Division of Clinical Immunology, Department of Medicine, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.
IRD, MERIT, Université Paris Cité, 75006, Paris, France.
Malar J. 2024 May 19;23(1):154. doi: 10.1186/s12936-024-04970-7.
Plasmodium falciparum malaria is a public health issue mostly seen in tropical countries. Until now, there is no effective malaria vaccine against antigens specific to the blood-stage of P. falciparum infection. Because the pathogenesis of malarial disease results from blood-stage infection, it is essential to identify the most promising blood-stage vaccine candidate antigens under natural exposure to malaria infection.
A cohort of 400 pregnant women and their infants was implemented in South Benin. An active and passive protocol of malaria surveillance was established during pregnancy and infancy to precisely ascertain malaria infections during the follow-up. Twenty-eight antibody (Ab) responses specific to seven malaria candidate vaccine antigens were repeatedly quantified during pregnancy (3 time points) and infancy (6 time points) in order to study the Ab kinetics and their protective role. Abs were quantified by ELISA and logistic, linear and cox-proportional hazard model were performed to analyse the associations between Ab responses and protection against malaria in mothers and infants, taking into account socio-economic factors and for infants an environmental risk of exposure.
The levels of IgM against MSP1, MSP2 and MSP3 showed an early protective response against the onset of symptomatic malaria infections starting from the 18th month of life, whereas no association was found for IgG responses during infancy. In women, some IgG responses tend to be associated with a protection against malaria risk along pregnancy and at delivery, among them IgG3 against GLURP-R0 and IgG2 against MSP1.
The main finding suggests that IgM should be considered in vaccine designs during infanthood. Investigation of the functional role played by IgM in malaria protection needs further attention.
恶性疟原虫疟疾是一种主要发生在热带国家的公共卫生问题。到目前为止，还没有针对恶性疟原虫感染血阶段的有效疟疾疫苗。由于疟疾疾病的发病机制源于血阶段感染，因此识别在自然暴露于疟疾感染下最有前途的血阶段疫苗候选抗原至关重要。
在贝宁南部实施了一项由 400 名孕妇及其婴儿组成的队列研究。在妊娠和婴儿期建立了主动和被动的疟疾监测方案，以在随访期间准确确定疟疾感染情况。在妊娠期间（3 个时间点）和婴儿期（6 个时间点）反复定量检测 7 种疟疾候选疫苗抗原的 28 种抗体（Ab）反应，以研究 Ab 动力学及其对母亲和婴儿的保护作用。通过 ELISA 定量 Abs，并通过逻辑回归、线性和 Cox 比例风险模型分析 Ab 反应与母亲和婴儿免受疟疾感染的关联，同时考虑社会经济因素，对于婴儿，还考虑了环境暴露风险。
抗 MSP1、MSP2 和 MSP3 的 IgM 水平显示出对 18 个月龄后出现的有症状疟疾感染的早期保护反应，而在婴儿期 IgG 反应则没有关联。在女性中，一些 IgG 反应似乎与妊娠期间和分娩时的疟疾风险保护有关，其中包括针对 GLURP-R0 的 IgG3 和针对 MSP1 的 IgG2。
主要发现表明，在婴儿期疫苗设计中应考虑 IgM。进一步关注 IgM 在疟疾保护中的功能作用的研究是必要的。
