Two decades and billions of dollars later, India, along with all of Southeast Asia -- encompassing a fourth of the world's population in total -- is officially polio-free, the World Health Organization announced Thursday.
It's a major victory for India, which as recently as 2009 was home to half of the world's polio cases, as well as one of the biggest public health achievements in recent times.
CNN has more on how the milestone was reached in what was considered to be one the most difficult places in the world to eradicate the disease:
Health workers determined that the children of migrants or those growing up in difficult-to-reach areas were not getting access to vaccines. So they deployed immunization efforts to reach the most vulnerable, according to UNICEF. India launched a massive effort involving a surveillance network and almost 2.3 million vaccine administrators, who identified communities falling through the cracks.
To counter rumors and misgivings about the vaccine, social mobilizers, religious leaders and parents were included to increase understanding about immunizations.
They also bolstered communication and outreach efforts that often included Bollywood celebrities and cricket players. The efforts combined government, various U.N. agencies as well as philanthropic organizations.
In India, more than 170 million children are now vaccinated every year.
Just because a disease has been eradicated, though, doesn't mean it's gone. Polio remains endemic in Pakistan, Nigeria and Afghanistan; if we ease up on vaccinations, it could return. In an editorial for the Guardian Archie Panjabi, a polio eradication ambassador for Rotary International, warns:
We must ramp up our efforts in the endemic countries, because from them polio can re-emerge to infect children in places where it had been stopped, such as we saw last year in Syria and the Horn of Africa. If we were to relax our guard – decide, say, that the world could live with a few hundred polio cases a year and cease our mass vaccinations in at-risk countries – experts tell us polio could rebound with a vengeance, infecting thousands of children a year.