ABSTRACT
Three hundred Indian infants between 6 and 51 weeks of age were divided into six groups and given three doses of trivalent oral polio vaccine (OPV) of known adequate potency. One group was on unrestricted breast-feeding with mandatory breast-feed during the interval between 30 minutes before and 15 minutes after each dose of OPV. In four groups of infants breast-feeding was withheld for three, four, five, and six hours both before and after each dose of OPV. The sixth group was bottle-fed. Samples of blood were collected from all infants before vaccination and from 227 infants further samples were collected four weeks after the first and/or third doses of OPV. Antibody responses to poliovirus types 1, 2, and 3 were determined following one dose and three doses of OPV, and the rates of response were found to be approximately equal in all groups of breast-fed infants irrespective of their feeding schedules, as well as in bottle-fed infants. Thus breast-feeding is shown to have no inhibitory effect on antibody response of infants beyond the newborn period to OPV.
