Specific antibody responses to Qβ‐displayed Plasmodium falciparum‐derived UB05 and MSP3 proteins in mother–neonate couples

Malaria blood-stage parasite is a critical pathogenic stage responsible for serious adverse outcomes in pregnant women and their neonates. Immunoglobulin G (IgG) antibody responses specific to various asexual blood-stage antigens were well reported in non-pregnant individuals. However, little is still known during placental malaria. To assess the antibody responses specific to Plasmodium falciparum-derived MSP3 and UB05 malaria vaccine candidates in mother-neonate couples, mother's peripheral blood and neonate's cord blood samples were collected at delivery. After malaria diagnostic, plasma levels of IgG and IgG subclass responses specific to UB05, MSP3 and UB05-MSP3 were determined using ELISA. As outcomes, both mothers and neonates had significantly higher IgG responses to UB05 and UB05-MSP3 compared to anti-MSP3 IgG (p < 0.05), irrespective of malaria status. Significant negative correlations were observed between IgG levels specific to the three antigens and parasitaemia (p < 0.01). Anti-UB05 and anti-UB05-MSP3 IgG levels in neonates showed a significant positive correlation with the corresponding mothers' antibodies (r