Polio Vaccination: Past, Present and Future

Abstract

Live attenuated oral polio vaccine (OPV) and inactivated polio vaccine (IPV) are the tools being used to achieve eradication of wild polio virus. Because OPV can rarely cause paralysis and generate revertant polio strains, IPV will have to replace OPV after eradication of wild polio virus is certified to sustain eradication of all polioviruses. However, uncertainties remain related to IPV's ability to induce intestinal immunity in populations where fecal-oral transmission is predominant. Although substantial effectiveness and safety data exist on the use and delivery of OPV and IPV, several new research initiatives are currently underway to fill specific knowledge gaps to inform future vaccination policies that would assure polio is eradicated and eradication is maintained.

The polio endgame: rationale behind the change in immunisation

“…Two drug candidates for treatment of B-cell immune-deficient long-term excreters are in late-stage clinical trials with promising results in reduction of shedding among participants 31. Finally, numerous tools and technologies capable of making IPV production safer and development of stable OPV with less risk of reversion to infective virus are also being explored 10 32…”

The past, present, and future of immunization in the Americas

“…The clinical evidence-base generated from these studies has contributed to the global policy formulation for the polio endgame. (10)(11)(12)(13)(14)(15) To commemorate the 40 th anniversary of EPI in the Americas, this supplement of the Pan American Journal of Public Health summarizes the past, provides a critical analysis of the present, and offers new perspectives on future challenges and opportunities. The call for specific articles was well received: original articles, reviews, opinion pieces, and special reports were submitted reflecting regional, subregional, and country-specific perspectives.…”

Inactivated polio vaccines from three different manufacturers have equivalent safety and immunogenicity when given as 1 or 2 additional doses after bivalent OPV: Results from a randomized controlled trial in Latin America

“…bOPV maintains protection against type 1 and 3 polioviruses, but leaves young children vulnerable to infection by type 2 vaccine-derived polioviruses [1], [2]. To strengthen population immunity and ensure all children are protected against type 2 polioviruses in countries that are polio-endemic or at high risk of importation of the virus, the WHO Strategic Advisory Group of Experts (SAGE) recommends at least one dose of IPV, given with the third dose of bOPV at 14 weeks of age or older to minimize interference from maternally-derived antibodies [3].…”