Anopheles gambiae and has been considered an essential receptor for sporozoites (SPZ) of Plasmodium berghei and Plasmodium falciparum (Pf), allowing SPZ to recognize, bind to, and infect mosquito salivary glands. Spatial and temporal patterns of Saglin expression reported here, however, suggest that this model does not fully describe the Saglin-SPZ interaction. RESULTS Saglin protein was detected by indirect immunofluorescence microscopy only in the medial and proximal-lateral lobes, but not in the distal-lateral lobes, of the salivary glands of An. gambiae; the pattern of expression was independent of mosquito age or physiological state. These results were confirmed by steady-state Saglin transcript and protein expression using qRT-PCR and Western-blot analysis, respectively. Saglin was localized to the basal surface of the cells of the medial lobes and was undetectable elsewhere (intracellularly, on the lateral or apical membranes, the cells' secretory vacuoles, or in the salivary duct). In the cells of the proximal lateral lobes of the salivary glands, Saglin was distinctly intracellular and was not localized to any of the cell surfaces. Transgenic Anopheles stephensi were produced that expressed An. gambiae Saglin in the distal lateral lobes of the salivary gland. Additional Saglin expression did not enhance infection by PfSPZ compared to non-transgenic siblings fed on the same gametocyte-containing blood meal. CONCLUSIONS The absence of Saglin in the distal lateral lobes of the salivary glands, a primary destination for SPZ, suggests Saglin is not an essential receptor for Plasmodium SPZ. The lack of any correlation between increased Saglin expression in the distal lateral lobes of the salivary glands of transgenic An. stephensi and PfSPZ infection is also consistent with Saglin not being an essential salivary gland receptor for Plasmodium SPZ.
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Affiliation(s)
- David A O'Brochta
- Department of Entomology and The Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD, 20850, USA.,Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, North Bethesda, MD, 20852, USA
| | - Robert Alford
- Department of Entomology and The Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Robert Harrell
- University of Maryland Insect Transformation Facility, The Institute for Bioscience and Biotechnology Research, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Channa Aluvihare
- University of Maryland Insect Transformation Facility, The Institute for Bioscience and Biotechnology Research, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Abraham G Eappen
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Tao Li
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Sumana Chakravarty
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - B Kim Lee Sim
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Stephen L Hoffman
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA
| | - Peter F Billingsley
- Sanaria Inc., 9800 Medical Center Drive, Suite A209, Rockville, MD, 20850, USA.
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12
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Critical examination of approaches exploited to assess the effectiveness of transmission-blocking drugs for malaria. Future Med Chem 2018; 10:2619-2639. [PMID: 30499742 DOI: 10.4155/fmc-2018-0169] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the absence of clinically proven vaccines and emerging resistance to common antimalarials and insecticides, the onus of interrupting the life cycle of Plasmodium falciparum, is upon the transmission-blocking drugs. Current transmission-blocking drug primaquine finds its use restricted because of associated hemolytic toxicity issues in Glucose-6-Phosphate-Dehydrogenase deficient individuals. This article provides an extensive review of the assays used by the investigators to evaluate the transmission-blocking activity of drugs. Furthermore, limitations in existing transmission-blocking assessment approaches/studies are also covered in detail. This review is expected to help in the identification of lacunae in current understanding of transmission-blocking strategies, which are hindering our efforts to develop sustainable and effective transmission-blocking interventions.
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Abstract
Controlled human malaria infection (CHMI) entails deliberate infection with malaria parasites either by mosquito bite or by direct injection of sporozoites or parasitized erythrocytes. When required, the resulting blood-stage infection is curtailed by the administration of antimalarial drugs. Inducing a malaria infection via inoculation with infected blood was first used as a treatment (malariotherapy) for neurosyphilis in Europe and the United States in the early 1900s. More recently, CHMI has been applied to the fields of malaria vaccine and drug development, where it is used to evaluate products in well-controlled early-phase proof-of-concept clinical studies, thus facilitating progression of only the most promising candidates for further evaluation in areas where malaria is endemic. Controlled infections have also been used to immunize against malaria infection. Historically, CHMI studies have been restricted by the need for access to insectaries housing infected mosquitoes or suitable malaria-infected individuals. Evaluation of vaccine and drug candidates has been constrained in these studies by the availability of a limited number of Plasmodium falciparum isolates. Recent advances have included cryopreservation of sporozoites, the manufacture of well-characterized and genetically distinct cultured malaria cell banks for blood-stage infection, and the availability of Plasmodium vivax-specific reagents. These advances will help to accelerate malaria vaccine and drug development by making the reagents for CHMI more widely accessible and also enabling a more rigorous evaluation with multiple parasite strains and species. Here we discuss the different applications of CHMI, recent advances in the use of CHMI, and ongoing challenges for consideration.
