Fractional-dose inactivated poliovirus vaccination campaign, Telangana state, India, June 2016

Wild poliovirus type 2 was declared eradicated in September 2015. As part of a

globally-synchronized effort to withdraw Sabin poliovirus type 2 vaccine, India switched from use of trivalent oral poliovirus vaccine (tOPV) to bivalent type 1 and 3 OPV (bOPV) in April 2016. Concurrently, inactivated poliovirus vaccine (IPV) was introduced to the routine immunization programme to maintain an immunity base that would mitigate the number of paralytic cases in the event of epidemic transmission of poliovirus type 2. After cessation of type 2 Sabin vaccine use, any reported vaccine-derived poliovirus type 2 (VDPV2) would be treated as a public health emergency and may need outbreak response with monovalent type 2 oral vaccine and/or IPV. In response to an isolation of VDPV2 from a sewage sample taken in Telangana state, India conducted a mass campaign using an intradermal fractional dose (0.1 ml) of IPV (fIPV) in June 2016. Over a period of 6 days, the campaign vaccinated 311 064 children aged from 6 weeks to 3 years. Reaching an estimated coverage of 94%, this indicated that, with appropriate preparation, an emergency response of fIPV could be implemented promptly and successfully without adverse consequences. The lessons learned can be applied to the successful implementation of future outbreak responses using fIPV.