Emerging challenges to realizing global polio eradication and their solutions.

BACKGROUND

The Global Polio Eradication Initiative (GPEI) promised to eradicate polio by 2000, yet the disease remains endemic in 2 countries. The current threat of resurgence in countries with low vaccine coverage and circulating vaccinederived poliovirus (cVDPV) outbreaks due to oral polio vaccine warrants a strategy review.

AIMS: To review the performance of the GPEI from a context based in Pakistan, identifying threats to success and suggesting strategy modifications to help achieve eradication.

METHODS

This was a desk review of the effectiveness of GPEI that was launched in 1988 to eradicate polio by 2000. Subsequent failure to eradicate led to multiple iterations in strategy and planning documents. These documents were reviewed alongside relevant literature to explore the reasons for failure and emergence of cVDPV.

RESULTS

GPEI has been effective in reducing the global polio disease burden by > 99%, but it remains endemic in Pakistan and Afghanistan. cVDPV has caused multiple outbreaks since 2000, and caused 7 times more cases than wild poliovirus (WPV) globally in 2020. The Polio Eradication and Endgame Strategic Plan 2013-2018 aimed to eradicate WPV and cVDPV simultaneously. In 2019, Pakistan saw an upsurge in WPV amid an outbreak of cVDPV infection that continued throughout 2020. Wild polio eradication was not realized and the country was unable to transition to inactivated polio vaccine as predicted in the strategic plan.

CONCLUSION

Over 20 countries now report cVDPV outbreaks and many others are at risk. A country-specific modified strategy is required to eradicate WPV and cVDPV simultaneously, more so in endemic countries.