Oral polio vaccination in infants: beneficial effect of additional dose at birth.

This study was done to assess the response of newborns to trivalent oral polio vaccine and to study any efficacy of OPV if given to infants on third day of life. The study was conducted in two groups, A (87) and B (55) of infants in Delhi, India. In group A, the children received one birth dose or 'O' dose of TOPV, followed by 3 conventional doses started at 6 weeks, and in group B the children received only 3 doses of OPV. Pre and one month post immunization serum samples were tested for the presence of neutralising antibodies. In addition, in group A serum samples were collected at 6 weeks before the administration of 1st dose to see the sero response following 'O' dose of TOPV. It was found that administration of OPV on 3rd day of life leads to sero conversion in 15.3% of infants to all three polio virus types by the age of 6 weeks, and highest sero response was seen for polio virus type 1. Sero-conversion in group A was significantly more than sero-conversion in group B after the administration of last dose. Thus the study has established that immunization of newborns with TOPV is a safe and effective means for improving protection against the disease.