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14
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Griffin P, Pasay C, Elliott S, Sekuloski S, Sikulu M, Hugo L, Khoury D, Cromer D, Davenport M, Sattabongkot J, Ivinson K, Ockenhouse C, McCarthy J. Safety and Reproducibility of a Clinical Trial System Using Induced Blood Stage Plasmodium vivax Infection and Its Potential as a Model to Evaluate Malaria Transmission. PLoS Negl Trop Dis 2016; 10:e0005139. [PMID: 27930652 PMCID: PMC5145139 DOI: 10.1371/journal.pntd.0005139] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 10/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Interventions to interrupt transmission of malaria from humans to mosquitoes represent an appealing approach to assist malaria elimination. A limitation has been the lack of systems to test the efficacy of such interventions before proceeding to efficacy trials in the field. We have previously demonstrated the feasibility of induced blood stage malaria (IBSM) infection with Plasmodium vivax. In this study, we report further validation of the IBSM model, and its evaluation for assessment of transmission of P. vivax to Anopheles stephensi mosquitoes. METHODS Six healthy subjects (three cohorts, n = 2 per cohort) were infected with P. vivax by inoculation with parasitized erythrocytes. Parasite growth was monitored by quantitative PCR, and gametocytemia by quantitative reverse transcriptase PCR (qRT-PCR) for the mRNA pvs25. Parasite multiplication rate (PMR) and size of inoculum were calculated by linear regression. Mosquito transmission studies were undertaken by direct and membrane feeding assays over 3 days prior to commencement of antimalarial treatment, and midguts of blood fed mosquitoes dissected and checked for presence of oocysts after 7-9 days. RESULTS The clinical course and parasitemia were consistent across cohorts, with all subjects developing mild to moderate symptoms of malaria. No serious adverse events were reported. Asymptomatic elevated liver function tests were detected in four of six subjects; these resolved without treatment. Direct feeding of mosquitoes was well tolerated. The estimated PMR was 9.9 fold per cycle. Low prevalence of mosquito infection was observed (1.8%; n = 32/1801) from both direct (4.5%; n = 20/411) and membrane (0.9%; n = 12/1360) feeds. CONCLUSION The P. vivax IBSM model proved safe and reliable. The clinical course and PMR were reproducible when compared with the previous study using this model. The IBSM model presented in this report shows promise as a system to test transmission-blocking interventions. Further work is required to validate transmission and increase its prevalence. TRIAL REGISTRATION Anzctr.org.au ACTRN12613001008718.
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Affiliation(s)
- Paul Griffin
- Clinical Tropical Medicine Laboratory, QIMR Berghofer, Brisbane, Australia
- Q-Pharm Pty Ltd, Brisbane, Australia
- Department of Medicine and Infectious Diseases, Mater Hospital and Mater Medical Research Institute, Brisbane, Australia
- The University of Queensland, Brisbane, Australia
| | - Cielo Pasay
- Clinical Tropical Medicine Laboratory, QIMR Berghofer, Brisbane, Australia
| | | | - Silvana Sekuloski
- Clinical Tropical Medicine Laboratory, QIMR Berghofer, Brisbane, Australia
| | - Maggy Sikulu
- Clinical Tropical Medicine Laboratory, QIMR Berghofer, Brisbane, Australia
| | - Leon Hugo
- Clinical Tropical Medicine Laboratory, QIMR Berghofer, Brisbane, Australia
| | - David Khoury
- University of New South Wales, Sydney, Australia
| | | | | | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Karen Ivinson
- PATH, Malaria Vaccine Initiative, Washington, DC, United States
| | | | - James McCarthy
- Clinical Tropical Medicine Laboratory, QIMR Berghofer, Brisbane, Australia
- The University of Queensland, Brisbane, Australia
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15
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Abstract
This article attempts to draw together current knowledge on the biology of Plasmodium and experience gained from past control campaigns to interpret and guide current efforts to discover and develop exciting new strategies targeting the parasite with the objective of interrupting transmission. Particular note is made of the advantages of targeting often unappreciated small, yet vital, bottleneck populations to enhance both the impact and the useful lifetime of hard-won interventions. A case is made for the standardization of methods to measure transmission blockade to permit the rational comparison of how diverse interventions (drugs, vaccines, insecticides, Genetically Modified technologies) targeting disparate aspects of parasite biology may impact upon the commonly used parameter of parasite prevalence in the human population.
