Antibody response of infants in tropics to five doses of oral polio vaccine.

Abstract

Sixty-two infants 1-12 months of age were administered five doses of trivalent oral polio vaccine (TOPV) at intervals of 4 weeks. The seroconversion achieved were 88.7, 93.5 and 96.5 per cent for type I, II, and III polioviruses. These seroconversion rates are significantly better when compared to seroconversion achieved after two and three doses of trivalent oral polio vaccine. Factors which were considered in previous studies to be responsible for low seroconversion rates viz. interference by enteroviruses, breast feeding, malnutrition, and age were found to be insignificant when five doses of oral polio vaccine were given. It is possible that these effects were overcome by increasing the number of doses of trivalent oral polio vaccine.