The World Health Organization says it is likely that Europe will be the next region to be declared free of the disease polio. According to WHO, there have been no indigenous cases of polio in Europe during the past three years.

The WHO says that with Europe's inclusion, more than half of the world will be certified as polio-free. The region represents 51 countries and more than 873 million people. Both of the Americas and the Western Pacific have already been designated polio-free.

The coordinator of the WHO global polio eradication project, Bruce Aylward, says it is easy to forget that polio was, until recently, a major problem in Europe. He says an initiative known as Operation Mecacar between 1995 and 1999 helped eradicate polio from the vast expanse of Europe. In the program, 18 countries coordinated massive immunization days twice yearly to reach 60 million children.

"This operation Mecacar was largely responsible for eradicating the disease from the European region," he says, "That model has been extremely important to the eradication program, and globally, because now other parts of the world - West Africa, Central Africa and other blocs - are synchronizing activities based on the leadership of the European region and the evidence it would work."

But Dr. Aylward says regions declared polio-free must remain vigilant against the disease being brought into the region by immigrants. "We do regularly see "importations" of virus into areas that have been polio-free," he says, "and these can be dealt with and stopped very, very quickly."

The WHO says it hopes to see polio eradicated worldwide by the year 2005. In order for this to happen, it says a massive effort will be needed to vaccinate people in India, Pakistan, Afghanistan, Nigeria, Niger, Somalia, Angola, and Egypt. The agency says about $275 million is still needed for the campaign.

The United Nations children's agency, UNICEF, and the service organization Rotary International have participated widely in the polio eradication campaign. Rotary estimates that about $1.5 billion could be saved each year if polio were eradicated everywhere in the world.