Immune response of neonates to oral poliomyelitis vaccine.

Newborn children 1 to 6 weeks of age were given oral polio vaccines to see whether the age limit of 6-8 weeks for the current Indian immunization program could be reduced. 180 neonates received oral polio vaccines followed by 2nd and 3rd doses at 4 week intervals. Breast feeding was delayed 30 minutes after vaccination. In 139 infants tested after the 3rd dose the titers against type 1 2 or 3 polio virus expressed as percentage of seroconversion did not differ from those seen in groups of children aged 6-20 or 6-51 weeks of age. Babies less than 1 week old were not tested because the literature suggests that their antibody response is inhibited. These results show that maternal antibodies do not prevent local infection by poliovirus in the gut of infants as young as 1 week old.