Polio

Our goal
To eradicate polio worldwide.
A polio vaccinator marks a young child in Karachi, Pakistan.
A polio vaccinator works in Karachi, Pakistan. ©Gates Archive/[Khaula Jamil]

At a glance

  • In 1988, when the Global Polio Eradication Initiative (GPEI) was launched, polio was present in more than 125 countries and paralyzed about 1,000 children per day. Thanks to immunization efforts that have reached nearly 3 billion children, the incidence of polio has decreased by 99 percent since then.
  • In 2020, the entire World Health Organization (WHO) African Region was certified free of wild poliovirus, four years after Nigeria—the last polio-endemic country in Africa—recorded its final case of wild polio. Today, wild polio is found only in Afghanistan and Pakistan.
  • Despite this progress, if we fail to completely eradicate polio, within a decade we could witness a resurgence of 200,000 new cases annually, making polio a critical priority in global health. The job is not done: Efforts must continue to stop wild polio and end all forms of poliovirus globally.
  • The foundation is a key supporter and partner of the GPEI.

The latest updates on polio

Our strategy

Our strategy

Polio eradication is a top priority of the foundation, and as a major supporter and partner of the GPEI, we contribute technical and financial resources to accelerate targeted vaccination campaigns, community mobilization, and routine immunizations. We also work with partners to improve polio surveillance and outbreak response; develop safer, more effective vaccines; and galvanize financial and political support for polio eradication efforts.

We have a unique ability to contribute to the fight against polio by taking big risks and making nontraditional investments. Examples include our investments in vaccine research and our establishment of emergency operations centers in Nigeria, Pakistan, and Afghanistan.

Children receiving oral polio vaccine at an event inaugurating a polio vaccination campaign in Kano, Nigeria
Children receiving oral polio vaccine at an event inaugurating a polio vaccination campaign in Kano, Nigeria.
Areas of focus

Areas of focus

By improving outreach, staffing, and data collection and analysis, polio vaccination campaigns can achieve the required immunization coverage to reach GPEI goals.

By improving outreach, staffing, and data collection and analysis, polio vaccination campaigns can achieve the required immunization coverage to reach GPEI goals.

Our priority is to improve the quality of campaigns in Afghanistan and Pakistan, as well as other countries where population immunity to polio is persistently low. With eradication in sight, it is more important than ever that countries sustain high-quality campaigns, even if they have no active polio cases.

The GPEI’s polio eradication strategy focuses on national and local campaigns in the highest-risk countries to provide all children with multiple doses of oral polio vaccine. Efforts include door-to-door immunization in areas where poliovirus is known or suspected, as well as in areas that have risk of reimportation, limited access to health care, high population density and mobility, poor sanitation, and/or low routine immunization coverage.

The GPEI is also implementing a comprehensive new strategy to stop the spread of circulating vaccine-derived polioviruses (cVDPVs)—rare forms of the virus that can occur in underimmunized populations. In partnership with affected countries, the GPEI aims to carry out more aggressive, higher-quality outbreak response and strengthen routine immunization in high-risk areas.

We support work to understand social, cultural, political, and religious barriers to improving vaccination coverage, and we seek ways to work with local political leaders and health professionals. We also focus on expanding staffing and training of vaccination teams, as well as providing technical assistance.

Nearly 20 million children worldwide do not receive all of the immunizations they need.

Nearly 20 million children worldwide do not receive all of the immunizations they need.

Reaching every community requires understanding local barriers to access as well as the use of mapping and planning tools. A coordinated immunization system can also serve as a platform for other important health interventions. We are working with our partners to strengthen routine immunization programs for polio and other preventable diseases, including diphtheria, tetanus, whooping cough, and measles.

It is essential to pinpoint where and how wild poliovirus is still circulating, and to verify eradication.

It is essential to pinpoint where and how wild poliovirus is still circulating, and to verify eradication.

A strong surveillance system enables accurately targeted campaigns, quick program adjustments, and swift response to outbreaks.

Polio surveillance is especially challenging because only a small percentage of infections result in clinically apparent paralytic disease. Confirming the disease requires analysis of stool specimens to see if poliovirus is present.

Through our investments to evaluate surveillance efforts in the highest-risk areas, we have discovered the need for improved environmental surveillance: testing sewage water samples for evidence of poliovirus transmission in the surrounding community. We have invested in a technology that promises more sensitive sampling with lower specimen volume, as well as more hygienic collection. We also fund efforts to develop less expensive and more reliable lab tools, such as a diagnostic kit that local labs can use to rule out negative samples and send positive specimens to reference labs for confirmation.

