Watch TIME’s Jeffrey Kluger Discuss How to Eradicate Polio

Since the development of the first polio vaccine in the 1950s, the number of cases of the devastating disease has been reduced by 99 percent. But despite that extraordinary progress, people in three countries still suffer from polio. Now, Rotary International, along with the World Health Organization, Centers for Disease Control and Prevention and UNICEF have brought the world tantalizingly close to eradicating the virus for good.

In recognition of World Polio Day, watch as TIME editor-at-large Jeffrey Kluger moderates Rotary’s live-streamed event in Chicago, on Friday at 7:30 PM, EDT.