Global Polio Largely Fading
Monday, December 26, 2005
The 17-year effort to eradicate polio from the world appears to be back on track after nearly unraveling in the past three years.
A new strategy of using a vaccine targeting the dominant strain of the virus appears to have eliminated polio from Egypt, one of six countries where it was freely circulating. That approach is on the verge of doing the same in India. Twenty-five years ago, India had 200,000 cases of paralytic polio a year. A decade ago, it was still seeing 75,000 cases annually. Through November this year, it recorded 52.
Such dramatic successes, many the result of a more potent formulation of polio vaccine, have once again made eradication of the paralyzing viral disease a realistic goal. Only one human disease -- smallpox -- has ever been wiped out, and that was almost three decades ago.
Intensive immunization campaigns targeting tens of millions of children in Africa have suppressed polio transmission in countries where it reappeared after the continent's most populous nation, Nigeria, halted universal polio vaccination in 2003.
The end of 2005 had been the latest deadline for polio eradication. The initiative, started in 1988, had a polio-free world by 2000 as its goal. No new deadline has been set, and success may depend, in part, on raising $200 million for more vaccination campaigns.
Nevertheless, the organizers and those funding the eradication initiative are more confident.
"I don't think there's any question that it's going to succeed. The question is how long," said William T. Sergeant, a Rotary International official. "The countries that were reinfected -- they were places where we had stopped polio before, and we can stop it again."
A civic club with 33,000 chapters worldwide, Rotary is a co-leader of the eradication campaign, to which it has contributed $600 million and tens of thousands of volunteers.
"The risk now is Nigeria -- and losing the commitment in other countries. But we're confident now that Nigeria will get the job done," said David L. Heymann, chief of the polio eradication program at the World Health Organization, which is directing the initiative.
The new "monovalent" vaccine appears to have been close to a magic bullet in boosting immunity to polio in a half-dozen areas of extremely high population density.
"This is the big development, without a doubt," said R. Bruce Aylward, a Canadian physician and WHO's chief eradication strategist.
The effort to eliminate polio has taken longer and proved harder than the eradication of smallpox, which took 10 years and ended in 1978. One of the main reasons is that most polio infections are not apparent, while smallpox causes a dramatic rash that makes identifying victims fairly easy.