Antimalaria vaccine candidate rolls towards success
A trial of an antimalaria vaccine in Mozambique has found that it can be safely used in infants and shows promise in protecting them against infection.
The results were published online in The Lancet this week (17 October).
Researchers from the Manhica Health Research Centre, Mozambique, and colleagues inoculated 214 babies with the GlaxoSmithKline 'RTS,S/AS02D' candidate vaccine, along with routine childhood vaccines.
The vaccine, which stimulates the production of antibodies against the malaria parasite Plasmodium falciparum, has already been tested in children aged 1–4 years (see 'Mozambique starts malaria vaccine trial') and was shown to reduce the risk of infection and disease.
This latest trial involved babies aged between 10–18 weeks born in an area of Mozambique with endemic malaria.
Because children under two years old living in such areas have a disproportionately high incidence of disease and death from malaria, they need protection as soon as possible after birth.
The trial was designed to test the safety of the candidate vaccine, and showed that the babies tolerated the three doses with no serious side-effects over six months of follow-up monitoring.
The researchers found that the vaccine stimulated the production of antibodies and was 65 per cent effective against new infection after three months of follow-up.
The candidate vaccine also reduced episodes of clinical malaria by 35 per cent over six months of follow-up — although the authors emphasise that further trials are needed to test its efficacy against disease rigorously.
Christian Loucq, director of the PATH Malaria Vaccine Initiative, which helped fund the trial, says, "The significance [of the results] is quite important for African children because it gives a very positive indicator that the vaccine works in infants."
He said the fact that it can be given at the same time as other childhood immunisations is extremely positive.
"Childhood vaccination programmes are in place and reach the largest number of babies in Africa. If we can add this vaccine to the programme, we have a much better chance of high coverage," he said.
He said the vaccine could be important in controlling malaria, in conjunction with mosquito bednets and pesticide sprays.
Vaccine testing is supported by funding from the Bill and Melinda Gates Foundation through PATH.
The researchers hope to begin the next (phase III) trial to test for efficacy against disease by the second half of 2008.
Reference: The Lancet doi 10.1016/S0140-6736(07)61542-6 (2007)