/ 24 October 2011

Vaccine could cut risk of malaria in children by 50%

Millions of children's lives could be saved by a new vaccine that has been shown to halve the risk of malaria in the first large-scale trials.

Millions of children’s lives could be saved by a new vaccine that has been shown to halve the risk of malaria in the first large-scale trials across seven African countries.

The long-awaited results of the largest malaria vaccine study, involving 15 460 babies and small children, show that it could massively reduce the impact of the much-feared killer disease. Malaria claims nearly 800 000 lives every year, most of them small children under the age of five. It damages many more.

The vaccine, which has been in development for two decades, is the brainchild of scientists at GlaxoSmithKline (GSK). The British drug company has promised to sell it at no more than a fraction over cost price, with the excess being ploughed back into further tropical disease research.

“This data brings us to the cusp of having the world’s first malaria vaccine, which has the potential to significantly improve the outlook for children living in malaria-endemic regions across Africa,” said GSK’s chief executive, Andrew Witty.

“The addition of a malaria vaccine to existing control interventions, such as bed nets and insecticide spraying, could potentially help prevent millions of cases of this debilitating disease. It could also reduce the burden on hospital services, freeing up beds to treat other patients who often live in remote villages, with little or no access to healthcare.”

Witty said that some of their peers thought the vaccine was an impossibility when the scientists started work on it 25 years ago.

“When the team was first shown the data, quite a number of them broke down in tears,” he said. “It was the emotion of what they had achieved — the first vaccine against a parasitic form of infection.”

The test results of the vaccine, still known only as “RTS,S”, were announced at a malaria forum in Seattle called by Bill and Melinda Gates, with World Health Organisation director general Margaret Chan present. They were published at the same time online by the New England Journal of Medicine.

Small-scale studies, in a few hundred children, have shown promising results in the past, but a trial of this size is needed to prove the vaccine’s usefulness across whole populations. It is being carried out in Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique and Tanzania.

This early data from five- to 17-month-old children is the first of three important results; the second outcome from the vaccination of newborn babies will be published next year. These are crucial, because the malaria vaccine needs to be incorporated into the infant immunisation schedule, alongside the usual diphtheria and measles jabs, but earlier small-scale trials suggest the results in six to 12-week-old babies will also show around 50% protection.

How long the vaccine lasts will not be known until 2014, with the protection rate appearing to drop from 47% to 35% for cases of severe malaria after 22 months. —