Thirty two years ago, the world health leaders launched a brave undertaking – the eradication of the three strains of wild polio virus that had sustained a life threatening and disabling disease globally. Since then, the Global Polio Eradication Initiative (GPEI) has yielded 99% decrease in cases of poliomyelitis, ended the transmission of two of the three wild type viruses that cause polio, and completed elimination of the disease in all countries except Afghanistan and Pakistan, which in 2019 reported less than 200 cases. Certification of complete eradication is so tantalizingly near!
Certification of complete polio eradication is so tantalizingly near!
Along the way to these impressive gains, the global programme has achieved not only the capacity to vaccinate hundreds of millions of children through routine immunization systems and targeted campaigns, but also a transformative data collection system that tracks, down to the genetics, every poliovirus identified in people, as well as routine testing of samples recovered from sewage to make sure that there is no virus circulating in the community, in order to identify infections before they lead to a polio outbreak. GPEI has engaged an ever broadening community to make this feasible, including national leaders, churches of all denominations, community leaders, companies, foundations, and global health structures, as an overarching global health priority.
But the history has not been straightforward, the delays to achieve the final target of polio eradication –originally set for the year 2000, new challenges have been identified, most importantly small polio outbreaks – not due to the wild type, circulating viruses, but to a vaccine-derived virus. It has long been recognized that the attenuated live virus used for oral vaccine had the rare potential to revert –by a naturally occurring, tiny genetic change– to neurovirulence, capable of creating a clinical disease indistinguishable from wild type polio. These outbreaks have been identified and responded, but must also be prevented.
The global programme has achieved not only the capacity to vaccinate hundreds of millions of children through routine immunization systems and targeted campaigns, but also a transformative data collection system
Currently, the Polio Endgame Strategy 2019-2023 is supplemented with an emergency plan to contain local outbreaks of vaccine-derived type 2 poliovirus. This has been necessary due to delays in access to the vaccine based on inactivated poliovirus that would have ensured that every child in the world had immunity to type 2 poliovirus, as the world pivoted to “Switch approach” to dropping the vaccine containing live attenuated viruses, since that strain was eradicated. Instead, 20 countries were not able to vaccinate with the necessary vaccine and in 2019 more than 350 cases of vaccine-derived polio cases were reported from 15 countries in Africa and South-East Asia.
Photo: UNICEF Ethiopia/2013/Sewunet.
The longer term outlook is a gift of investment in innovation: that is, even at this late stage in the eradication program, the potential for a new oral vaccine without the risk of reversion to neurovirulence, and which can be used broadly in the programs. This novel vaccine, also using live attenuated virus but with an increased genetic stability and therefore less risk for mutation, has been submitted for review under the World Health Organization’s Emergency Use Listing Procedure and may be available.
The history has not been straightforward, the delays to achieve the final target of polio eradication –originally set for the year 2000, new challenges have been identified, most importantly small polio outbreak– not due to the wild type, circulating viruses, but to a vaccine-derived virus
In parallel to this innovation comes recognition that the GPEI needs to improve its governance and gain in accountability, transparency, country engagement and integration. As stated by a recent governance assessment of the initiative released in July 2020, it is critical that GPEI leadership “demonstrate that change is welcome within the partnership because eradication goals may be at risk with the partnership’s current structure and practices.”
For those from global health looking for lessons from polio, we draw upon the following: the value of data and detailed understanding of new problems, the wisdom of sustained investments in innovative solutions, the importance of community engagement and ownership, and the understanding that governance and adaptations to new realities are crucial for success. With these in place, there is indeed optimism for near term success and sustainable solutions. And in global health, optimism is the secret ingredient to success.