The WHO approved the first Malaria vaccine in 2021. This vaccine RTS,S is currently being used in several countries in Africa, where it is expected to decrease the number if infant deaths from this deadly disease.
Malaria is caused by the Plasmodium parasite, of which there are four that infect humans: Falciparum, Vivax, Ovale, and Malariae. Of these, Falciparum is the most severe, with a 90% mortality rate without treatment, and a 20% mortality rate with adequate treatment. The Malaria parasite causes over 600,000 deaths every year, the majority of which are children under the age of 5. An effective vaccine is therefore highly desirable.
In October 2023, the WHO approved a second vaccine, R21/Matrix-M, that theoretically produces a stronger immune response and that costs about half the price of RTS,S. This will markedly increase the availability of the malaria vaccine for populations that need them most.
Both vaccines target a circumsporozoite protein found on the sporozoite form of the parasite that is injected into the bloodstream when the female Anopheles mosquito vector has a blood meal. Elimination at this stage prevents infection of red blood cells, prevents severe symptoms of the infection, and reduces death.
These vaccines are not perfect, however, and at least for RSTS,S, the immunity wanes after a few years leading to a rebound increased rate of malaria infection in older vaccinated children. But, by then, the likelihood of the child dying from malaria is significantly lower.
Malaria vaccination is still in its early stages, but we will most certainly see advancements in the near future producing more effective, safer and longer lasting vaccines. The question is: how soon?