Independent evaluation calls for more research to maximize impact of eradication strategies

In 2009, an Independent evaluation of major barriers to interrupting poliovirus transmission was conducted, in response to a request in January 2009 from the Executive Board of the World Health Assembly, prompted by delays in attaining global eradication.

The Independent evaluation comprised five sub-teams with a total of 28 experts in relevant disciplines, including public health, immunization, vaccinology, social mobilization and security. These sub-teams worked in Afghanistan, Angola, India, Nigeria, Pakistan, Sudan and the WHO Regional offices for Africa and the Eastern Mediterranean, in consultation with partners and stakeholders in each country.

While the Independent evaluation provided a range of new technical recommendations for each polio-affected area, such as the rapid application of new tools including bivalent OPV, the group’s recommendations also have significant implications for the Global Polio Eradication Initiative’s research programme.

In particular, the group reinforced the importance of an aggressive and multi-pronged research agenda to overcome the unique challenge posed by incomplete gut mucosal immunity to polioviruses and uniquely efficient virus transmission in the setting of northern India. To this effect, conferred gut immunity by oral polio vaccine (OPV) versus inactivated polio vaccine (IPV) should be evaluated, as well as the effect of poor nutrition and chronic diarrhoeal incidence on immunity levels.

At the same time, the effects of adding zinc supplementation (which has been shown to be associated with a reduction in diarrhoeal incidence) during polio supplementary immunization activities, and the benefits of implementing basic sanitation measures (e.g. protecting hand-pumps from faecal contamination), should be examined. For other areas, in particular in outbreak settings, the benefits of the new Short Interval Additional Dose (SIAD) approach should be quantifiably evidenced