Malaria vaccine: immunity in Tanzanian children raise hopes

May 23, 2014

US scientists find 'compelling evidence' that antibodies can combat the 'formidable' disease

TIM SLOAN/AFP/Getty Images

Scientists are working on a new vaccine for malaria – with help from a group of Tanzanian children who are naturally immune to the disease.

US researchers took regular blood samples from 1,000 children in the first years of their lives and found that around six in every 100 developed immunity to malaria.

The antibody produced by those children, which attacks the malaria-causing parasite, has been found to protect mice from the disease when injected into the animals.

The results, which have been published in Science magazine, suggest this antibody could act as a potential vaccine. However, scientists want to carry out trials on monkeys and humans first.

"The animal that kills the most humans worldwide isn't the shark, lion, or grizzly bear: it's the mosquito," says Science. The World Health Organisation suggests the disease killed more than 600,000 people in 2012, with 90 per cent of these deaths occurring in sub-Saharan Africa and most of them children under five.

Despite the best efforts of researchers, no vaccine has yet been developed. But the antibody found in the immune children hits the malaria parasite at a key stage in its life-cycle, say the researchers, trapping the tiny organism in red blood cells to prevent it from bursting out and spreading through the body.

The mice injected with the antibody survived twice as long as those who were not vaccinated and, in one trial, had only one quarter of the parasites found in untreated mice.

Prof Jake Kurtis, director of the Centre for International Health Research at Rhode Island Hospital, Brown University, said: "I think there's fairly compelling evidence that this is a bona fide vaccine candidate.

"However it's an incredibly difficult parasite to attack. It's had millions of years of evolution to co-opt and adapt to our immune responses – it really is a formidable enemy."

Prof Kurtis added that he was "cautious" but said he had seen "nothing so far in our data that would cause us to lose enthusiasm".

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