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Affiliation(s)
- R E Sinden
- The Jenner Institute, Oxford, United Kingdom.
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16
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Billman ZP, Seilie AM, Murphy SC. Purification of Plasmodium Sporozoites Enhances Parasite-Specific CD8+ T Cell Responses. Infect Immun 2016; 84:2233-2242. [PMID: 27217420 PMCID: PMC4962643 DOI: 10.1128/iai.01439-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/14/2016] [Indexed: 01/26/2023] Open
Abstract
Malaria infection caused by Plasmodium parasites continues to cause enormous morbidity and mortality in areas where it is endemic, and there is no licensed vaccine capable of inducing sterile protection. Hyperimmunization with attenuated whole sporozoites can induce sterile protective immune responses targeting preerythrocytic antigens. Most animal models of hyperimmunization rely on sporozoites dissected from mosquito salivary glands and injected without further purification. In BALB/c mice, repeated small doses of P. yoelii sporozoites progressively expand the population of sporozoite-specific CD8(+) T cells. In this study, large secondary doses of unpurified sporozoites unexpectedly led to contraction of sporozoite-specific CD8(+) T cell responses in sporozoite-primed mice. While sporozoite-primed CD8(+) T cells alternatively can be expanded by secondary exposure to Listeria monocytogenes expressing recombinant Plasmodium antigens, such expansion was potently inhibited by coinjection of large doses of unpurified sporozoites and by uninfected salivary glands alone. Purification of sporozoites away from mosquito salivary gland debris by density gradient centrifugation eliminated salivary gland-associated inhibition. Thus, the inhibitory effect appears to be due to exposure to uninfected mosquito salivary glands rather than sporozoites. To further assess the effect of salivary gland exposure on later sporozoite vaccinations, mice were immunized with uninfected salivary glands from a single mosquito. Compared to naive mice, salivary gland presensitization reduced subsequent liver burdens by 71%. These data show that a component(s) in mosquito salivary glands reduces liver infection, thereby limiting antigen dose and contributing to lower-magnitude T cell responses. These findings suggest that sporozoite immunogenicity studies be performed using purified sporozoites whenever feasible.
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Affiliation(s)
- Zachary P Billman
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, USA
| | - Annette M Seilie
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, USA
| | - Sean C Murphy
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
- Department of Microbiology, University of Washington, Seattle, Washington, USA
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle, Washington, USA
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17
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Skurnik D, Cywes-Bentley C, Pier GB. The exceptionally broad-based potential of active and passive vaccination targeting the conserved microbial surface polysaccharide PNAG. Expert Rev Vaccines 2016; 15:1041-53. [PMID: 26918288 PMCID: PMC4985264 DOI: 10.1586/14760584.2016.1159135] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/24/2016] [Indexed: 11/08/2022]
Abstract
A challenging component of vaccine development is the large serologic diversity of protective antigens. Remarkably, there is a conserved surface/capsular polysaccharide, one of the most effective vaccine targets, expressed by a large number of bacterial, fungal and eukaryotic pathogens: poly-N-acetyl glucosamine (PNAG). Natural antibodies to PNAG are poorly effective at mediating in vitro microbial killing or in vivo protection. Removing most of the acetate substituents to produce a deacetylated glycoform, or using synthetic oligosaccharides of poly-β-1-6-linked glucosamine conjugated to carrier proteins, results in vaccines that elicit high levels of broad-based immunity. A fully human monoclonal antibody is highly active in laboratory and preclinical studies and has been successfully tested in a phase-I setting. Both the synthetic oligosaccharide conjugate vaccine and MAb will be further tested in humans starting in 2016; but, even if effective against only a fraction of the PNAG-producing pathogens, a major advance in vaccine-preventable diseases will occur.
