WHO changes tactics in polio eradication effort

Instead of conducting 266 huge immunization campaigns in 93 countries as it did last year, the World Health Organization and partners in the Polio Eradication Initiative in the next year will launch 51 campaigns in only 13 countries: the seven where polio cases still occur — India, Nigeria, Pakistan, Egypt, Afghanistan, Niger and Somalia — and six considered at high risk of re-infection with the paralyzing disease — Angola, Bangladesh, Democratic Republic of the Congo, Ethiopia, Nepal and Sudan.

"What we are doing is freeing up 300 million doses of vaccine and $40 million in resources and putting them into the remaining infected areas," says WHO's Bruce Aylward, who coordinates the initiative.

If successful, it will be the first eradication of any disease since smallpox in 1980.

The plan has risks. By halting mass campaigns, in which volunteers seek out every child in a region over a period of days, there is a possibility that polio could be imported back into an area that is now polio-free. To head that off, local health authorities will pay extra attention to routine immunization and enhanced global surveillance so if a case does occur, health officers can react quickly to isolate the victim and vaccinate everyone who could have been exposed to the virus.

Since the initiative began in 1988, 209 countries have been declared free of polio; annual cases have dropped from more than 350,000 in 125 countries to 1,919 last year in seven countries.

Global certification by WHO will take two to three years beyond the last case to assure that any virus samples remaining in laboratories are secure and accounted for.

There is less concern that polio could become the same kind of bioterrorism threat that smallpox is, Aylward says, because it is not airborne; it is passed through the fecal-oral route. Only one in 200 people who are infected with polio become paralyzed, and of those, 10% die.