The Economist: Malaria: Exterminate! Exterminate!
New malaria vaccines—and a pep talk from the man who is paying for some of them—are raising the idea that malaria might be eliminated once and for all.
“WE'VE made vaccines from pus and poop, we make them now using eggs—so why not make them in live mosquitoes?” So says Stefan Kappe, a researcher at the Seattle Biomedical Research Institute. To prove the point, his team is breeding millions of Anopheles mosquitoes (pictured above) and infecting them with malaria-causing parasites.
Not any old parasites, either. Those he uses have had some of their genes knocked out to stop them breeding in humans. Their destiny, like that of the “attenuated” viral strains grown in eggs, is to form part of a vaccine.
Once the parasites have had time to breed in the mosquitoes, the insects are killed and dissected under a microscope. The gold inside them is their salivary glands, the parts richest in parasites. These are extracted, processed and turned into what Dr Kappe hopes will become a successful vaccine. By injecting this vaccine of pared-down parasites into uninfected individuals, he intends to provoke an immune response to malaria that will be strong enough to kill a real infection before it gets going.
Provoking such a response is, of course, the idea behind any vaccine, and there are various ways of doing it. Dr Kappe's looks promising in the laboratory, but has yet to undergo clinical trials. Another method, however, has been on trial for several years by Pedro Alonso of the Barcelona Centre for International Health Research. This week saw the publication in the Lancet of the latest results from those trials. They look very promising indeed. …
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