Plasmodium vivax remains an important cause of malaria in South America and Asia, and analyses of the antibody immune response are being used to identify biomarker of parasite exposure. The IgG antibody naturally acquired predominantly occurs against targets on blood-stage parasites, including C-terminal of the merozoite surface protein 1 (MSP1-19). Epidemiological and immunological evidence has been showed that antibodies to malaria parasite antigens are lost in the absence of ongoing exposure. We describe the IgG antibody response in individuals living in an unstable malaria transmission area in Pará state, Amazon region, Brazil, where an epidemic of P. vivax malaria was recorded and monitored over time. As indicated by epidemiological data, the number of P. vivax-caused malaria cases decreased by approximately 90% after three years and the prevalence of IgG positive to PvMSP1-19 decreased significantly over time, in 2010 (93.4 %), 2012 (78.3%), and 2013 (85.1%). Acquisition and decay of the IgG antibody against P. vivax MSP1-19 showed variability among individuals living in areas with recent circulating parasites, where the malaria epidemic was being monitored until transmission had been completely controlled. We also found that previous malaria episodes were associated to IgG positivity rates. Our results showed epidemiological, spatial, temporal and individual variability. The understanding on dynamics of antibodies may have implications for the design of serosurveillance tools for monitoring parasite circulation, especially in a context with spatial and temporal changes in P. vivax malaria transmission.

间日疟原虫仍然是南美和亚洲疟疾的重要原因，抗体免疫反应的分析被用于鉴定寄生虫暴露的生物标志物。天然获得的IgG抗体主要针对血阶段寄生虫的靶标，包括裂殖子表面蛋白1（MSP1-19）的C端。流行病学和免疫学证据表明，在没有持续暴露的情况下，抗疟疾寄生虫抗原的抗体会丢失。我们描述了生活在巴西亚马逊州帕拉州一个不稳定疟疾传播地区的个体中的IgG抗体应答，该病在一段时间内记录并监测了间日疟原虫的流行。如流行病学数据所示，间日疟原虫导致的疟疾病例在三年后下降了约90％，PvMSP1-19阳性IgG的流行率随时间显着下降，2010年（93.4％），2012年（78.3％）和2013年（85.1％）。抗间日疟原虫IgG抗体的获取和降解MSP1-19显示了生活在最近流行的寄生虫地区的个体之间的变异性，在那里对疟疾流行进行监测，直到完全控制了传播。我们还发现以前的疟疾发作与IgG阳性率有关。我们的结果表明，流行病学，空间，时间和个体差异。对抗体动力学的理解可能对监测寄生虫循环的血清监测工具的设计有影响，特别是在间日疟原虫疟疾传播时空变化的情况下。