Introduction and malaria vaccine development
Up-to-date information on malaria disease burden, status of malaria control and elimination, and evidence-based policy on malaria preventive, diagnostic and treatment measures is available on the WHO Global Malaria Programme web site.
Status of vaccine development
The complexity of the malaria parasite makes development of a malaria vaccine a very difficult task. Recent progress has been made with the completion of a Phase 3 trial of the RTS,S/AS01 candidate vaccine and review by the European Medicines Agency and WHO. There is currently no commercially available malaria vaccine. Over 20 other vaccine constructs are currently being evaluated in clinical trials or are in advanced preclinical development. See link to Rainbow table below.
The malaria vaccine candidate RTS,S/AS01
RTS,S/AS01 is the most advanced vaccine candidate against the most deadly form of human malaria, Plasmodium falciparum. A Phase 3 trial with 15 460 children in seven countries in sub-Saharan Africa (Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, and the United Republic of Tanzania) began in May 2009 and has now been completed.
There were two age categories in the trial:
- children aged 5-17 months at first dose receiving the RTS,S/AS01 vaccine or a comparator vaccine; and
- children aged 6-14 weeks at first dose who receive the RTS,S/AS01 vaccine or a comparator vaccine in co-administration with the pentavalent vaccine from the routine immunization schedule.
All children received 3 doses of study vaccines vaccine at 1 month intervals. The role of a fourth dose 20 months after the first dose was also evaluated.
After review of the study data, the European Medicines Agency issued a positive Scientific Opinion about the risk-benefit balance, upon agreement with the manufacturing company about further research plans as part of Phase 4 evaluation.
WHO, upon review of the data, recommended pilot implementation studies to be conducted for further evaluation of implementability of a four dose schedule in children aged 5-17 months at first dose and further evaluation of the risk/benefit profile.
A comprehensive WHO Q&A on RTS,S/A01 gives further information on policy and regulatory pathways. See link below.