25.07.2011
Breakthrough: A new malaria vaccine found to be safe, well tolerated and efficacious to reduce malaria in Tanzanian children
The Swiss Tropical and Public Health Institute, one of the important players in the malaria vaccine development field, announced today a major breakthrough in the fight against malaria, one of the major serial killer of children in Africa. They report that a new malaria vaccine conferred 50% protection to Tanzanian children against clinical episodes of malaria.
The tested vaccine is made of two synthetic peptide components (AMA-1 and CSP-1) that mimic the native structure of crucial antigens found during the key stages of the malaria parasite (Plasmodium falciparum) life cycle. It is formulated with influenza-based virosomes as antigen carrier and adjuvant, a technology platform already approved for vaccines against hepatitis A and influenza in more than 40 countries.
The Phase Ib trial was conducted at the Bagamoyo Research & Training Centre in Tanzania under the leadership of Profs. Blaise Genton & Marcel Tanner (Swiss TPH, University of Basel) and Dr Salim Abdulla, director of the Ifakara Health Institute (IHI). The vaccine, developed by Prof. Gerd Pluschke (Swiss TPH) and Prof. John Robinson (University of Zürich) in collaboration with Pevion Biotech AG, was tested during a 12-month period in 50 healthy, semi-immune volunteers (40 children, 10 adults) under malaria endemic conditions. Each subject received two injections that were well tolerated by both adults and children as young as 5 years of age, without any safety issues. The vaccine induced high antibody responses against the two antigens (AMA-1 and CSP-1) in most of the subjects. More importantly, the vaccine was efficacious to reduce the number of clinical episodes of malaria in children. Indeed, the incidence of malaria attacks was half in those who received the malaria vaccine compared to those that were injected the comparator vaccine (influenza vaccine).
These results are very promising. Indeed, this is the only malaria vaccine that has demonstrated efficacy to protect populations living in endemic areas, apart RTS’S, a product that is in Phase III trial in several sites in Africa. 50% protection against malaria episodes means that the overall burden could be cut by half, should these results be confirmed in a larger sample of subjects. Also, it gives hope that the efficacy of a first generation malaria vaccine can be rapidly improved by combining different antigens or different technology platforms. Following this successful Phase Ib trial, the different collaborators involved, as well as Mymetics Corporation (who acquired the Malaria program from Pevion Biotech AG in 2007 and contributed to the funding of the Phase 1b study) are now preparing the next phase of development of the multi-stage vaccine with additional promising malarial antigens that can be added to the present formulation.
These exciting results allow optimism for the successful development of a malaria vaccine in the near future. This will represent an additional tool to fight malaria and play a key role in integrated control and elimination programs.
Link to the article: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0022273