The World Health Organization (WHO) has recommended a new vaccine, R21/Matrix-M, to prevent 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 following its regular biannual meeting held recently.
The R21 vaccine is the second malaria vaccine recommended by the 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.
Although demand for malaria vaccines is unprecedented, RTS,S vaccine availability is limited. 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 Adhanom Ghebreyesus, PhD, the 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.”
Key features of the R21 malaria vaccine
The updated WHO 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 (where malaria transmission is largely limited to four or five months per year), the R21 vaccine was shown to reduce symptomatic cases of malaria by 75 percent during the 12 months following a three-dose series.
Good efficacy when given in an age-based schedule: The vaccine showed good efficacy (66 percent) during the 12 months following the first three doses. A fourth dose a year after the third maintained efficacy.
High impact: Mathematical modeling estimates indicate the public health impact of the R21 vaccine to be high in a wide range of malaria transmission settings, including low transmission settings.
Cost-effectiveness: At prices of $2–$4 per dose, the cost-effectiveness of the R21 vaccine would be comparable with other recommended malaria interventions and other childhood vaccines.
Similarity with RTS,S 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.
Safety: The R21 vaccine was shown to be safe in clinical trials. As with other new vaccines, safety monitoring will continue.
The next steps for the second recommended malaria vaccine, R21/Matrix-M, include completing the ongoing WHO prequalification which would enable international procurement of the vaccine for a broader rollout.
- This press release was originally published on the World Health Organization website