By David Brown
Washington Post Staff Writer
Thursday, January 22, 2009
The global effort to eradicate polio, which began more than two decades ago and has suffered repeated setbacks, will receive an additional $635 million in an effort to finish the job over the next five years.
The money will be used to intensify vaccination campaigns in northern India and northern Nigeria, the two regions that account for more than 80 percent of the remaining cases of the paralyzing infection. In addition to those two countries, Pakistan and Afghanistan are the only others where "wild" polio virus still circulates.
Providing the new infusion of cash are Rotary International, the service organization that first proposed the eradication of polio and has raised $825 million toward the goal; the Bill and Melinda Gates Foundation; and the governments of Germany and Britain.
About $6.17 billion has been spent so far on the eradication effort. The United States has contributed $1.4 billion over the years and is the biggest single donor.
"If we don't do this, we will lose all the investment we have made in the past," Gates said yesterday at a Rotary conference in San Diego.
The $255 million Gates pledged comes 14 months after a $100 million donation his foundation made in 2007 as the virus resurged in India. Since then, he and his wife have committed themselves to eradicating malaria, a task that will be much harder than ending polio.
Yesterday, Gates suggested that a failure to rid the world of polio would be a major setback to progress in global public health that his foundation is spearheading.
"The value of this eradication initiative in energizing the global health movement can't be underestimated," he said. "It is super-important that we succeed with polio."
Some experts, however, have come to doubt that polio eradication is possible. The campaign has already missed two deadlines, in 2000 and 2005.
The number of cases worldwide last year was 1,625 -- about 500 more than in 2007 and three times the number in 2001, the best year of the campaign. Nevertheless, the incidence of the disease has been cut by 99 percent since the campaign began in 1988, when about 350,000 cases a year were recorded.
On a teleconference with reporters yesterday, the coordinator of the campaign at the World Health Organization said that failing to finish the job would result in returning to something close to the previous level of infection.
"This is an epidemic-prone disease," said R. Bruce Aylward, a Canadian physician and epidemiologist. "The idea that it can be controlled at the level where it is now is a false premise."
There are many reasons why eradicating polio has proved harder than eradicating smallpox, a unique achievement that was officially completed in 1980.
One is that the vast majority of polio infections are "silent," with about 1 in 200 causing paralysis. That means the virus can spread widely before authorities realize it is present in a population. Another is that there are three types of polio virus, and eradication must eliminate all of them.
The vaccine used in the global campaign consists of versions of all three strains that have been weakened so they cannot cause illness. After the vaccine is administered, the viruses briefly grow in a person's intestinal tract, providing immunity and, for several weeks, also being excreted in feces.
That can spread the "vaccine-derived" strains through an under-immunized population, and over time the virus can revert to a pathogenic form and cause paralysis.
That is what is happening with so-called type 2 polio virus. Its wild form was eradicated in 1999, but since then a vaccine-derived type 2 virus has caused more than 100 cases in northern Nigeria, where in some locales fewer than 60 percent of children are fully immunized.
Earlier this decade, several Nigerian states stopped mass immunization for more than a year because of internal political rivalries and suspicions about the vaccine's safety. Polio cases rose steeply, and travelers carried the disease to 20 previously polio-free countries, necessitating expensive and laborious efforts to stamp it out again.
The Gates foundation will provide $255 million over the next five years. Rotary will match that with $100 million. The organization, which has 33,000 clubs around the world, has raised $61 million of a $100 million pledge to match the Gates's 2007 donation.
Britain, the second-biggest governmental donor to polio eradication, pledged $150 million, and Germany, the fifth-biggest contributor, pledged $130 million.
Although no new deadline has been set, WHO has a plan for using the money over the next five years, during which it hopes eradication will be achieved.