Mosquirix (RTS,S), recommended by WHO for widespread use, is the first vaccine that is around 30% effective against severe cases of the mosquito-borne disease malaria and is given to children aged 6 weeks to 17 months. GlaxoSmithKline's four-dose vaccine, which was under development for 30 years, acts against Plasmodium falciparum, the deadliest malaria parasite, which is most prevalent in Africa.