RTS,S/AS01 (trade name Mosquirix) is a protein-based recombinant malaria vaccine.
Approved for use by European regulators in July 2015, it is the world's first licensed malaria vaccine and also the first vaccine licensed for use against any human parasitic disease of any kind. The RTS,S vaccine was conceived and created in the late 1980s by scientists working at the SmithKline Beecham Biologicals (now GlaxoSmithKline Vaccines) laboratories in Belgium. The vaccine was developed through a collaboration between GSK and the Walter Reed Army Research Institute and was funded in part by the PATH Malaria Vaccine Initiative and the Bill & Melinda Gates Foundation. Its effectiveness ranges from 26 to 50% in babies and young children. On October 23, 2015, the World Health Organization's Strategic Advisory Group on Immunization (SAGE) and the Malaria Policy Advisory Committee (MPAC) jointly recommended a pilot implementation of the vaccine in Africa. was released on April 23, 2019 in Malawi, on April 30, 2019 in Ghana and on September 13, 2019 in Kenya.
Possible malaria vaccines have been an intensive area of research since the 1960s. SPf66 was tested extensively in endemic areas in the 1990s, but clinical trials have shown it to be insufficiently effective. Other vaccine candidates, targeting the blood stage of the malaria parasite's life cycle, were also insufficient on their own. Among several vaccines in potential development that target the pre-erythrocytic stage of the disease, RTS,S has shown the most promising results to date. RTS,S was most recently funded by the NGO PATH Malaria Vaccine Initiative (MVI ) and by GlaxoSmithKline, with funding from the Bill and Melinda Gates Foundation. The RTS,S vaccine formulation had already been shown to be safe, well-tolerated, immunogenic and potentially confer partial efficacy in malaria-experienced and unexperienced adults and children. 2012, the results of a phase III study of the RTS,S reported that they provided modest protection against clinical and severe malaria in young children. In October 2013, GlaxoSmithKline (GSK) reported that the RTS,S vaccine reduced the number of cases among young children by nearly 50% and by about 25% after the completion of an 18-month clinical trial. The data showed the protective effect after 18 months, however, it was less than previously observed after 12 months.
The EMA approved the RTS,S vaccine in July 2015, with a recommendation that it be used in Africa for babies at risk for malaria. RTS,S was the first malaria vaccine in the world to obtain approval for this use. After additional regulatory decisions by the World Health Organization and the governments of each African country, an "implementation" of the product could take place as early as 2017.
Preliminary research suggests that delayed fractional dosing can increase vaccine effectiveness by up to 86%. On 17 November 2016, WHO announced that the RTS,S vaccine would be launched in pilot projects in 3 countries in sub-Saharan Africa. The pilot program, coordinated by WHO, will assess the extent to which the protective effect of the vaccine shown in advanced clinical trials can be replicated in real-life environments. Specifically, the program will assess the feasibility of administering the required 4 doses of vaccine; the impact of the vaccine on saved lives; and vaccine safety in the context of routine use. The Ministry of Health Vaccines of Malawi, Ghana and Kenya started in April and September 2019 and target 360,000 children a year in areas where vaccination would have the greatest impact. The results are planned to be used by the World Health Organization for