Deficit of IgG2 in HIV-positive pregnant women is responsible of inadequate IgG2 levels in their HIV-uninfected children in Malawi.

Transplacental passage was reduced for all IgG subclasses and inversely correlated to high levels of maternal IgGs and to the degree of immunoactivation. The profound depression of IgG2 in mothers suggests that IgG2 neonatal levels mostly reflect the maternal deficit rather than a selective impairment of IgG2 transfer.