biostudies-literatureTashi TNational Health and Medical Research Council of AustraliaConselho Nacional de Desenvolvimento Científico e TecnológicoCNPq senior research fellowshipHoward Hughes Medical Institute-Wellcome Trust International Research ScholarNational Institutes of Health (NIH), National Center for Advancing Translational SciencesMichael J. Fox FoundationCAPES doctoral fellowshipNational Health and Medical Research CouncilFundação de Amparo à Pesquisa de Minas GeraisNIHWellcome Truste0010773https://www.ebi.ac.uk/biostudies/studies/S-EPMC9728838biostudies-literatureUnknown16(11)<h4>Background</h4>To make progress towards malaria elimination, a highly effective vaccine targeting Plasmodium vivax is urgently needed. Evaluating the kinetics of natural antibody responses to vaccine candidate antigens after acute vivax malaria can inform the design of serological markers of exposure and vaccines.<h4>Methodology/principal findings</h4>The responses of IgG antibodies to 9 P. vivax vaccine candidate antigens were evaluated in longitudinal serum samples from Brazilian individuals collected at the time of acute vivax malaria and 30, 60, and 180 days afterwards. Antigen-specific IgG correlations, seroprevalence, and half-lives were determined for each antigen using the longitudinal data. Antibody reactivities against Pv41 and PVX_081550 strongly correlated with each other at each of the four time points. The analysis identified robust responses in terms of magnitude and seroprevalence against Pv41 and PvGAMA at 30 and 60 days. Among the 8 P. vivax antigens demonstrating >50% seropositivity across all individuals, antibodies specific to PVX_081550 had the longest half-life (100 days; 95% CI, 83-130 days), followed by PvRBP2b (91 days; 95% CI, 76-110 days) and Pv12 (82 days; 95% CI, 64-110 days).<h4>Conclusion/significance</h4>This study provides an in-depth assessment of the kinetics of antibody responses to key vaccine candidate antigens in Brazilians with acute vivax malaria. Follow-up studies are needed to determine whether the longer-lived antibody responses induced by natural infection are effective in controlling blood-stage infection and mediating clinical protection.PLoS neglected tropical diseasesLongitudinal IgG antibody responses to Plasmodium vivax blood-stage antigens during and after acute vivax malaria in individuals living in the Brazilian Amazon.PMC9728838GNT1173210208693/Z/17/ZGNT1134989, GNT1132975 and GNT1043345APQ-00769-12R01GM111639, R01GM115844GNT1160042, GNT1154937470315/2012-1R01 AI137154UL1TR002529K08AI125682Rayner JCFerreira MUHoang QQWu CMenant STashi TLima-Junior JCKundu PMueller ITran TMUpadhye ALongley RJTham WHSoares RRScopel KKfalseLongitudinal IgG antibody responses to Plasmodium vivax blood-stage antigens during and after acute vivax malaria in individuals living in the Brazilian Amazon.<h4>Background</h4>To make progress towards malaria elimination, a highly effective vaccine targeting Plasmodium vivax is urgently needed. Evaluating the kinetics of natural antibody responses to vaccine candidate antigens after acute vivax malaria can inform the design of serological markers of exposure and vaccines.<h4>Methodology/principal findings</h4>The responses of IgG antibodies to 9 P. vivax vaccine candidate antigens were evaluated in longitudinal serum samples from Brazilian individuals collected at the time of acute vivax malaria and 30, 60, and 180 days afterwards. Antigen-specific IgG correlations, seroprevalence, and half-lives were determined for each antigen using the longitudinal data. Antibody reactivities against Pv41 and PVX_081550 strongly correlated with each other at each of the four time points. The analysis identified robust responses in terms of magnitude and seroprevalence against Pv41 and PvGAMA at 30 and 60 days. Among the 8 P. vivax antigens demonstrating >50% seropositivity across all individuals, antibodies specific to PVX_081550 had the longest half-life (100 days; 95% CI, 83-130 days), followed by PvRBP2b (91 days; 95% CI, 76-110 days) and Pv12 (82 days; 95% CI, 64-110 days).<h4>Conclusion/significance</h4>This study provides an in-depth assessment of the kinetics of antibody responses to key vaccine candidate antigens in Brazilians with acute vivax malaria. Follow-up studies are needed to determine whether the longer-lived antibody responses induced by natural infection are effective in controlling blood-stage infection and mediating clinical protection.2022-01-01T00:00:00Z2022 Nov2025-04-05T12:53:22.254Z2025-04-05T12:53:22.254ZS-EPMC97288383641745410.1371/journal.pntd.0010773