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Affiliation(s)
- David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
| | - Gerald B. Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Ave., Boston, MA 02115, Phone: 617-525-2269; FAX: 617-525-2510
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18
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Lyke KE, Laurens MB, Strauss K, Adams M, Billingsley PF, James E, Manoj A, Chakravarty S, Plowe CV, Li ML, Ruben A, Edelman R, Green M, Dube TJ, Kim Lee Sim B, Hoffman SL. Optimizing Intradermal Administration of Cryopreserved Plasmodium falciparum Sporozoites in Controlled Human Malaria Infection. Am J Trop Med Hyg 2015; 93:1274-1284. [PMID: 26416102 PMCID: PMC4674246 DOI: 10.4269/ajtmh.15-0341] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/30/2015] [Indexed: 01/06/2023] Open
Abstract
Controlled human malaria infection (CHMI) is a powerful tool to evaluate malaria vaccine and prophylactic drug efficacy. Until recently CHMI was only carried out by the bite of infected mosquitoes. A parenteral method of CHMI would standardize Plasmodium falciparum sporozoite (PfSPZ) administration, eliminate the need for expensive challenge facility infrastructure, and allow for use of many P. falciparum strains. Recently, intradermal (ID) injection of aseptic, purified, cryopreserved PfSPZ was shown to induce P. falciparum malaria; however, 100% infection rates were not achieved by ID injection. To optimize ID PfSPZ dosing so as to achieve 100% infection, 30 adults aged 18-45 years were randomized to one of six groups composed of five volunteers each. The parameters of dose (1 × 10(4) versus 5 × 10(4) PfSPZ total dose per volunteer), number of injections (two versus eight), and aliquot volume per ID injection (10 μL versus 50 μL) were studied. Three groups attained 100% infection: 1 × 10(4) PfSPZ in 50 μL/2 doses, 1 × 10(4) PfSPZ in 10 μL/2 doses, and 5 × 10(4) PfSPZ in 10 μL/8 doses. The group that received 5 × 10(4) PfSPZ total dose in eight 10 μL injections had a 100% infection rate and the shortest prepatent period (mean of 12.7 days), approaching the prepatent period for the current CHMI standard of five infected mosquitoes.
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Affiliation(s)
- Kirsten E. Lyke
- *Address correspondence to Kirsten E. Lyke, Center for Vaccine Development, University of Maryland School of Medicine, HSF I, Room 480, Baltimore, MD 21201. E-mail:
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19
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Gómez-Pérez GP, Legarda A, Muñoz J, Sim BKL, Ballester MR, Dobaño C, Moncunill G, Campo JJ, Cisteró P, Jimenez A, Barrios D, Mordmüller B, Pardos J, Navarro M, Zita CJ, Nhamuave CA, García-Basteiro AL, Sanz A, Aldea M, Manoj A, Gunasekera A, Billingsley PF, Aponte JJ, James ER, Guinovart C, Antonijoan RM, Kremsner PG, Hoffman SL, Alonso PL. Controlled human malaria infection by intramuscular and direct venous inoculation of cryopreserved Plasmodium falciparum sporozoites in malaria-naïve volunteers: effect of injection volume and dose on infectivity rates. Malar J 2015; 14:306. [PMID: 26245196 PMCID: PMC4527105 DOI: 10.1186/s12936-015-0817-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 07/22/2015] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Controlled human malaria infection (CHMI) by mosquito bite is a powerful tool for evaluation of vaccines and drugs against Plasmodium falciparum malaria. However, only a small number of research centres have the facilities required to perform such studies. CHMI by needle and syringe could help to accelerate the development of anti-malaria interventions by enabling centres worldwide to employ CHMI. METHODS An open-label CHMI study was performed with aseptic, purified, cryopreserved P. falciparum sporozoites (PfSPZ Challenge) in 36 malaria naïve volunteers. In part A, the effect of the inoculation volume was assessed: 18 participants were injected intramuscularly (IM) with a dose of 2,500 PfSPZ divided into two injections of 10 µL (n = 6), 50 µL (n = 6) or 250 µL (n = 6), respectively. In part B, the injection volume that resulted in highest infectivity rates in part A (10 µL) was used to formulate IM doses of 25,000 PfSPZ (n = 6) and 75,000 PfSPZ (n = 6) divided into two 10-µL injections. Results from a parallel trial led to the decision to add a positive control group (n = 6), each volunteer receiving 3,200 PfSPZ in a single 500-µL injection by direct venous inoculation (DVI). RESULTS