RACHEL MARTIN, HOST:

It has been three years since India recorded at its last polio case. This achievement means the country can now be declared officially polio-free, a feat many health leaders felt was impossible just a decade ago.

As NPR's Michaeleen Doucleff reports, the same efforts to eradicate polio will help the country tackle an even bigger problem - measles.

(SOUNDBITE OF A CROWD AND TRAFFIC)

MICHAELEEN DOUCLEFF, BYLINE: It's a hot, dry day in the sprawling city of Moradabad, India. It's near the Nepalese border and the streets are packed. There's motorcycles, rickshaws and even a few horse-drawn carts.

(SOUNDBITE OF A CROWD AND TRAFFIC)

DOUCLEFF: But down a dark, narrow alley, the traffic fizzles out. And at the end, a group of parents is urging on a group of school kids. A boy in the front grabs the microphone.

UNIDENTIFIED CHILD: (Foreign language spoken)

CROWD: (Foreign language spoken)

DOUCLEFF: Go home to home, mother and father. Don't forget two drops of life, the kids shout out as they march down the alley.

They're announcing the start of a polio vaccination campaign. They're telling parents to bring their children to vaccine booths so they can get two drops of the oral vaccine. A local religious leader then reinforces the message.

UNIDENTIFIED MAN: (Foreign language spoken)

DOUCLEFF: Here's an important announcement, he says, Children up to age 5 will be given polio vaccine morning. Please give your children these polio vaccines.

UNIDENTIFIED MAN: (Foreign language spoken)

DOUCLEFF: Ten years ago, Moradabad was the world's epicenter for polio. But due to relentless vaccination campaigns, and a flood of money from international foundations, the region and India as a whole wiped out the virus in 2011.

DR. JAMES GOODSON: This was an enormous public health success. And it means that children and their parents no longer live in fear of that crippling disease in India.

DOUCLEFF: Dr. James Goodson is with the Centers for Disease Control and Prevention in Atlanta. He says that ending polio also means India, for the first time, has the tools and infrastructure it needs to go after other childhood diseases. At the top of the list - measles.

GOODSON: Because they were able to eliminate polio and see the success of that, they are now able to turn much more of their attention and focus toward eliminating measles.

DOUCLEFF: And measles is a big deal in India. An estimated 56,000 children died from the disease in 2011 alone. That translates to about 156 deaths each day.

GOODSON: Fortunately, the measles vaccine is one of the most effective and provides lifelong protection from the disease. But you do need two doses.

DOUCLEFF: And that's been the problem. Goodson says babies have traditionally gotten the first dose of the measles vaccine when they get their other shots. But the government just didn't have a way to reach all these kids twice, until now.

GOODSON: Polio eradication uses mass vaccination campaigns. These social networks of volunteers and some paid staff are very helpful for making sure that all children come to receive their vaccination during those campaigns. And so, now what we're seeing in India is that these networks are being retooled to fight measles, and to work towards measles elimination.

(SOUNDBITE OF A CROWD AND A CRYING INFANT)

DOUCLEFF: Back at the vaccination drive in Moradabad, the transition to fighting measles is already apparent. At one booth, health workers are giving babies two drops of the polio vaccine and then their second shot for measles.

Dr. Anisure Saddique directs the polio effort in the region for UNICEF. He says that stopping measles is going to be more challenging than polio.

DR. ANISURE SADDIQUE: Measles is not like polio because the vaccine is an injectable. Anyone just in half an hour training can administer polio vaccine. But for measles vaccinations we need trained manpower and these health worker within the government is limited.

DOUCLEFF: Nevertheless, Saddique says that India's success against polio has motivated local governments to train more people and ramp up health care.

SADDIQUE: This whole polio program, actually, it brought public health on the focus. All the health workers are known by the community so there's a huge demand.

DOUCLEFF: Many health leaders are starting to think that if a massive country like India can conquer polio, why not other diseases as well.

Michaeleen Doucleff, NPR News.