Some
vaccines show poor efficacy in tropical countries. Within a birth cohort in Uganda, we investigated factors that might influence responses to BCG and
tetanus immunisation. Whole blood assay responses to crude culture filtrate
proteins of Mycobacterium tuberculosis (cCFP)) and
tetanus toxoid (TT) were examined among 1506 and 1433 one-year-olds, respectively. Maternal
Mansonella perstans infection was associated with higher
interleukin (IL)-10 responses to both immunogens but no reduction in
gamma interferon (IFN-γ), IL-5 and
IL-13 responses; other maternal helminth
infections showed little effect.
Tetanus immunisation during pregnancy was associated with higher infant responses to TT; maternal BCG
scar (from past immunisation) with lower infant IL-5 and
IL-13 responses to cCFP. IFN-γ, IL-5 and
IL-13 to TT were reduced in HIV-exposed-uninfected infants; infant
malaria and HIV were associated with lower IFN-γ, IL-5 and
IL-13 responses to both immunogens. We conclude that maternal helminth
infections are unlikely to explain poor
vaccine efficacy in the tropics. Effects of maternal immunisation on infant responses to
vaccines should be explored. Prevention of infant
malaria and HIV could contribute to effectiveness of immunisation programmes.