We must now close in on the remaining strongholds of the disease and use all possible resources to extinguish polio

Dr Gro Harlem Brundtland, WHO

While even a few tiny reservoirs of the disease remain, they say, the disease could re-emerge and strike at future generations.

Dr Gro Harlem Brundtland, director general of the World Health Organisation, said: "Victory over the poliovirus is within sight."

"We must now close in on the remaining strongholds of the disease and use all possible resources to extinguish polio.

"We ask that everyone involved maintain the focus on achieving this historical milestone in international public health."

Last year, 550m children under five-years-old were immunised during "national immunisation days" in 82 countries.

The organisations behind the campaign, which, alongside the WHO, include Rotary International, the US Centres for Disease Control and Prevention, and the United Nations Children's Fund (Unicef), say that they are still on course for a world free of polio by 2005.

War and polio

Carol Bellamy, executive director of Unicef, said that the initiative now needs to reach children in even the most remote places on Earth.

Which countries still have polio?

Afghanistan Angola Bangladesh Benin Central African Republic Chad Congo Cote D'Ivoire DR Congo Egypt Ethiopia Ghana India Nepal Niger Nigeria Pakistan Sierra Leone Somalia Sudan

She said: "It's essential that warring parties and international mediators give priority to ceasefires that allow us to get polio vaccine to these children."

More money is also needed - an estimated �285m to provide an estimated 6bn doses of vaccine to 600m children by 2005.

Polio is a highly infectious disease - the virus that causes it invades the nervous system and can cause paralysis.

One in 200 infections leads to irreversible paralysis and between 5% and 10% of those infected die.

Until worldwide coverage with vaccination can be achieved, whole communities are at risk from outbreaks.

An outbreak in August last year on the west African island of Cape Verde killed 17 and paralysed 44.

All pictures courtesy of Marcel Crozet/WHO.