New malaria vaccine approach tested in mice

WASHINGTON, Dec 19 (Reuters) Scientists have tested in mice an experimental vaccine for malaria that does not provide immunity but aims to stamp it out in whole regions by eradicating the disease-causing parasite from mosquitoes that spread it.

In malaria, the single-celled parasite is injected into a person by the bite of a mosquito. Malaria kills a million people annually, mostly children under age 5 in Africa south of the Sahara.

The vaccine, developed by scientists at the US National Institutes of Health, is not designed to make the recipient less susceptible to malaria.

The hope instead is that when a mosquito bites a victim, because of changes in the person's immune system brought about by the vaccine, the parasite would be eliminated from the digestive tract of the blood-feasting mosquito, researchers said. The idea would be to make mosquitoes in a given area free of the parasite.

The experimental vaccine was developed with so-called conjugate technology, which joins molecules that the immune system has a hard time recognizing to molecules that the immune system can recognize more easily, the researchers said.

They described their work in the journal Proceedings of the National Academy of Sciences.

''The experimental malaria vaccine shows great promise for combating a terrible disease that exacts a devastating toll on the world's children,'' NIH Director Dr Elias Zerhouni said in a statement.

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