Four/six participants in the 10-µL group, 1/6 in the 50-µL group and 2/6 in the 250-µL group developed parasitaemia. Geometric mean (GM) pre-patent periods were 13.9, 14.0 and 15.0 days, respectively. Six/six (100%) participants developed parasitaemia in the 25,000 and 75,000 PfSPZ IM and 3,200 PfSPZ DVI groups. GM pre-patent periods were 12.2, 11.4 and 11.4 days, respectively. Injection of PfSPZ Challenge was well tolerated and safe in all groups. CONCLUSIONS IM injection of 75,000 PfSPZ and DVI injection of 3,200 PfSPZ resulted in infection rates and pre-patent periods comparable to the bite of five PfSPZ-infected mosquitoes. Remarkably, it required 23.4-fold more PfSPZ administered IM than DVI to achieve the same parasite kinetics. These results allow for translation of CHMI from research to routine use, and inoculation of PfSPZ by IM and DVI regimens. TRIAL REGISTRATION ClinicalTrials.gov NCT01771848.
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Affiliation(s)
- Gloria P Gómez-Pérez
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
- Department of Infectious Diseases, Centre of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, PO Box 22660, 1100 DD, Amsterdam, The Netherlands.
| | - Almudena Legarda
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Jose Muñoz
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | | | - María Rosa Ballester
- Drug Research Centre (CIM), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
- Department of Pharmacology and Therapeutics, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.
| | - Carlota Dobaño
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Gemma Moncunill
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Joseph J Campo
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
- Antigen Discovery, Inc, Irvine, CA, USA.
| | - Pau Cisteró
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Alfons Jimenez
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Diana Barrios
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Centre for Infection Research, 72074, Tübingen, Germany.
| | - Josefina Pardos
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Mireia Navarro
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | | | | | - Alberto L García-Basteiro
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
| | - Ariadna Sanz
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Marta Aldea
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
| | | | | | | | - John J Aponte
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | | | - Caterina Guinovart
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
| | - Rosa M Antonijoan
- Drug Research Centre (CIM), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
- Department of Pharmacology and Therapeutics, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.
| | - Peter G Kremsner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Centre for Infection Research, 72074, Tübingen, Germany.
| | | | - Pedro L Alonso
- ISGlobal, Barcelona Ctr Int Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
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Seo HS. Application of radiation technology in vaccines development. Clin Exp Vaccine Res 2015; 4:145-58. [PMID: 26273573 PMCID: PMC4524899 DOI: 10.7774/cevr.2015.4.2.145] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/10/2015] [Accepted: 06/20/2015] [Indexed: 12/11/2022] Open
Abstract
One of the earliest methods used in the manufacture of stable and safe vaccines is the use of chemical and physical treatments to produce inactivated forms of pathogens. Although these types of vaccines have been successful in eliciting specific humoral immune responses to pathogen-associated immunogens, there is a large demand for the development of fast, safe, and effective vaccine manufacturing strategies. Radiation sterilization has been used to develop a variety of vaccine types, because it can eradicate chemical contaminants and penetrate pathogens to destroy nucleic acids without damaging the pathogen surface antigens. Nevertheless, irradiated vaccines have not widely been used at an industrial level because of difficulties obtaining the necessary equipment. Recent successful clinical trials of irradiated vaccines against pathogens and tumors have led to a reevaluation of radiation technology as an alternative method to produce vaccines. In the present article, we review the challenges associated with creating irradiated vaccines and discuss potential strategies for developing vaccines using radiation technology.
