Philanthropists do not typically lavish their money on swine. Or mosquitoes, for that matter.
But Microsoft Chairman Bill Gates is no ordinary philanthropist. If immunizing pigs can end the spread of tapeworms, which cause virulent neurological disorders, he will pay to vaccinate them. If mosquitoes can be neutralized as malaria carriers by altering their genetic code, his money - and lots of it - will support the research.
"The basic science that can be applied to these problems has been advanced greatly," Gates said in a recent interview at the company's headquarters in Redmond, Wash. "So all you have to do is take a modest amount of the rich world's resources to have a huge impact on the poor world."
"Modest" is a relative term, particularly when the person using it is the world's richest man and is speaking of his plans to solve intractable health problems on a global scale.
The Bill & Melinda Gates Foundation, which has distributed $6.2 billion since its founding less than four years ago, has pledged more than half of that, or $3.2 billion, to improving health in the developing world.
The foundation's influence rivals that of the World Health Organization and UNICEF.
Here is one point of comparison: The Global Fund to Fight AIDS, Tuberculosis and Malaria - a partnership of 14 countries with private charities, foundations and industry - plans to spend roughly $1.5 billion to fight those diseases during the next two to three years. About $50 million of that comes from the Gates Foundation.
The Gates Foundation has spent more than $610 million on those diseases and will spend at least another $478 million by the end of 2005.
The foundation's influence can be seen in rising vaccination rates in some of the world's poorest countries, in clinical trials of drugs that are promising but have limited commercial potential and in new devices that make the delivery of health care easier and cheaper.
Dr. Tore Godal, executive secretary of Global Alliance for Vaccines and Immunization, a major Gates beneficiary, said it had delivered more than 180 million doses of vaccines since 2000, thus saving more than 100,000 lives. Gates figures that his philanthropy will have touched more than a million lives by the end of the decade, and his goal is to reach tens of millions more.
"Bill Gates is going to be remembered more for what he did for international public health than what he did for the world of computers," said Richard T. Mahoney, a professor at Arizona State University who has wide experience dealing with health issues in poor countries.
Those who think of Gates as a ruthless billionaire monopolist, the man who was so testy and sarcastic with government prosecutors during the Microsoft antitrust trial, might find it hard to reconcile that image with one of a humorously self-deprecating philanthropist.
Many suspected that Gates' plunge into works of charity, which took off at the time of the trial, was aimed at polishing his image. Others have criticized it as an effort to build markets for Microsoft, turning sick people into healthy customers.
But if his foundation is a public relations exercise, it is one that experts in the field agree is innovative, ambitious and bold.
"It seems to me - and I've been following his work - that this is a guy with a vision," said Michael Bailin, president of the Edna Clark McConnell Foundation. "He's willing to put his money out there and make some big but good gambles on some of the most important issues there are."
Where the fledgling Gates Foundation once sought guidance from philanthropic blue- bloods such as Rockefeller and Carnegie, budding philanthropists now turn to Gates for advice. In April, Michael S. Dell, the computer billionaire who is quietly increasing his philanthropy, sent Janet Mountain, the new executive director of his foundation, to Seattle to see how the Gates Foundation does things.
What she saw was a foundation that spreads its wealth generously but cautiously, hedging its bets by financing collaborative efforts that involve governments, private industry, scientists, nonprofit organizations and organizations such as UNICEF.
About 80 percent of the foundation's contributions to global health are funneled through public-private partnerships that bring together all the parties needed to sustain successful programs.
In part, that approach is a necessity: The foundation needs a big conduit to accommodate its big grants.
But it is also smart philanthropy, experts say. "They don't focus on defining a problem and looking to single-handedly address it, although they certainly could," said Melissa A. Berman, president and chief executive of Rockefeller Philanthropy Advisers. "They look at a whole system and how that system can be used to address the problem on a very large scale. They are always looking at the grander vision."