(FORTUNE Magazine) – In the past year members of the Rotary Club in Sedalia, Mo. (pop: 20,339), honored a student of the month at Smith-Cotton High School, read to first-graders, delivered valentines to patients at Bothwell Regional Hospital, and helped the city's Hispanics celebrate Cinco de Mayo. Also, they kept working to eradicate polio worldwide.

Well, the Sedalia club isn't eradicating polio all by itself--30,000 Rotary Clubs all over the world are helping--and the job's not quite done. Polio still exists in seven countries: Afghanistan, Egypt, India, Niger, Nigeria, Pakistan, and Somalia. But the incredible fact is that Rotary International, the butt of stand-up comedians forever, has since the mid-1980s all but wiped out the disease. When Bill Gates, whose Bill and Melinda Gates Foundation has given billions to advance world health, is asked what medical projects he respects, he often starts with Rotary and "the remarkable job it has done with polio."

Years ago every Rotary Club was an island that carried out service projects on its own. It would have been "close to heresy," says Bill Sergeant of Knoxville, Tenn., now Rotary's poliomeister, for anyone to suggest any other form of operating. But in the late 1970s a visionary Rotary president, Australian Clem Renouf, persuaded the organization's hierarchy that the clubs were wasting their talents by not uniting to attack a major problem. Polio was chosen, and ultimately, in 1986, Rotary announced a drive to raise the unimaginable amount of $120 million to eradicate the disease. With that start--and with the $247 million that was actually raised--PolioPlus was off the ground.

Rotary has now put more than $500 million into PolioPlus and has gathered billions more from such partners as the World Health Organization, Unicef, the Centers for Disease Control, and the Gates Foundation itself. Vaccines are the first cost, of course. Every child under the age of 5--there are 607 million in the world--needs to receive at least six doses, at a per-dose cost of around 10 cents. Beyond that expense is the logistical challenge of delivering the vaccines. The difficulty of getting desperately poor mothers and children to an immunization center six or more times can't be underestimated. Rotary takes on much of that work: In war-ravaged Sudan, for example, it has chartered planes to airlift vaccines and staff to the inaccessible southern part of the country.

The seven countries where polio still exists each must pass several tests before they can be declared free of the disease, including having no cases for three years. (In case you're wondering, the U.S. has been polio-free since 1993.) Rotarians would love to see some of the seven graduate by 2005, the organization's 100th birthday. Meanwhile, Renouf is now Sir Clem, knighted for his humanitarian work in connection with Rotary. --Carol J. Loomis