A vaccine to combat malaria could become a reality by 2014. While currently there are no licensed vaccines against malaria or any other human parasite, a research vaccine against P. falciparum, known as RTS,S/AS01, is at an advanced stage.
According to the WHO experts, the vaccine is currently being evaluated in a large clinical trial in 7 countries in Africa. However, the WHO recommendation for use will depend on the final results from the large clinical trial. “These final results are expected in late 2014, and a recommendation as to whether or not this vaccine should be added to existing malaria control tools is expected in 2015”.
The Phase 3 trial of RTS,S/AS01 that is under progress has been developed through a partnership between GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative (MVI), with funds from the Bill & Melinda Gates Foundation to MVI. The trials include 15,460 infants and young children in seven sub-Saharan African countries namely Burkina Faso, Gabon, Ghana, Ken-ya, Malawi, Mozambique, and Tanzania.
These countries represent a range of different malaria transmission settings in order to be able to determine the vaccine’s usefulness in these different settings. There are two age groups in the trial. One of these age groups is infants who receive three doses of the malaria vaccine together with other routine childhood vaccines at 6, 10 and 14 weeks of age. The other age group in the Phase 3 trial is older children aged between 5 and 17 months at first dose of RTS,S/AS01.
As of November 2012, two sets of results are available from the Phase 3 trial. The first results were released in October 2011 and were in children aged 5-17 months at first immunization. The estimated overall efficacy was a 55 per cent reduction in all malaria episodes during the 12 months of follow-up, with 47 per cent efficacy against severe, life-threatening malaria estimated in this same age group. Data for children vaccinated aged 6-14 weeks, in co-administration with other vaccines, were released in November 2012. Estimated overall efficacy in this age group over 12 months of follow-up was 33 per cent for all malaria episodes, and 37 per cent for severe, life-threatening malaria.