TORONTO - India has been polio-free for three years, an accomplishment that will lead to the formal dropping of the nation from the list of polio-endemic countries.
The milestone is of major significance both for the country and for the global effort to drive polio from the world.
For many years, critics argued stopping polio transmission in the South Asian country was not an achievable goal. High levels of poverty in densely populated cities with poor sanitation created a niche in which the wily virus flourished. Even diehard supporters of the Global Polio Eradication Initiative were at times unclear how to crack that nut.
"This was the one that everyone said could never be done," says Dr. Bruce Aylward, the World Health Organization's top person for polio eradication.
Three countries remain on the endemic list: Pakistan, Afghanistan and Nigeria. Endemic countries are those where circulation of polio has never been halted. In addition, re-ignited transmission in war-torn Syria and Somalia are posing serious difficulties for the eradication program.
The current goal for stopping transmission is the end of 2014. Aylward said the fate of that deadline hinges on Pakistan, where fatal attacks on polio campaign workers have occurred in one part of the country and another refuses to allow vaccinators access to its children.
In addition to those problems and ongoing transmission within its borders, viruses from Pakistan keep polio alive in Afghanistan, and have been found in Syria, Egypt, Israel and the Palestinian territories, Aylward said.
As for India, formal confirmation of the country's polio-free status will come in late March, when the certification commission for the WHO's South-East Asia Region operation, SEARO, will meet to review 36 months worth of laboratory data for India dating from the last case, which was diagnosed on Jan. 11, 2011, Aylward said.
When India is dropped from the endemic countries list, the entire SEARO region will be polio-free — a development that will mean three-quarters of the world's population live in regions where polio no longer circulates, said Aylward, who is the WHO's assistant director-general for polio, emergencies and country collaboration.
The WHO is one of four founding partners in the effort to rid the world of polio. In 1988, the WHO, UNICEF, the U.S. Centers for Disease Control and the service club Rotary International embarked on the effort with a goal of stopping polio transmission by the turn of the millennium. Later, the Bill and Melinda Gates Foundation joined the partnership and have made polio eradication its top priority.
"It was a very difficult push and I think a lot of people back in those days thought: 'We're never going to do it,'" said Dr. Jay Wenger, head of the polio program at the Gates Foundation.
"But the fact that India pulled together and galvanized the entire country, really from the government on down, to over two million people every NID (National Immunization Day) that used to go out and vaccinate kids across the country, that huge push really succeeded."
"And I think that the fact that it did really was proof of principle that we can eradicate polio from the world, if we can do it in a place like India."
Wenger, who worked on polio eradication in India from 2002 to 2007, said the campaign there had to think outside the box to overcome significant challenges.
When it was determined the three-strain oral vaccine wasn't working as well as it needed to, a two-strain version was developed. The realization that the children of migrant workers were being missed by vaccination efforts — and were moving the virus around the country — led to an enormous effort to track migrant populations in the country.
"I think it's an interesting note that the Indian effort to get rid of polio was a big adventure in innovation. The program would look and say 'OK, what is the problem? What are ways to get around it?'" Wenger said, adding the lessons learned in India are helping other countries combat polio.
"The program did many, many things which have sort of opened up new ways to get rid of the virus in other places."
The current goal for stopping transmission is the end of 2014. Aylward said the fate of that deadline hinges on Pakistan, where fatal attacks on polio campaign workers have occurred in one part of the country and another refuses to allow vaccinators access to its children.
Aylward said the single biggest risk to reaching its year-end goal of stopping transmission is Pakistan.
"If Pakistan doesn't start vaccinating in all affected areas, doesn't stop shooting vaccinators, it can't meet the target. You've got to be vaccinating."
The ultimate goal of the polio eradication program is to have the world declared polio-free in 2018. That gives the program a little wiggle room at this point. Certification of polio-free status requires three years without a polio case, so if transmission is stopped in 2015, the 2018 deadline can still be reached.
"It is a big challenge," Wenger admitted. "(But) we believe that we're still on track to be able to make it by 2018."