It’s not often an entire continent eradicates a disease, but on August 25, 2020, that happened when Nigeria was declared polio-free, clearing the virus from its last redoubt in all of Africa.

The person who did more than any other to drive polio to continent-wide extinction was Dr. Tunji Funsho, a former cardiologist and now the chair of Rotary International’s polio-­eradication program in Nigeria.

Funsho could have retired years ago, but in 2013, with polio still paralyzing children across Nigeria, he decided to step up to lead the Rotarians’ effort.

Together with the Bill and Melinda Gates Foundation, the WHO, the CDC and UNICEF, Funsho and Rotary helped lead National Immunization Days, getting millions of doses of the polio vaccine to children in cities and villages around the nation.

They also sponsored health-­education initiatives at community centers, mosques and even birthday parties.

This summer, the country marked four years without a case of wild polio, qualifying it for its polio-free certification, leaving Afghanistan and Pakistan as the only places in the world in which polio remains endemic.

“Certification will be an achievement,” Funsho told TIME in 2018. “But we’re not in a hurry for that. We’re in a hurry to make sure no child is paralyzed.”

In Nigeria and in Africa as a whole, that moment has arrived.