A boy in Firozabad, Uttar Pradesh, India, shows his finger, painted to indicate he has just been vaccinated. Financial support for work that included this photograph came from the Pulitzer Center for Crisis Reporting. Image: Helen Branswell
In the mid-2000s, when scientists questioned whether the campaign to rid the world of polio could succeed, skeptics pointed to a problem that some called PAIN.
That stood for Pakistan, Afghanistan, India and Nigeria—the four countries that were stubbornly standing in the way of success. The four had never managed to stop the spread of polioviruses within their borders and continued to send viruses, like embers off a fire, to re-ignite outbreaks in places that had previously halted transmission.
Now it appears someone's going to need to craft a new mnemonic.
India, which once seemed likely to be the last country on Earth to rid itself of polio, appears to have succeeded ahead of Pakistan, Afghanistan and Nigeria in besting the crippling viruses. The last child paralyzed by polio in India got sick on January 13, 2011, and surveillance for wild polioviruses in sewage has not turned up the pathogen in more than a year.
If India produces 12 straight months of polio-free surveillance data, it will be removed from the list of countries where polio is considered endemic, leaving only the other three. A statement hailing that likely eventuality will be issued by the Global Polio Eradication Initiative on the one-year anniversary of the last case later this week. But with the time it takes to process pending laboratory tests, it may be mid-February before there is official word.
Still, there is the sense that India is on the threshold of a momentous achievement, one gained against tremendous odds.
"This is huge for us. It has taken more than a decade and tens of millions of health-workers, managers and a lot of mobilization to get to this point," says Hamid Jafari, project manager for the World Health Organization's National Polio Surveillance Project, based in New Delhi.
After more than a decade battling the virus, and heartbreaking years of seeing the numbers of paralytic cases dip tantalizingly low, only to rebound, some scientists doubted polio could be stopped in India. It was commonly observed that the eradication program had two distinct problems: In Nigeria, where some Muslim parents refused to vaccinate their kids on religious grounds, and in conflict-torn countries like Afghanistan, where safe access is a challenge, the programs were failing to vaccinate all children. In India, however, the failure was on the part of the vaccine.
Where children are well nourished and healthy, three doses of oral polio vaccine will do the trick. But malnourished children who live where sanitation is poor and diarrhea is a fact of daily life cannot mount a protective immune response so easily. In India children who had been vaccinated eight, 10 or more times would sometimes still fall prey to polio.
New vaccines that targeted first one and later two strains of polio, rather than all three, were introduced and began to make real inroads. But the country still faced enormous challenges. In India locating and vaccinating all the vulnerable children is a gargantuan task. In the two poor northern states where polio made its last stand—Uttar Pradesh and Bihar—more than half a million babies are born every month. On the twice-annual national vaccination days, 2.3 million vaccinators visit 209 million households.
"We have to get to these children, these newborns, with vaccine faster than the wild virus can get to them. It's a race against virus," Jafari explains.
In addition to introducing more effective vaccine, India got better at finding high-risk children, homing in on families that move about the country looking for seasonal work. Transit points—train stations, bus depots, busy highway intersections—are used as distribution centers during vaccination campaigns. And special efforts are made to locate and map where migrant families set up camps, to ensure their children are not missed when vaccination teams make their rounds.