Trial reportMalaria journal2010
Lack of allele-specific efficacy of a bivalent AMA1 malaria vaccine.
Trial report in Malaria journal, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 45 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
45 citing papers in PubMed, 68 citations in OpenAlex.
- Molecular basis of allele-specific efficacy of a blood-stage malaria vaccine: vaccine development implications.The Journal of infectious diseases · 2013Trial
- Trial
- A field trial to assess a blood-stage malaria vaccine.The New England journal of medicine · 2011Trial
- Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine.Malaria journal · 2011Trial
- Distribution of Plasmodium falciparum apical membrane antigen-1 cluster one loop haplotypes and their association with malaria symptoms in Bandiagara, Mali.BMC infectious diseases · 2026Article
- A broadly cross-reactive i-body to AMA1 potently inhibits blood and liver stages of Plasmodium parasites.Nature communications · 2024Article
- The Need for Novel Asexual Blood-Stage Malaria Vaccine Candidates forBiomolecules · 2024Review
- Mining gene expression data for rational identification of novel drug targets and vaccine candidates against the cattle tick, Rhipicephalus microplus.Experimental & applied acarology · 2023Article
- Structure guided mimicry of an essential P. falciparum receptor-ligand complex enhances cross neutralizing antibodies.Nature communications · 2023Article
- Structure guided mimicry of an essential P. falciparum receptor-ligand complex enhances cross neutralizing antibodies.Research square · 2023Article
- An In Silico Analysis of Malaria Pre-Erythrocytic-Stage Antigens Interpreting Worldwide Genetic Data to Suggest Vaccine Candidate Variants and Epitopes.Microorganisms · 2022Article
- RTS,S today and tomorrow's science.Cell host & microbe · 2022Article
- Sequence Analysis of Pvama-1 amongEthiopian journal of health sciences · 2020Article
- Host-Malaria Parasite Interactions and Impacts on Mutual Evolution.Frontiers in cellular and infection microbiology · 2020Review
- Targets of complement-fixing antibodies in protective immunity against malaria in children.Nature communications · 2019Article
- Comprehensive Review of HumanFrontiers in immunology · 2019Review
- Review
- Extent and Dynamics of Polymorphism in the Malaria Vaccine CandidateThe American journal of tropical medicine and hygiene · 2018Article
- Unraveling Haplotype Diversity of the Apical Membrane Antigen-1 Gene inThe Korean journal of parasitology · 2018Article
- Malaria Epidemiology at the Clone Level.Trends in parasitology · 2017Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
13 authors at 7 institutions in 2 countries.
Funding
Abstract
backgroundExtensive genetic diversity in vaccine antigens may contribute to the lack of efficacy of blood stage malaria vaccines. Apical membrane antigen-1 (AMA1) is a leading blood stage malaria vaccine candidate with extreme diversity, potentially limiting its efficacy against infection and disease caused by Plasmodium falciparum parasites with diverse forms of AMA1.
methodsThree hundred Malian children participated in a Phase 2 clinical trial of a bivalent malaria vaccine that found no protective efficacy. The vaccine consists of recombinant AMA1 based on the 3D7 and FVO strains of P. falciparum adjuvanted with aluminum hydroxide (AMA1-C1). The gene encoding AMA1 was sequenced from P. falciparum infections experienced before and after immunization with the study vaccine or a control vaccine. Sequences of ama1 from infections in the malaria vaccine and control groups were compared with regard to similarity to the vaccine antigens using several measures of genetic diversity. Time to infection with parasites carrying AMA1 haplotypes similar to the vaccine strains with respect to immunologically important polymorphisms and the risk of infection with vaccine strain haplotypes were compared.
resultsBased on 62 polymorphic AMA1 residues, 186 unique ama1 haplotypes were identified among 315 ama1 sequences that were included in the analysis. Eight infections had ama1 sequences identical to 3D7 while none were identical to FVO. Several measures of genetic diversity showed that ama1 sequences in the malaria vaccine and control groups were comparable both at baseline and during follow up period. Pre- and post-immunization ama1 sequences in both groups all had a similar degree of genetic distance from FVO and 3D7 ama1. No differences were found in the time of first clinical episode or risk of infection with an AMA1 haplotype similar to 3D7 or FVO with respect to a limited set of immunologically important polymorphisms found in the cluster 1 loop of domain I of AMA1.
conclusionThis Phase 2 trial of a bivalent AMA1 malaria vaccine found no evidence of vaccine selection or strain-specific efficacy, suggesting that the extreme genetic diversity of AMA1 did not account for failure of the vaccine to provide protection.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.