Differences in the immune response to hepatitis B and Haemophilus influenzae type b vaccines in Guatemalan infants by ethnic group and nutritional status.

Ladino and native Indian Guatemalan infants developed high rates (96-100%) of protective antibodies after receiving conjugate Haemophilus influenzae type b and hepatitis B vaccines at 2, 4 and 6 months of age. Native Indian infants developed significantly (p<0.01) higher geometric mean anti-PRP (polyribose-ribitol-phosphate) and anti-HBs (anti-hepatitis b surface) antibody concentrations than Ladino infants. Malnourished infants generally responded as well as healthy infants. Unvaccinated native Indian infants had higher rates of developing anti-PRP antibodies than Ladino infants by seven months of age.