A team of researchers from the Maternal, Child and Reproductive Health Initiative and the Malaria Physiopathology group at ISGlobal together with colleagues from the Manhia Health Research Centre (CISM), Mozambique, shows that malaria and HIV infection during pregnancy is associated with a decrease in the amount of malaria-specific antibodies that are transferred from the mother to the child via the placenta. Curiously, this reduction does not seem to increase malaria susceptibility of the infant. However, the results of this study, published in the Journal of Infectious Diseases, indicate that these infections can limit the efficacy of child immunization strategies based on the vaccination of pregnant women.

During pregnancy, antibodies are transferred from mother to child through the placenta, resulting in an efficient but short-term protection of the newborn. However, it is not clear whether the placental transfer of antimalarial antibodies decreases the infant's susceptibility to malaria during the first months of life. In Mozambique, a malaria-endemic region, approximately one out of four pregnant women is infected with HIV and it has been reported that HIV reduced placental transfer of antibodies specific for common virus and bacteria. Thus, this study had two goals: first, determine whether malaria and HIV infection affect the placental transfer of malaria-specific antibodies, and second, evaluate the potential relationship between antibody transfer and pregnancy outcomes or malaria risk among newborns. 

The results show that HIV infection reduces placental transfer of malaria-specific antibodies, as previously reported for several virus and bacteria. The researchers show, for the first time, that malaria by itself is also associated with lower levels of IgG antibodies directed against several malaria parasite proteins, in the umbilical cord blood. Such decrease in antibody levels does not seem to correlate with a higher risk of malaria infection during the first year of life, and the authors conclude that other physiological factors may contribute to infant protection. The researchers point out that "the consequences of the reduced materno-fetal antibody transfer associated with HIV and malaria deserves further investigation for the design of effective vaccines in pregnancy, particularly in endemic regions". 

Around 25 million pregnant women in Sub-Saharian Africa are at risk of contracting malaria, while HIV prevalence among pregnant women can reach 25%. 

cia de VIH durante el embarazo puede llegar a ser mayor del 25%.