Microsoft founder Bill Gates and the government of Norway have pledged more than $1 billion for a campaign to vaccinate most of the world's poorest children.
Donors say they hope the $750 million grant from the Bill and Melinda Gates Foundation and a pledge from Norway for $290 million spurs other foundations and governments to invest in The Global Alliance for Vaccines and Immunization.
The alliance hopes to immunize 90 percent of the world's children by 2015. The group estimates it will cost $8 to $12 billion.
The World Health Organization estimates two million people die each year from diseases that are easily prevented by basic vaccines.
Some information for this report provided by AP and Reuters.