Although current vaccines and detection tools have proven highly effective in eliminating polio from most countries, they may not completely eradicate the disease.

Although current vaccines and detection tools have proven highly effective in eliminating polio from most countries, they may not completely eradicate the disease.

We are working with partners to improve existing tools while accelerating the development of safer vaccines, better diagnostic tools, new antiviral drugs, and other products. We also work with partners, suppliers, and governments to ensure sufficient vaccine supply and demand and to promote market competition.

The oral polio vaccine (OPV), which is most commonly used in the developing world, is safe, effective, easy to administer, and inexpensive. But this vaccine consists of live, weakened viruses, which in rare cases can revert to a form that can cause paralysis if allowed to circulate in an underimmunized community for a long time. In settings where there have been failures to reach all children with vaccines and raise immunity levels, OPV use poses a challenge to ending all forms of polio for good.

We are supporting the development of new oral polio vaccine formulations that do not pose this risk. In particular, we are working with partners to accelerate the development of novel oral polio vaccine type 2 (nOPV2)—a potential addition to the outbreak response toolbox. nOPV2 is a modified version of existing monovalent oral polio vaccine type 2 (mOPV2) that clinical trials have shown provides comparable protection against the poliovirus while being more genetically stable and less likely to regain strength and cause paralysis. In November 2020, nOPV2 was granted a recommendation for use under WHO’s Emergency Use Listing (EUL) procedure, with the initial rollout beginning as soon as early 2021.

We also assist in efforts to lower the cost of the injectable vaccine and implement the necessary training, supply, delivery, and communications infrastructure to expand its use.

Data collection and sharing are critical to eradicating polio. We work to improve data access to inform decision-making, track progress, improve environmental surveillance, and guide the development of vaccines and diagnostic tools.

Data collection and sharing are critical to eradicating polio. We work to improve data access to inform decision-making, track progress, improve environmental surveillance, and guide the development of vaccines and diagnostic tools.

We are also working with partners to develop a decision framework that identifies key decision areas, the data needed to inform decisions, and the staff and partners needed to analyze the data and create models. We support a data access platform at WHO that ensures key polio data are standardized, quality-assured, and available for analysis and decision-making.

Once wild poliovirus transmission has stopped globally, it will be important to ensure safe handling and containment of materials in laboratory and vaccine-production facilities.

Once wild poliovirus transmission has stopped globally, it will be important to ensure safe handling and containment of materials in laboratory and vaccine-production facilities.

Reintroduction of the wild poliovirus would present the potentially serious consequences of re-establishing the disease. As part of the GPEI, we are developing a post-eradication containment policy that will be adopted by the World Health Assembly.

In its two decades of operation, the GPEI has trained and mobilized millions of staff and volunteers, identified and reached households and communities that had been untouched by other initiatives, and established a robust global surveillance and response system.

In its two decades of operation, the GPEI has trained and mobilized millions of staff and volunteers, identified and reached households and communities that had been untouched by other initiatives, and established a robust global surveillance and response system.

Through polio eradication efforts, GPEI partners have learned how to overcome logistical, geographic, social, political, cultural, ethnic, gender, financial, and other barriers to working with people in the poorest and least accessible areas. The fight against polio has created new ways of addressing human health in the developing world—including through political engagement, funding, planning and management strategies, and research.

The GPEI has also developed a wide range of assets, including detailed knowledge of high-risk groups and migration patterns; effective planning and monitoring procedures; highly trained technical staff; local and regional technical advisory bodies; and commitments based on successful partnerships among global, national, religious, and local leaders. These assets have already been used to respond to other public health threats, including COVID-19, Ebola, meningitis in western and central Africa, H1N1 flu in sub-Saharan Africa and the Asian subcontinent, and flooding and tsunami disasters in South Asia.

We are continuing to work with the GPEI to identify ways in which the polio infrastructure—including supply chains, surveillance and laboratory systems, and social mobilization networks—can be used to support other health initiatives and immunization programs in the long term. Around the world, the GPEI is lending its infrastructure and expertise to protect the vulnerable from COVID-19. From Pakistan to Nigeria, the program is building on years of experience in fighting outbreaks to support countries in responding to the pandemic.

