Whenever someone asks me why I believe it’s possible to eradicate polio, I tell them about my 2010 trip to India to visit one of the country’s lowest castes—the Musahar.
Today, India is polio free. But less than a decade ago, more than half the world’s cases of polio could be found in India. At the time, many health experts said that India would be the last place on Earth to stop polio because its high birth rate, poor sanitation, and population density allowed the disease to flourish.
So how did they wipe out the disease?
The answer can be found in the remote marshlands of the Kosi River in the Indian state of Bihar. The region is home to one of the poorest, most underserved castes in India, the Musahar. In 2010, vaccinating the Musahar and other people living in remote, high-risk areas was one of the biggest obstacles India faced in its long campaign to end the paralyzing disease. Thousands of children were being missed during the national immunization drives, allowing the disease to continue to spread.
In response, the Indian government launched an all-out effort to reach every child, employing a new communication campaign to mobilize support for polio immunization and better maps to ensure that no family was missed. They deployed more than 2 million vaccinators who covered every speck of the country, including the Musahar village I visited, which was often inaccessible because of flooding from the Kosi River. (One of the most inspiring photographs of that time was an image of polio workers wading waste deep in water to reach remote villages with the polio vaccine.)
By 2014, India achieved its goal of being polio free, proving that the paralyzing disease could be defeated in the most complicated circumstances. With new ties to even the remotest communities, health workers are providing children with much more than the polio vaccine. They continue to work with local communities to improve the delivery of other critical health services, including maternal and newborn care, as well as vaccinations for measles and other preventable diseases.
India’s experience continues to be an inspiration for the world’s final push to wipe out polio in the three countries where it endures: Afghanistan, Pakistan, and Nigeria. Based on the latest figures, in 2017, there were just 21 identified cases of wild poliovirus in the world—the lowest number ever—down from 350,000 cases per year when the global polio eradication effort launched in 1988.
That’s an incredible achievement. But now is no time for complacency. If polio is a threat anywhere in the world, it is a threat to us all. That’s why it’s more important than ever for the world to continue to support the millions of vaccinators who are working tirelessly to finish the job. Their dream, as is mine, is to see the day that polio is defeated.
(This originally appeared on gatesnotes.com.Written by Bill Gates ; Co-chair, Bill & Melinda Gates Foundation)