Vaccine-associated paralytic poliomyelitis in the Russian Federation in 1998–2014

Objectives: Different polio vaccination schemes have been used in Russia: oral polio vaccine (OPV) was used in 1998–2007 and inactivated polio vaccine (IPV) followed by OPV in 2008–2014. This article presents the characteristics of vaccine-associated paralytic poliomyelitis (VAPP) cases in Russia during this period. Methods: VAPP cases were identified through the acute flaccid paralysis surveillance system, classified by the National Expert Classification Committee. Criteria for a ‘recipient VAPP’ (rVAPP) case were poliomyelitis symptoms 6–30 days after OPV administration, isolation of the vaccine virus, and residual paralysis 60 days after disease onset. Unvaccinated cases with a similar picture 6–60 days after contact with an OPV recipient were classified as ‘contact VAPP’ (cVAPP) cases. Results: During 1998–2014, 127 VAPP cases were registered: 82 rVAPP and 45 cVAPP. During the period in which only OPV was used, rVAPP cases prevailed (73.8%); cases of rVAPP were reduced during the sequential scheme period (15%). Poliovirus type 3 (39.5%) and type 2 (23.7%) were isolated more often. Vaccine-derived poliovirus types 1, 2, and 3 were isolated from three cases of cVAPP. The incidence of VAPP cases was higher during the period of OPV use (1 case/1.59 million OPV doses) than during the sequential scheme period (1 case/4.18 million doses). Conclusion: The risk of VAPP exists if OPV remains in the vaccination schedule. Keywords: Poliomyelitis, VAPP, Poliovirus vaccine, IPV, OPV