We work closely with GPEI partners to mobilize funding and sustained global and national political momentum for polio eradication.

We work closely with GPEI partners to mobilize funding and sustained global and national political momentum for polio eradication.

This involves promoting efforts to increase polio funding from government donors and cultivating new and nontraditional donors. We also encourage leaders of polio-affected countries to follow through on their commitments to ongoing campaigns, and we help them identify and implement sources of financing for those campaigns.

We also align and mobilize other advocates, including influential community members such as religious leaders, volunteer organizations, and employers. With partners such as Rotary International; WHO; United Nations Children’s Fund (UNICEF); Gavi, the Vaccine Alliance; RESULTS; the UN Foundation; and Global Citizen, we use traditional and social media to raise awareness of polio eradication and immunization activities in both donor countries and countries where polio is a threat. We support efforts to tailor communications to particular social, cultural, and political contexts to build demand for vaccination and dispel myths about the safety and efficacy of vaccines.

Why focus on polio?

Why focus on polio?

Over the past three decades, the world has made tremendous progress toward eradicating polio. In 1988—when wild poliovirus was present in more than 125 countries and paralyzed 350,000 people every year, most of them young children—the World Health Assembly set a goal to eliminate the disease, and the GPEI was launched. Since then, immunization efforts have reduced the number of cases by more than 99 percent, saving more than 18 million children from paralysis. Today, wild polio is found only in Pakistan and Afghanistan.

Despite this progress, several challenges remain in reaching all children with vaccines. Wild poliovirus continues to circulate in parts of Pakistan and Afghanistan, and outbreaks of circulating vaccine-derived poliovirus (cVDPVs), a rare form of the virus that can emerge in underimmunized communities, are ongoing in parts of Africa and Asia. Efforts to reach unvaccinated children are often hampered by poor campaign quality, weak routine immunization, massive mobile populations, and insecurity. If we fail to eradicate this highly contagious disease, within a decade we could witness a resurgence of as many as 200,000 new cases annually.

At the World Health Assembly in 2012, 194 member states declared the eradication of polio a “programmatic emergency for global public health.” While eradication has taken longer than originally hoped, the GPEI and its donors are committed to overcoming the remaining challenges to eradication and ending all forms of the poliovirus for good. At the 2019 Reaching the Last Mile Forum in Abu Dhabi, donors pledged US$2.6 billion to support the program.

Experts estimate that eradicating polio would generate US$14 billion in cumulative cost savings by 2050 when compared with the cost to countries of controlling the virus indefinitely. This figure does not include additional health improvements resulting from other GPEI efforts, such as vitamin A supplementation or the much larger net benefits of eradication for countries that eliminated polio before the GPEI was launched.

In August 2020, the WHO African Region was officially certified free of wild poliovirus after Nigeria—the last polio-endemic country in Africa—recorded its final case of wild polio in 2016. This incredible public health achievement was the result of a decades-long effort across 47 African countries involving millions of health workers, innovative strategies to vaccinate children amid conflict and insecurity, and a huge disease surveillance network to test cases of paralysis and check sewage for the virus.

Bill Gates talks with polio survivors. Watch the full video here.

Global collaboration and innovation have produced new tools and approaches that can help improve logistical planning for polio eradication. In addition, refinements to the polio vaccine have improved the immune response to the remaining types of the disease. Today, only one strain of wild poliovirus (wild poliovirus type 1) remains in circulation. Wild poliovirus type 2 was declared eradicated in 2015, and wild poliovirus type 3 was declared eradicated in October 2019. New diagnostic, monitoring, and modeling tools are allowing faster and more accurate tracing of polio cases and transmission patterns.

To slow the spread of polio in their countries, Pakistan and Afghanistan have implemented national emergency plans overseen by their heads of state. These programs increase accountability and improve the quality of polio vaccination campaigns from the national to the local level. WHO is providing unprecedented levels of technical assistance to these countries, and improved vaccination campaigns are helping to reach more children.

Strategy leadership

Strategy leadership

Our partners

Our partners

We do our work in collaboration with grantees and other partners who join with us in taking risks, pushing for new solutions, and harnessing the transformative power of science and technology. 
Gavi, the Vaccine Alliance
Global Citizen
Global Polio Eradication Initiative (GPEI)
Rotary International
United Nations Children's Fund (UNICEF)
United Nations Foundation
United States Centers for Disease Control and Prevention
World Health Organization (WHO)