Malaria: The science of vaccines

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The World

Killing mosquitoes, or avoiding bites, is an imprecise solution to malaria. So for a more wide-ranging fix, epidemiologists are pinning their hopes on a malaria vaccine.

Promising results since human trials began in 2003 make it likely the RTS,S malaria vaccine will be the first to go into public use in the world’s malaria zones, perhaps as soon as 2012.

But RTS,S only works 50 to 60 percent of the time, and it’s engineered only for malaria’s most vulnerable victims, children from infancy to about age 5 (it works by pumping up a baby’s weak immune system long enough for the body to grow stronger). As a result, RTS,S is far from a “cure.”

Research on what comes next has already begun — even before RTS,S, hits the open market — and it includes work on an adult vaccine.

A first step for an adult vaccine came this spring, when a Rockville, Md., biotech company, Sanaria, began human trials on a vaccine. The Malaria Vaccine Initiative, a non-profit group also involved in the RRS,S project, has called the Sanaria project a promising vaccine candidate for adults. According to MVI, Sanaria’s idea is to create a weakened malaria parasite by irradiating infected mosquitoes. After nuking the bugs, Sanaria extracts the parasites and uses their weakened genetic material as the basis of a vaccine serum. The approach has been successful enough in lab tests to win FDA approval and move to the start of human trials.

Vaccine research has boomed since 1999, when the Bill and Melinda Gates Foundation, the Microsoft founder’s charity, made the disease a priority. MVI has received nearly a quarter billion dollars from the foundation in the past decade.

The boost in funding — and in incentives for scientists to work on the problem — has thrown a harsh light on decades of inattention by medical researchers, after malaria receded in Europe and the United States.

“Over a few years, the situation really deteriorated,” said Brian Greenwood, an elder statesman among malaria researchers, at a 2007 meeting of the world’s 300 or so top malaria experts in Seattle. “The deaths were going up, the treatment was failing and yet this was really not recognized until pretty late in almost an epidemic.”

The World Health Organization has estimated malaria infects as many as 300 million people each year.

Read more about malaria:

The situation in Colombia

The situation in India

The situation in Indonesia

The situation in Mozambique

The situation in South Africa

The science of prevention

One NGO worker’s quest

A vaccine in Ireland?

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