Malaria
The complexity of the malaria parasite makes development of a malaria vaccine a very difficult task. Given this, there is currently no commercially available malaria vaccine, despite many decades of intense research and development effort. The most advanced vaccine candidate against the most deadly form of human malaria, Plasmodium falciparum, is RTS,S/AS01. This vaccine has shown 51% efficacy in reducing all episodes of clinical malaria in infants aged 5-17 months over 15 months in a phase 2 trial in Kenya. There are few published data on clinical efficacy when administered to the target population i.e. infants at 6-14 weeks of age, together with vaccines in the routine immunization schedule. A phase 3 trial began in May 2009 and has completed enrollment with 15 460 children in the following seven countries in sub-Saharan Africa: Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, and the United Republic of Tanzania. There are two groups in the trial: 1) children aged 5-17 months at first dose receiving only the RTS,S/AS01 vaccine; and 2) children aged 6-12 weeks at first dose who receive the same malaria vaccine in co-administration with pentavalent vaccines in the routine immunization schedule. Both groups receive 3 doses of RTS,S/AS01 vaccine at 1 month intervals.
According to the current trial schedule, the phase 3 trial data required in order for WHO to consider making a policy recommendation is expected to become available to WHO in early 2015.
The first of the interim reports of the phase 3 trial became available in October 2011. The efficacy figure was 55% reduction in frequency of malaria episodes during the 12 months of follow-up in children 5-17 months of age at first immunization. This is not the vaccine development partnership's stated target population, which is children aged 6-14 weeks of age, in co-administration with other vaccines. The efficacy in this target population is not yet known.
A further interim report is expected in late 2012.
Further information on malaria vaccine research
- Most advanced vaccine candidate and timing for policy recommendations
-
Questions and answers on malaria vaccines
pdf, 49kb - Status of malaria vaccine research projects
- Malaria vaccinology
- WHO technical expert group on malaria vaccines
- MALVAC 2010: measures of efficacy for transmission-reducing interventions
- Vaccine research meetings including access to presentations
- Malaria Vaccine Funders Group
- Global Malaria Programme
- Additional WHO material on malaria
Last updated: 19 October 2011