The World Health Organization (WHO) has recommended a second vaccine, R21/Matrix-M, for the prevention of malaria in children.
The recommendation follows advice from the WHO Strategic Advisory Group of Experts on Immunization (SAGE) and the Malaria Policy Advisory Group (MPAG) and was endorsed by the WHO Director-General.
The R21 vaccine is the second malaria vaccine recommended by WHO, following the RTS, S/AS01 vaccine, which received a WHO recommendation in 2021.
Both vaccines are shown to be safe and effective in preventing malaria in children and, when implemented broadly, are expected to have a high public health impact.
Malaria remains one of Africa’s deadliest diseases, killing nearly half a million children under the age of 5, and accounting for approximately 95 percent of global malaria cases and 96 percent of deaths in 2021.
Nigeria carries the largest burden of the disease in the world, with more than 23 percent of deaths recorded according to the World Malaria Report 2020.
The addition of R21 to the list of WHO-recommended malaria vaccines is expected to result in sufficient vaccine supply to benefit all children living in areas where malaria is a public health risk.
“As a malaria researcher, I used to dream of the day we would have a safe and effective vaccine against malaria. Now we have two,” said Tedros Ghebreyesus, WHO director-general.
“Demand for the RTS,S vaccine far exceeds supply, so this second vaccine is a vital additional tool to protect more children faster, and to bring us closer to our vision of a malaria-free future.”
Matshidiso Moeti, WHO regional director for Africa, emphasized the importance of this recommendation for the continent, saying: “This second vaccine holds real potential to close the huge demand-and-supply gap. Delivered to scale and rolled out widely, the two vaccines can help bolster malaria prevention and control efforts and save hundreds of thousands of young lives in Africa from this deadly disease.”
According to WHO, the updated malaria vaccine recommendation is informed by evidence from an ongoing R21 vaccine clinical trial and other studies, which showed high efficacy when given just before the high transmission season
In areas with highly seasonal malaria transmission, the R21 vaccine was shown to reduce cases of malaria symptoms by 75 percent during the 12 months following a 3-dose series.
A fourth dose given a year after the third maintained efficacy. This high efficacy is similar to the efficacy demonstrated when RTS,S is given seasonally, WHO said.
The vaccine costs between $2 and $4 per dose, a rate considered cost-effective when compared with other recommended malaria interventions and other childhood vaccines.
The two WHO-recommended vaccines, R21 and RTS,S, have not been tested in a head-to-head trial. There is no evidence to date showing one vaccine performs better than the other.
The choice of product to be used in a country should be based on programmatic characteristics, vaccine supply, and vaccine affordability, WHO urged.
At least 28 countries in Africa plan to introduce a WHO-recommended malaria vaccine as part of their national immunization programmes.
Gavi, the Vaccine Alliance has approved providing technical and financial support to roll out malaria vaccines to 18 countries. The RTS,S vaccine will be rolled out in some African countries in early 2024, and the R21 malaria vaccine is expected to become available to countries in mid-2024.