dose were positive, even though overall efficacy seems to wane with time. After four years, reductions were 36 percent for children who received three shots and a booster dose. Missing the booster dose reduced the efficacy against severe malaria to a negligible effect. The vaccine was shown to be less effective for infants. Three doses of vaccine plus a booster reduced the risk of clinical episodes by 26 percent over three years but offered no significant protection against severe malaria. In a bid to accommodate a larger group and guarantee a sustained availability for the general public, GSK applied for a marketing license with the European Medicines Agency (EMA) in July 2014. GSK treated the project as a non-profit initiative, with most funding coming from the Gates Foundation, a major contributor to malaria eradication. In July 2015, Mosquirix received a positive scientific opinion from the European Medicines Agency on the proposal for the vaccine to be used to vaccinate children aged 6 weeks to 17 months outside the European Union. It is the world's first licensed malaria vaccine and also the first vaccine licensed for use against a human parasitic disease of any kind. On 23 October 2015, WHO's Strategic Advisory Group of Experts on Immunization (SAGE) and the Malaria Policy Advisory Committee (MPAC) jointly recommended a pilot implementation of the vaccine in Africa. In November 2016, WHO announced that the RTS,S vaccine would be rolled out in pilot projects in three countries in sub-Saharan Africa. This pilot project for vaccination was launched on 23 April 2019 in Malawi, on 30 April 2019 in Ghana, and on 13 September 2019 in Kenya. In October 2021, the vaccine was endorsed by the World Health Organization (WHO) for "broad use" in children, making it the first malaria vaccine candidate, and first vaccine to address parasitic infection, to receive this recommendation. , 1million children in Ghana, Kenya and Malawi have received at least one shot of the vaccine. In August 2022, UNICEF awarded a contract to GSK to purchase 18million doses of the RTS,S vaccine over three years. More than 30 countries have areas with moderate to high malaria transmission where the vaccine is expected to be useful. Components and mechanism The RTS,S vaccine is based on a protein construct first developed by GlaxoSmithKline in 1986. It was named RTS because it was engineered using genes from the repeat ('R') and T-cell epitope