Three West African countries at the center of a polio epidemic launched an immunization drive on Sunday to help stop the spread of the crippling disease by the end of this year.

A boycott of the vaccine by Muslim leaders in northern Nigeria led to a doubling in the number of Nigerian children paralyzed by polio to 788 in 2004, and helped spread the virus to 12 African countries previously declared polio-free.

Muslim clerics backed by politicians rejected the polio vaccine in late 2003, saying they suspected it was contaminated with AIDS and infertility agents by Western powers seeking to depopulate the Muslim world.

Immunizations resumed eight months later after northern political leaders, under intense international and domestic pressure, agreed to re-examine the scientific evidence.

“If the global war against polio is to be won, the battle to end the transmission of polio must be fought and won in Nigeria in 2005,” said Nigerian Health Minister Eyitayo Lambo at the launch on the Nigeria-Benin border.

The presidents of Nigeria, Benin and Niger launched the new initiative, which will cover 23 African countries.

Nigeria, Africa’s most populous country which accounted for two-thirds of the world’s new polio cases last year, plans an intensive immunization campaign this year comprising five separate rounds aimed at 40 million children. “While there is one unimmunized child anywhere, there is a risk to children everywhere,” said Mohammed Belhocine, World Health Organization (WHO) representative in Nigeria.

The Nigerian boycott presented a major obstacle to a global attempt, spearheaded by the WHO and the United Nations children’s fund UNICEF, to wipe out polio forever by 2005.

International health experts say the goal of stopping transmission this year is still possible if the planned immunization rounds reach a high percentage of children.