An unexpected benefit of inactivated poliovirus vaccine

This study shows that a dose of IPV is more effective than OPV at boosting intestinal immunity in children who have previously been immunized with OPV. Both IPV and OPV should be used together in the polio eradication program. WHO therefore recommends the following vaccine regimens: In all countries using OPV only, at least 1 dose of type 2 IPV should be added to the schedule. In polio-endemic countries and in countries with a high risk for wild poliovirus importation and spread: one OPV birth dose, followed by 3 OPV and at least 1 IPV doses. In countries with high immunization coverage (90-95%) and low wild poliovirus importation risk: an IPV-OPV sequential schedule when VAPP is a concern, comprising 1-2 doses of IPV followed by 2 or mores doses of OPV. In countries with both sustained high immunization coverage and low risk of wild poliovirus importation and transmission: an IPV only schedule. Type 2 OPV will be gradually removed from the global immunization schedules. There have been no reported cases of type 3 poliovirus since November 2012. If this wild type virus is declared eradicated later this year, presumably WHO will recommend withdrawal of type 3 OPV and replacement with type 3 IPV. All 342 confirmed cases of poliomyelitis in 2014 were caused by type 1 poliovirus in 9 countries, mainly Pakistan and Afghanistan. Given the social and political barriers to immunization, it will likely take many years to eradicate this serotype.
Source: virology blog - Category: Virology Authors: Tags: Basic virology Information Albert Sabin eradication humoral immunity inactivated poliovirus vaccine IPV jonas salk mucosal immunity OPV oral poliovirus vaccine poliomyelitis vaccine associated paralytic polio vaccine-derived poli Source Type: blogs