Malaria vaccine on the way to final-stage trials
[NAIROBI] Sixteen thousand children in seven African countries are due to undergo final-stage tests of a potential malaria vaccine early next year after research showed it halves the risk of malaria among infants and children in Kenya and Tanzania.
The next trials will expand to include Burkina Faso, Gabon, Ghana, Malawi and Mozambique. They are scheduled to begin by March 2009.
Results from the two East African clinical trials using the vaccine, currently known as RTS,S, were published last week (8 December) in The New England Journal of Medicine.
"The results advance the vision that a vaccine will be capable of protecting young African children and infants against malaria," says research clinician Ally Olotu, a co-author from the Kilifi-based Centre for Geographic Medicine Research, part of the Kenya Medical Research Institute.
One study showed that the vaccine — which stops the bloodborne parasite before it reaches the liver — could be included in the standard childhood immunisation schedule in African countries without interfering with the effectiveness of other vaccines or damaging its own effectiveness, Olutu says.
A second study confirmed the safety and effectiveness of the vaccine in babies and found that it reduced rates of malaria by half (53 per cent).
The next trials — on newborns 6–12 weeks old, and babies 5–17 months old — will provide even more information on the vaccine's effectiveness and safety, Olotu told SciDev.Net.
Salim Abdulla of the Ifakara Health Institute in Bagamoyo, Tanzania, says the latest Kenyan and Tanzanian trials confirm the results of earlier, smaller trials among adults in The Gambia and pre-schoolers in Mozambique, where the vaccine offered substantial protection against malaria for between 18 months and four years (see Mozambique starts malaria vaccine trial).
However, there are no plans to produce the vaccine in Africa and no information on its potential cost, Abdulla says. He told SciDev.Net that scientists are talking with nongovernmental organisations and health development bodies about a social marketing campaign for the rapid scale-up of the vaccine in the WHO and other immunisation programmes.
"These findings build a strong case for the phase III trials we have planned for 11 sites in Africa, says Abdulla, who participated in the trials at Tanzania's Tanga Medical Research Centre.
The New England Journal of Medicine 359, 2521 (2008)
The New England Journal of Medicine 359, 2533 (2008)