Reprinted with permission from Foundation Blog, The official blog of the Bill & Melinda Gates Foundation

By: Dr. Tadataka Tachi Yamada

When I was growing up in Japan, my close friend Keichi Maruyama, who lived right next door to me, was crippled from polio.

Most people today are too young to remember, but it was a disease that struck fear into every family. We knew it could hit home at any time.

Dr. Tadataka Tachi Yamada watches as a boy receives a polio vaccination at Bhairon Mandir Temple. Tachi was there to understand the importance of transit and migratory populations in contributing to polio transmission. New Delhi, India. April 5, 2009. Photo courtesy of the Bill & Melinda Gates Foundation / Prashant Panjiar.

Polio is no longer a threat in most of the world, thanks to a polio vaccine and an enormous global commitment. We are now locked in a mortal battle to completely eradicate the disease and have reduced the fight to just four countries – Nigeria, India, Afghanistan, and Pakistan.

This week I attended a symposium to commemorate the 30th anniversary of smallpox eradication. Thanks to the development and delivery of a vaccine, we achieved one of the greatest global health victories of all time. Vaccines are the most important and cost-effective intervention available to prevent illnesses and death.

I believe the fundamental lessons from smallpox can be applied to many diseases, especially the fight against polio. We need political will, sufficient human and financial resources, and ongoing scientific innovation

Of course there will be challenges along the way. I think the biggest lesson from the smallpox success is that we must approach each new challenge with the spirit of continuous learning and be flexible enough to adjust along the way. We must do the same until the world is polio-free, so that our children’s children will never have to say: “You came this close and gave up.”

Dr. Tachi Yamada, president of the foundation’s Global Health Program, leads the foundation’s efforts to help develop and deliver low-cost, life-saving health tools for the developing world. He oversees Global Health’s grantmaking, which focuses on four major activities: discovery, development, delivery, and advocacy.