Stung to death: think tsunamis and terrorism are the world's big problems? Bill Gates knows better.

Malaria is no longer a threat to industrialized nations. Yet worldwide each year the disease kills as many as 3 million people, most of them children. A mosquito-borne disease, it causes high fevers, chills, night sweats, headaches, abdominal pain and severe respiratory problems.

Malaria mostly kills Africans. Yet in Latin America 40 million people live in areas of risk and 1 million cases have been reported annually since 1997, according to the Pan American Health Organization. Malaria is endemic in 21 Latin America countries and has steadily increased in six nations since 2000--Colombia, the Dominican Republic, Guyana, Panama, Peru and Venezuela--according to the agency.

In past decades, most large pharmaceutical companies ignored this catastrophe. Big Pharma CEOs were reluctant to justify the high cost of research for drugs that few patients and healthcare systems could pay for. Just 10% of total health-research resources are invested in illnesses that account for 90% of global disease. According to Doctors Without Borders, just 13 out of 1,233 new medicines marketed by major drug companies between 1975 and 1997 were designed to treat tropical parasitic illnesses such as malaria, Chagas disease--the leading cause of heart disease in Latin America, one which claims 50,000 people each year--and leishmaniasis, a fatal disease transmitted by sandflies.

But now there is hope of the first-ever malaria vaccine, thanks mainly to the world's richest man, Microsoft's Bill Gates, who says malaria is "easily the worst thing on the planet" in terms of human suffering. In October, the Bill and Melinda Gates Foundation announced its latest donation to combat malaria--US$258 million--of which $108 million will go to search for a vaccine, $100 million to hunt for new drugs (resistance to older drugs is becoming common), and $50 million to develop insecticides and other forms of mosquito control.

Since its inception four years ago, the Gates Foundation has invested more than $1.60 billion to develop new drugs for ailments that affect the world's poor, with about $300 million destined for malaria research. The foundation is the world's largest charitable organization, wielding a $29 billion endowment, a figure which dwarfs the $1.60 billion annual budget of the World Health Organization.

I applaud Gates for turning attention to diseases that attract little research money, which remain major health problems in the developing world. Health experts estimate that Gates funds more than a third of the world's research budget for malaria alone; there are now six new drugs in clinical trials compared with none five years ago. His foundation also teamed up with drug giant GlaxoSmithKline in hopes of creating a cheap malaria vaccine by 2011.

To its credit, the United States remains the biggest donor nation in fighting malaria. Between 1998 and 2005, Washington increased its annual commitment to $89 million from $22 million. In June, President George W. Bush pledged another $1.20 billion over five years to expand malaria prevention and treatment programs in Africa. But the Gates Foundation outspends the seven most powerful economies in the world combined in research of vaccines for poor people's diseases, according to Harvard University.

There are other heroes waging war on these lethal parasitic diseases.

In the forefront is San Francisco pharmacologist Victoria Hale, founder of the first non-profit U.S. pharmaceutical company. With grants from the Gates Foundation, her Institute for OneWorld Health is developing drugs to treat leishmaniasis and Chagas. Her novel drug company is also working to develop a cheaper version of an ancient Chinese remedy that is considered the most effective cure for malaria: If successful, the company will produce a synthetic form of artemisinin, a herbal medicine derived from wormwood plants at under $1 per dose.

In the meantime, Latin American governments should do their part by providing insecticide-treated bed nets to those who cannot afford them (they cost $5). Governments need also to halt global warming and deforestation. Experts say global warming has caused malaria to spread to traditionally cool mountain areas. A study by Johns Hopkins found that even a 1% rise in deforestation increased the number of malaria-bearing mosquitoes in Peru by 8%.

Gates and Hale are fighting the good fight in a valiant attempt to weaken malaria's grip on the developing world. Finding a vaccine would send a potent message that drug companies can improve the lives of hundreds of millions of poor--a public they have traditionally ignored.