Since 1995, the Bill & Melinda Gates Foundation has pledged $5.6 billion for global health, mostly to develop and distribute vaccines in developing countries.

That sustained generosity spurred greater attention and investment toward diseases of the developing world, including AIDS, malaria and tuberculosis. Now the foundation prods science by doubling to $450 million a pledge for research into new vaccines, drugs and health tools. The money will be awarded to researchers tackling 14 specific public-health issues.

The announcement is exhilarating for scientists and potentially life-saving in parts of the world where basic medical treatment isn't available.

In a speech before members of the World Health Organization, foundation co-founder Bill Gates said the private sector is not creating vaccines and medicines for infectious diseases because developing countries can't buy them. To counter that, Gates uses a strategy that worked building Microsoft: challenge grants that foster competition and get science and technology doing what the private sector won't.

This tactic is not without its critics. An article in the British medical journal The Lancet takes Gates to task for not including economic, social and political strategies in his approach to disease eradication.

The battle plan for saving lives is a worthwhile debate. However, it shouldn't overshadow the tremendous potential of the Gates challenge grants. Science has made enormous strides over the past five years, most notably sequencing the human genome and identifying the pathogens that cause infectious disease. But this kind of work is painstakingly slow. Advances are made in baby steps.

The Gates' investment speeds up the interaction between science and applying its results. By challenging science and technology worldwide, Gates predicts more advances for public health in the next 10 years than were seen in the past 50 years.

That's wonderful from a scientific perspective. It is especially so from the perspective of those living in poor countries.