According to the Consensus Recommendation on Immunization 2012 [1] the Committee recommends birth dose of OPV, three primary doses of IPV at 6, 10 and 14 weeks, followed by two doses of OPV at 6 and 9 months. It further states that since IPV administered to infants in EPI schedule (i.e., 6 weeks, 10 weeks and 14 weeks) results in suboptimal seroconversion, hence a supplementary dose of IPV is recommended at 15-18 months. Will administration of two doses of OPV not enhance the levels of antibodies generated by three doses of IPV so that supplementary dose of IPV at 15-18 months be eliminated?

The Committee further states that there is considerable evidence to show that sequential schedules that provide IPV first followed by OPV can prevent VAPP while maintaining the critical benefits conferred by OPV (i.e., high levels of gut immunity). In case subsequent administration of OPV is to provide ‘critical benefit of gut immunity’, it would be interesting to know the reasons why children from the countries which have switched over to IPV only are being deprived of ‘critical benefit of gut immunity’.