Polio Eradication and Beyond: What the Polio Endgame Means for Public Health

The end of polio is in sight, with fewer cases of wild polio virus being reported yearly. Today, polio is on the cusp of eradication, with cases in only a few high-risk areas of three countries—Afghanistan, Nigeria, and Pakistan. This brings the eradication effort to its final chapter, otherwise known as the polio endgame. The successful elimination and eventual eradication of the remaining wild polio viruses is related to the efforts of effective global, regional, and local partnerships. As a result of these partnerships, eradication of polio means much more for global public health initiatives than the end of this debilitating disease. The release of the “Polio Endgame and Legacy: Implementation, Best Practices, and Lessons Learned” supplement for The Journal of Infectious Diseases provides a valuable record of the collaborative experiences and lessons learned from these partnerships during the polio endgame. Specifically, the supplement provides a straightforward assessment of successes and shortfalls of the endgame activities, and provides further insight into the synergistic relationship between polio eradication efforts and immunization systems around the world.

Three wild polioviruses cause paralytic polio—types 1, 2, and 3. In 2015, the Global Commission for the Certification of the Eradication of Poliomyelitis certified the eradication of type 2 poliovirus, making it the first human pathogen to be eradicated since smallpox. The absence of type 3 poliovirus worldwide since November 2012, and limited presence of type 1 poliovirus in only a few geographic areas of three countries, meant that partners needed to implement endgame activities for polio eradication. After eradication, the routine use of oral polio vaccine (OPV) must end to avoid cases of paralysis related to the vaccine. Stopping OPV use would begin with removing the component for type 2, which has been eradicated, from the OPV. Ultimately, OPV would no longer be used after eradication of the remaining two polioviruses. At the same time, the world would shift to the use of an injectable, inactivated polio vaccine (IPV), which does not cause vaccine-derived polio and provides some protection against all three polioviruses. The duration of use of IPV remains to be determined, but it would continue at least until all polioviruses are effectively contained worldwide.

Responsibly transitioning polio resources, infrastructure, and experience is also a core component of the endgame. The polio eradication program is not a typical vertical program—polio resources and infrastructure fill in many gaps in the immunization systems that protect hundreds of millions of children from vaccine-preventable diseases (VPDs) worldwide each year. After eradication, these polio resources will undoubtedly decrease, potentially leaving children vulnerable against VPDs such as diphtheria, hepatitis, measles, rubella, and whooping cough, against which great strides have been made in recent decades. Documenting these synergies and strengthening immunization systems in countries with extensive polio resources is a critical component of the polio endgame in continuing those sustainable gains to improve children’s health after polio resources disappear.

Although strategic planning of activities is crucial, the ability to execute those plans decisively reflects the importance of effective global, regional, and local partnerships. Because of strong partnerships, 155 countries and territories switched from trivalent OPV (containing types 1, 2, and 3 poliovirus) to bivalent OPV (containing types 1 and 3 poliovirus) during a two-week period in 2016. Over 100 countries introduced IPV within a two- to three-year period, making it the fastest rollout of a new vaccine in history. This achievement can now serve as a model for other vaccine introductions, especially in an accelerated context.

The successes of the polio endgame were rooted largely in transparent communication, effective delivery of available technology to target populations, and leveraging of political will. Communication has been key to the polio program over the years, allowing the rapid exchange of information and ideas, and leading generations of trust and consensus among partners, stakeholders, and countries. During the endgame, the maturity of the program has been at its peak, enabling the implementation of complex tasks such as the synchronized global OPV switch and the accelerated introduction of IPV, a vaccine new to developing country programs but available to the world since early 1960s. Ultimately, it was the political will to finally reach the goal of polio eradication that motivated national programs to prioritize these polio endgame activities. It is hopeful that this political attention to the polio endgame has encouraged the strengthening of national immunization programs, which prevent two to three million childhood deaths each year. With functioning, accountable programs that are adequately resourced, many more lives could be saved.

Polio eradication efforts are an example of global public health at its best. These efforts have been successful in large part due to the collaborative strengths of the partnerships. These collaborations are not only among institutions, stakeholders, and nations, but also among dedicated individuals at all levels, from the millions of volunteer vaccinators worldwide to health workers, program managers, scientists, and policymakers who have mobilized to eradicate polio. The supplement highlights the enormous successes of this close global collaboration in public health. The end of polio certainly seems to be near. However, more collaborative efforts must follow—VPDs continue to kill non-immunized children in the poorest countries worldwide. Immunization systems that prevent these diseases are aging and need upgrading. Articles in the supplement pointedly state that countries and partners have heavily leveraged their polio resources and infrastructure to temporarily support these systems. The disappearance of these polio resources could have devastating effects to immunization systems with worldwide ripple-effect consequences. The articles in the supplement collectively document and celebrate the successes of the endgame. At the same time, they plot out a cautious way forward by strongly emphasizing the need to responsibly transition polio resources to maintain and strengthen immunization systems that could immeasurably suffer with declining polio resources and infrastructure. The supplement is a cautious reminder that now is not the time to relax. Eradication of polio is but a chapter in long-running efforts to reduce death and disability from all VPDs and to provide healthier lives for children worldwide.

Related Links:

To read the full Journal of Infectious Diseases supplement “Polio Endgame and Legacy: Implementation, Best Practices, and Lessons Learned”: https://academic.oup.com/jid/issue/216/suppl_1

For more information about the change in poliovirus vaccines and strengthening routine immunizations visit World Health Organization, An Overview of Objective 2 of the Polio Endgame: http://www.who.int/immunization/diseases/poliomyelitis/endgame_objective2/en/

For more information about the CDC’s role in polio eradication: https://www.cdc.gov/polio

For more news stories highlighting the partnerships involving the Global Polio Eradication Initiative: http://polioeradication.org/news/news-stories/