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Affiliation(s)
- Ho Seong Seo
- Radiation Biotechnology Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
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21
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Moreno A, Joyner C. Malaria vaccine clinical trials: what's on the horizon. Curr Opin Immunol 2015; 35:98-106. [PMID: 26172291 DOI: 10.1016/j.coi.2015.06.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/12/2015] [Accepted: 06/22/2015] [Indexed: 01/01/2023]
Abstract
Significant progress toward a malaria vaccine, specifically for Plasmodium falciparum, has been made in the past few years with the completion of numerous clinical trials. Each trial has utilized a unique combination of antigens, delivery platforms, and adjuvants, which has provided the research community with a wealth of critical information to apply towards the development of next generation malaria vaccines. Despite the progress toward a P. falciparum vaccine, P. vivax vaccine research requires more momentum and additional investigations to identify novel vaccine candidates. In this review, recently completed and ongoing malaria vaccine clinical trials as well as vaccine candidates that are in the development pipeline are reviewed. Perspectives for future research using post-genomic mining, nonhuman primate models, and systems biology are also discussed.
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Affiliation(s)
- Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA; Malaria Host-Pathogen Interaction Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University, 69 Jesse Hill, Jr. Drive, SE, Atlanta, GA 30303, USA.
| | - Chester Joyner
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA; Malaria Host-Pathogen Interaction Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA
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22
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Li T, Eappen AG, Richman AM, Billingsley PF, Abebe Y, Li M, Padilla D, Rodriguez-Barraquer I, Sim BKL, Hoffman SL. Robust, reproducible, industrialized, standard membrane feeding assay for assessing the transmission blocking activity of vaccines and drugs against Plasmodium falciparum. Malar J 2015; 14:150. [PMID: 25890243 PMCID: PMC4491417 DOI: 10.1186/s12936-015-0665-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/24/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND A vaccine that interrupts malaria transmission (VIMT) would be a valuable tool for malaria control and elimination. One VIMT approach is to identify sexual erythrocytic and mosquito stage antigens of the malaria parasite that induce immune responses targeted at disrupting parasite development in the mosquito. The standard Plasmodium falciparum membrane-feeding assay (SMFA) is used to assess transmission-blocking activity (TBA) of antibodies against candidate immunogens and of drugs targeting the mosquito stages. To develop its P. falciparum sporozoite (SPZ) products, Sanaria has industrialized the production of P. falciparum-infected Anopheles stephensi mosquitoes, incorporating quantitative analyses of oocyst and P. falciparum SPZ infections as part of the manufacturing process. METHODS These capabilities were exploited to develop a robust, reliable, consistent SMFA that was used to assess 188 serum samples from animals immunized with the candidate vaccine immunogen, Pfs25, targeting P. falciparum mosquito stages. Seventy-four independent SMFAs were performed. Infection intensity (number of oocysts/mosquito) and infection prevalence (percentage of mosquitoes infected with oocysts) were compared between mosquitoes fed cultured gametocytes plus normal human O(+) serum (negative control), anti-Pfs25 polyclonal antisera (MRA39 or MRA38, at a final dilution in the blood meal of 1:54 as positive control), and test sera from animals immunized with Pfs25 (at a final dilution in the blood meal of 1:9). RESULTS SMFA negative controls consistently yielded high infection intensity (mean = 46.1 oocysts/midgut, range of positives 3.7-135.6) and infection prevalence (mean = 94.2%, range 71.4-100.0) and in positive controls, infection intensity was reduced by 81.6% (anti-Pfs25 MRA39) and 97.0% (anti-Pfs25 MRA38), and infection prevalence was reduced by 12.9 and 63.5%, respectively. A range of TBAs was detected among the 188 test samples assayed in duplicate. Consistent administration of infectious gametocytes to mosquitoes within and between assays was achieved, and the TBA of anti-Pfs25 control antibodies was highly reproducible. CONCLUSIONS These results demonstrate a robust capacity to perform the SMFA in a medium-to-high throughput format, suitable for assessing large numbers of experimental samples of candidate antibodies or drugs.
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Affiliation(s)
- Tao Li
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Abraham G Eappen
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Adam M Richman
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | | | - Yonas Abebe
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Minglin Li
- Protein Potential LLC, 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Debbie Padilla
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Isabel Rodriguez-Barraquer
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Suite E6003, Baltimore, MD, 21205, USA.
| | - B Kim Lee Sim
- Sanaria Inc., 9800 Medical Center Drive, Rockville, MD, 20850, USA.
