A candidate vaccine against malaria has recently undergone two promising clinical studies. The first produced a 65% drop in the number of infections and a 59% reduction in malaria attacks following infection. The second, which focused on a particular adjuvant, also reduced the number of episodes of malaria.
Developed by the GlaxoSmithKline (GSK) laboratory, this vaccine was evaluated in the field in Tanzania and Kenya. The first study involved 340 Tanzanian infants under the age of one, who were monitored for 6 months. In addition to the positive results already mentioned, it was also shown that the new candidate vaccine does not compromise the effectiveness of other childhood vaccines. This benefit appears to be certain, providing that all the vaccines are administered at the same time.
The second study – involving 894 Kenyan and Tanzanian infants under the age of 17 months – was aimed at evaluating the effectiveness and safety of the vaccine in association with the new adjuvant ASO1. The verdict? Malaria episodes dropped by 53% over an 8-month period. A better result than was noted in a study conducted in Mozambique with another adjuvant (ASO2) which only produced a 35% decrease over 18 months.
The director of the Malaria Vaccine Initiative, Christian Loucq, cannot conceal his excitement. “Creating a vaccine against malaria has never been so close”, he points out. For the MVI, an organisation funded by the Bill and Melinda Gates Foundation, the next stage will be a phase III study conducted in 7 African countries. And it will start as early as 2009. This trial should be the last required before applying for approval to market the vaccine.