Although antibodies are considered critical for malaria protection, little is known about the mechanisms/factors that maintain humoral immunity, especially regarding the induction and maintenance of memory B cells over time. In Brazilian endemic areas, this is the first time that the profile of antibody responses and the occurrence of antigen‐specific memory B cells (MBC) against P vivax were investigated during acute malaria and up to six months after parasite clearance. For this, we selected two peptides, PvAMA‐1_{(S290‐K307)} and PvMSP‐9_{(E795‐A808)}, which represent the apical membrane antigen‐1 and merozoite surface protein‐9 of P vivax, respectively. Both peptides were previously described as containing linear B‐cell epitopes. Our findings were as follows: 1—both peptides were recognized by IgG antibodies at a high frequency (between 24% and 81%) in all study groups; 2—in the absence of infection, the IgG levels remained stable throughout 6 months of follow‐up; and 3—PvAMA‐1_{(S290‐K307)} and PvMSP‐9_{(E795‐A808)}‐specific MBCs were detected in all individual groups in the absence of reinfection throughout the follow‐up period, suggesting long‐lived MBC. However, no positive association was observed between malaria‐specific antibody levels and frequency of MBCs over time. Taken together, these results suggest that peptides can be, in the future, an alternative strategy to polypeptidic vaccine formulation.

中文翻译：

---

在间日疟疾的急性期和恢复期，PvAMA-1和PvMSP-9的主要B细胞表位被天然获得的抗体和表位特异性记忆细胞所靶向。

尽管抗体被认为对疟疾的保护至关重要，但对维持体液免疫的机制/因素知之甚少，尤其是随着时间的推移记忆B细胞的诱导和维持。在巴西流行地区，这是首次在急性疟疾期间和寄生虫清除后六个月内调查抗体应答和针对间日疟原虫的抗原特异性记忆B细胞（MBC）的发生情况。为此，我们选择了两种肽PvAMA-1 _{（S290-K307）}和PvMSP-9 _{（E795-A808）}，它们代表间日疟原虫的顶膜抗原-1和裂殖子表面蛋白-9。， 分别。两种肽以前都被描述为含有线性B细胞表位。我们的发现如下：1 —在所有研究组中，两种肽均被IgG抗体以高频率（24％至81％）识别。2-在没有感染的情况下，在随访的6个月中IgG水平保持稳定；和3-在整个随访期间均未进行再感染的情况下，在所有个体中均检测到了PvAMA-1 _{（S290-K307）}和PvMSP-9 _{（E795-A808）}特异性MBC，这表明MBC寿命长。但是，随着时间的推移，在疟疾特异性抗体水平和MBC频率之间未发现正相关。综上所述，这些结果表明，肽可以在将来成为多肽疫苗制剂的替代策略。