The Bill & Melinda Gates Foundation and Rotary International are joining forces with the British and German governments to immunize more children against polio. They have jointly pledged $US630 million.
An international effort has cut polio cases by 99% in 10 years - a drop from more than 350,000 cases in 1998 to about 1,600 in 2008.
Polio remains endemic in Afghanistan, India, Nigeria and Pakistan. Imported cases from these countries threaten other developing nations.
The Gates Foundation has pledged $US255 million and Rotary International $US100 million. Britain will provide about $US150 million and Germany about $US130 million.
The money will support a programme led by the World Health Organization and other agencies.
They hope to make polio the next disease to be eliminated worldwide, much as smallpox was declared eradicated three decades ago.
Polio is a virus that attacks the nervous system and can cause paralysis, difficulty breathing and sometimes death. It affects mainly children under the age of five.
Microsoft co-founder Bill Gates said on Wednesday there already has been a global investment of $US6 billion against polio.
However, he noted more children were infected with polio in 2008 than in 2007.
In addition, Nigeria imposed a yearlong vaccine ban in mid-2003.
Also, a suicide bomber in Afghanistan attacked a UN vehicle in September, killing two doctors working on polio vaccination for the WHO.