- Protein Potential LLC, 9800 Medical Center Drive, Rockville, MD, 20850, USA.
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23
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Mordmüller B, Supan C, Sim KL, Gómez-Pérez GP, Ospina Salazar CL, Held J, Bolte S, Esen M, Tschan S, Joanny F, Lamsfus Calle C, Löhr SJZ, Lalremruata A, Gunasekera A, James ER, Billingsley PF, Richman A, Chakravarty S, Legarda A, Muñoz J, Antonijoan RM, Ballester MR, Hoffman SL, Alonso PL, Kremsner PG. Direct venous inoculation of Plasmodium falciparum sporozoites for controlled human malaria infection: a dose-finding trial in two centres. Malar J 2015; 14:117. [PMID: 25889522 PMCID: PMC4371633 DOI: 10.1186/s12936-015-0628-0] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 03/01/2015] [Indexed: 11/12/2022] Open
Abstract
Background Controlled human malaria infection (CHMI) accelerates development of anti-malarial interventions. So far, CHMI is done by exposure of volunteers to bites of five mosquitoes carrying Plasmodium falciparum sporozoites (PfSPZ), a technique available in only a few centres worldwide. Mosquito-mediated CHMI is logistically complex, exact PfSPZ dosage is impossible and live mosquito-based interventions are not suitable for further clinical development. Methods An open-labelled, randomized, dose-finding study in 18–45 year old, healthy, malaria-naïve volunteers was performed to assess if intravenous (IV) injection of 50 to 3,200 aseptic, purified, cryopreserved PfSPZ is safe and achieves infection kinetics comparable to published data of mosquito-mediated CHMI. An independent study site verified the fully infectious dose using direct venous inoculation of PfSPZ. Parasite kinetics were assessed by thick blood smear microscopy and quantitative real time PCR. Results IV inoculation with 50, 200, 800, or 3,200 PfSPZ led to parasitaemia in 1/3, 1/3, 7/9, and 9/9 volunteers, respectively. The geometric mean pre-patent period (GMPPP) was 11.2 days (range 10.5–12.5) in the 3,200 PfSPZ IV group. Subsequently, six volunteers received 3,200 PfSPZ by direct venous inoculation at an independent investigational site. All six developed parasitaemia (GMPPP: 11.4 days, range: 10.4–12.3). Inoculation of PfSPZ was safe. Infection rate and pre-patent period depended on dose, and injection of 3,200 PfSPZ led to a GMPPP similar to CHMI with five PfSPZ-infected mosquitoes. The infectious dose of PfSPZ predicted dosage of radiation-attenuated PfSPZ required for successful vaccination. Conclusions IV inoculation of PfSPZ is safe, well tolerated and highly reproducible. It shall further accelerate development of anti-malarial interventions through standardization and facilitation of CHMI. Beyond this, rational dose selection for whole PfSPZ-based immunization and complex study designs are now possible. Trial registration ClinicalTrials.gov NCT01624961 and NCT01771848.
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Affiliation(s)
- Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Christian Supan
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | | | - Gloria P Gómez-Pérez
- Barcelona Center for International Health Research (CRESIB), Hospital Clínic, University of Barcelona, E-08036, Barcelona, Spain.
| | - Carmen Lucelly Ospina Salazar
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Jana Held
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Stefanie Bolte
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Meral Esen
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Serena Tschan
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Fanny Joanny
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Carlos Lamsfus Calle
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Sascha J Z Löhr
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | - Albert Lalremruata
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
| | | | | | | | | | | | - Almudena Legarda
- Barcelona Center for International Health Research (CRESIB), Hospital Clínic, University of Barcelona, E-08036, Barcelona, Spain.
| | - Jose Muñoz
- Barcelona Center for International Health Research (CRESIB), Hospital Clínic, University of Barcelona, E-08036, Barcelona, Spain.
| | - Rosa M Antonijoan
- Drug Research Center (CIM), Institute of Biomedical Research (IIB), Research Institute of Santa Creu and Sant Pau Hospital, Barcelona, Spain. .,Department of Pharmacology and Therapeutics, Autonomous University of Barcelona (UAB), Santa Creu and Sant Pau Hospital, E-08026, Barcelona, Spain.
