Seroprotection against tetanus in HIV-exposed and HIV-unexposed infants in Malawi in 2019–2020

In Malawi, tetanus toxoid vaccination (TTV) is recommended in pregnancy, but few studies have assessed the prevalence of infant seroprotection against tetanus. Anti-TT levels from 84 6-week-old infants, born in 2019–2020 to mothers living with HIV (HEU: HIV-exposed-uninfected) infants and to HIV-negative women (HUU: HIV-unexposed-uninfected) infants were determined by ELISA assay. Although 94% of the infants (HEU=94.8%, HUU=92.3%) showed protective levels (>0.1 IU/mL), the mean titers observed (0.51 IU/mL) suggest an incomplete compliance with TT vaccination. The only factor positively correlated to anti-TT IgG levels was the duration of maternal antiretroviral therapy in HEU.