RTS,S is the most clinically advanced malaria vaccine candidate in the world. Several clinical trials conducted in Africa in the last decade have shown it to be safe, well tolerated, and effective in the prevention of infection and clinical disease caused by Plasmodium falciparum, the most deadly species of malaria parasite.
The vaccine was initially developed and tested by GlaxoSmithKline (GSK) and the Walter Reed Army Institute of Research (USA) in the late eighties.
In 2003, the Manhiça Health Research Centre (CISM), in collaboration with the ISGlobal research centre CRESIB, started phase 2 trials that yielded the first conclusive evidence of its efficacy when vaccinated children were shown to have a significantly lower risk of becoming infected or developing clinical malaria than those in the control group.
A second study in 2007 showed that after a full vaccination course in infants, RTS,S reduced infection by 65% over a three-month follow-up period.
The final stage in the development of the RTS,S vaccine was launched simultaneously in 7 African countries with a multicentre phase 3 trial enrolling 16,000 African children.
Once all the data from this large-scale trial have been analyzed, a submission will be made to the regulatory authorities. At that time the WHO will also review the evidence before possibly recommending use of the vaccine on a large scale.
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