| | - Maria Rosa Ballester
- Drug Research Center (CIM), Institute of Biomedical Research (IIB), Research Institute of Santa Creu and Sant Pau Hospital, Barcelona, Spain. .,Department of Pharmacology and Therapeutics, Autonomous University of Barcelona (UAB), Santa Creu and Sant Pau Hospital, E-08026, Barcelona, Spain.
| | | | - Pedro L Alonso
- Barcelona Center for International Health Research (CRESIB), Hospital Clínic, University of Barcelona, E-08036, Barcelona, Spain.
| | - Peter G Kremsner
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen and German Center for Infection Research, 72074, Tübingen, Germany.
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24
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Shekalaghe S, Rutaihwa M, Billingsley PF, Chemba M, Daubenberger CA, James ER, Mpina M, Ali Juma O, Schindler T, Huber E, Gunasekera A, Manoj A, Simon B, Saverino E, Church LWP, Hermsen CC, Sauerwein RW, Plowe C, Venkatesan M, Sasi P, Lweno O, Mutani P, Hamad A, Mohammed A, Urassa A, Mzee T, Padilla D, Ruben A, Lee Sim BK, Tanner M, Abdulla S, Hoffman SL. Controlled human malaria infection of Tanzanians by intradermal injection of aseptic, purified, cryopreserved Plasmodium falciparum sporozoites. Am J Trop Med Hyg 2014; 91:471-480. [PMID: 25070995 PMCID: PMC4155546 DOI: 10.4269/ajtmh.14-0119] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Controlled human malaria infection (CHMI) by mosquito bite has been used to assess anti-malaria interventions in > 1,500 volunteers since development of methods for infecting mosquitoes by feeding on Plasmodium falciparum (Pf) gametocyte cultures. Such CHMIs have never been used in Africa. Aseptic, purified, cryopreserved Pf sporozoites, PfSPZ Challenge, were used to infect Dutch volunteers by intradermal injection. We conducted a double-blind, placebo-controlled trial to assess safety and infectivity of PfSPZ Challenge in adult male Tanzanians. Volunteers were injected intradermally with 10,000 (N = 12) or 25,000 (N = 12) PfSPZ or normal saline (N = 6). PfSPZ Challenge was well tolerated and safe. Eleven of 12 and 10 of 11 subjects, who received 10,000 and 25,000 PfSPZ respectively, developed parasitemia. In 10,000 versus 25,000 PfSPZ groups geometric mean days from injection to Pf positivity by thick blood film was 15.4 versus 13.5 (P = 0.023). Alpha-thalassemia heterozygosity had no apparent effect on infectivity. PfSPZ Challenge was safe, well tolerated, and infectious.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Stephen L. Hoffman
- *Address correspondence to Stephen L. Hoffman, Sanaria Inc., 9800 Medical Center Drive, Rockville, MD 20850. E-mail:
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25
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External quality assurance of malaria nucleic acid testing for clinical trials and eradication surveillance. PLoS One 2014; 9:e97398. [PMID: 24838112 PMCID: PMC4023973 DOI: 10.1371/journal.pone.0097398] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 04/18/2014] [Indexed: 11/19/2022] Open
Abstract
Nucleic acid testing (NAT) for malaria parasites is an increasingly recommended diagnostic endpoint in clinical trials of vaccine and drug candidates and is also important in surveillance of malaria control and elimination efforts. A variety of reported NAT assays have been described, yet no formal external quality assurance (EQA) program provides validation for the assays in use. Here, we report results of an EQA exercise for malaria NAT assays. Among five centers conducting controlled human malaria infection trials, all centers achieved 100% specificity and demonstrated limits of detection consistent with each laboratory's pre-stated expectations. Quantitative bias of reported results compared to expected results was generally <0.5 log10 parasites/mL except for one laboratory where the EQA effort identified likely reasons for a general quantitative shift. The within-laboratory variation for all assays was low at <10% coefficient of variation across a range of parasite densities. Based on this study, we propose to create a Molecular Malaria Quality Assessment program that fulfills the need for EQA of malaria NAT assays worldwide.
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