“When a mosquito infected with malaria bites a person, it injects a few dozen sporozoites into the bloodstream. These long, sprightly forms of the parasitic protozoan reach the liver within an hour; there the parasite transforms and multiplies, causing infection and sometimes death. Stop the parasite early, when the sporozoites are few in number, and disease is averted.

That is the premise of both new vaccines, which create antibodies that attach to sporozoites of the parasite Plasmodium falciparum, responsible for almost all of the deaths globally. The first to arrive was RTS,S which was developed in 1987 by GSK, a British company, and recommended by the WHO in 2021. Combining it with antimalarial drugs in places with high seasonal transmission of the disease reduced malaria episodes and deaths in young children by nearly two-thirds, compared with jabs or antimalarial drugs alone. Adding bed nets probably raised protection to more than 90%.”

From The Economist.