Since 1988, global efforts to eradicate polio have reduced the number of new cases by 99 percent, from 350,000 annually to a few dozen this year — preventing lifelong paralysis in millions of children worldwide.
In the fight to extinguish the disease, a significant milestone was reached on July 24. It has now been one year since the last reported case of wild polio in Nigeria.
Historically, Nigeria has been the main virus reservoir responsible for repeated outbreaks across the world. Just three years ago, the country seemed to be struggling in the battle against polio and recorded more than half of all global cases.
This achievement is the result of a Herculean effort to reach every child multiple times with the polio vaccine — thanks to the legions of volunteers, health workers, community leaders, mobilizers, lab staff, religious and traditional leaders, and millions of others.
However, since the wild polio virus can circulate silently, hiding in raw sewage for more than three years, it is far too soon for Nigeria to be complacent. The risk of undetected transmission remains in Nigeria and other vulnerable areas in and around conflict zones in Africa.

A health worker administers a polio vaccine to a girl in Nigeria. / Courtesy of TSCHIP
What is polio?
Poliomyelitis (polio) is a highly infectious disease caused by the wild polio virus. It spreads through contact with the stool of an infected person and droplets from a sneeze or cough. It invades the nervous system, and can cause paralysis or even death in a matter of hours. For thousands of years, polio was a leading cause of disability, arriving without warning and causing lifelong paralysis.
When will Africa be certified polio-free?
At least two more years must pass without a case of wild polio virus in Africa for the World Health Organization (WHO) to certify the region as polio-free. This will require continued government leadership across the African region, particularly in Nigeria, high quality immunization campaigns, and improved routine immunization, monitoring, and sustained vigilance.
We don’t want any cases of polio to go unnoticed or unreported. If Nigeria sustains high quality campaigns — maintaining population-level coverage (at least 90 percent of people), even in remote and hard-to-reach areas — and continues to improve routine immunizations, the virus will be stopped. Eradicating polio in all of Africa will bring us closer than ever to a world without the disease.
When will the world be polio-free?
Polio will be stopped — but we need continued political will, quality immunization campaigns, stronger routine immunization, and active disease surveillance to make that happen. The world will be declared polio-free three years after the last polio case is identified.
What is USAID’s role in the global polio eradication effort?
The global effort to eradicate polio is spearheaded by Rotary International, the Centers for Disease Control and Prevention (CDC), WHO, UNICEF and the Bill and Melinda Gates Foundation.
USAID has played a critical role raising the importance of cross-border coordination, communication and the need for more women vaccinators. In fact, by working with local community organizations, women’s groups and self-help groups, the messages have gone well beyond polio to address other immunizations, water and sanitation, breastfeeding and handwashing.
Supported by USAID, countries are monitoring for cases in formal health facilities and in communities, providing the data to verify that immunization efforts are working. Increasingly, this network of disease surveillance officers is also searching for cases of other preventable diseases and working at the front lines during any disease outbreak or natural disaster. Our steady financial support and technical leadership has contributed to this success and laid the foundation for a lasting legacy.
How important are vaccines to global health?
Vaccines are one of the best buys in public health and global development — the cheapest, most lasting measure we have to save a child’s life. Vaccines protect us from 25 diseases, such as measles, whooping cough, polio and meningitis, and avert an estimated 2 to 3 million deaths each year.
Working closely with host country governments, ministries of health and finance, and in-country and global partners, USAID is bringing its financial, technical and diplomatic efforts to support country immunization programs and reach all children with critical safe vaccines.
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RELATED LINKS:
- Check out more of USAID’s work in global health
- Follow @USAID and @USAIDGH
- Follow the conversation at #endpolio