How do vaccines protect against malaria?

Malaria is caused by Plasmodium parasites, not viruses or bacteria, which makes vaccine design difficult. The first malaria vaccines to receive broad use, RTS,S and R21, target the Plasmodium falciparum parasite during an early stage of infection. They do not provide complete protection, but they can reduce severe disease and deaths when used alongside bed nets and antimalarial drugs. The RTS,S vaccine was recommended by the World Health Organization in 2021. Malaria remains a major global health problem, especially in sub-Saharan Africa.