RTS,S/AS01 (trade name Mosquirix) is a recombinant protein-based malaria vaccine. It is the only malaria vaccine approved and in wide use. , the vaccine has been given to 1million children living in areas with moderate-to-high malaria transmission, with millions more doses to be provided as the vaccine's production expands. It requires at least three doses in infants by age 2, with a fourth dose extending the protection for another 1-2 years. The vaccine reduces hospital admissions from severe malaria by around 30%. Medical uses RTS,S/AS01 (commercial name Mosquirix) is the only malaria vaccine approved and in current use. The vaccine's use requires at least three doses in infants by age 2, with a fourth dose extending the protection for another 1-2 years. The vaccine reduces hospital admissions from severe malaria by around 30%. History Potential malaria vaccines have been an intense area of research since the 1960s. SPf66 was tested extensively in endemic areas in the 1990s, but clinical trials showed it to be insufficiently effective. Other vaccine candidates, targeting the blood-stage of the malaria parasite's life cycle, had also been insufficient on their own. The RTS,S vaccine was conceived of and created in the late 1980s by scientists working at SmithKline Beecham Biologicals (now GlaxoSmithKline (GSK) Vaccines) laboratories in Belgium. The vaccine was further developed through a collaboration between GSK and the Walter Reed Army Institute of Research in the U.S. state of Maryland and has been funded in part by the non-profit PATH Malaria Vaccine Initiative (MVI) and the Bill and Melinda Gates Foundation. RTS,S was engineered using genes from the outer protein of P. falciparum malaria parasite and a portion of a hepatitis B virus plus a chemical adjuvant to boost the immune response. Infection is prevented by inducing high antibody titers that block the parasite from infecting the liver. In November 2012, a phase III trial of RTS,S found that it provided modest protection against both clinical and severe malaria in young infants. The RTS,S-based vaccine formulation had previously been demonstrated to be safe, well tolerated, immunogenic, and to potentially confer partial efficacy in both malaria-naive and malaria-experienced adults as well as children. In October 2013, preliminary results of a phase III clinical trial indicated that RTS,S/AS01 reduced the number of cases among young children by almost 50 percent and among infants by around 25 percent. The study ended in 2014. The effects of a booster