Today marks a poignant anniversary: it has been three years since the last case of polio was reported in India. Just five years ago, India was home to almost half the world's new polio cases. But thanks to a massive vaccination program, there have been zero new cases in India since January of 2011—and that's a huge victory for children in India and surrounding countries.

To mark the occasion, here's a trip to the last polio ward in India:

In a blog post this morning, Bill Gates explained why this anniversary matters, writing:

India’s victory galvanized the global health community to commit to achieving a polio-free world by 2018. Now, we only have 3 more countries to go, down from 125 in 1988. All three countries face unique challenges that make eradication difficult, but India’s success gives the polio program valuable lessons to apply in the remaining countries and confidence that eradication is possible.

While we're on the topic, who is India's last polio patient? She's a little girl named Ruksar. Here she is, sitting with Ramesh Ferris, one of five inspiring people living with polio: