A new vaccine indicated for the prevention of malaria in children has been recommended by the World Health Organization (WHO). The vaccine, R21/Matrix-M, is the second recommended by the organization, potentially alleviating some of the supply issues that have negatively impacted campaigns to control transmission of the virus.
This recommendation follows that of the RTS,S/AS01 vaccine, which was recommended in 2021. Both vaccines have been deemed safe and effective in preventing malaria in children, who are disproportionately affected, especially in regions such as Africa, where nearly 500,000 children die each year from the disease.
“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," said WHO Director-General Tedros Adhanom Ghebreyesus, in a statement.
Based on data from an ongoing clinical trial and other studies, the R21 vaccine has been shown to have a high degree of efficacy when administered just before the high transmission season, with data showing a 75% reduction in cases of malaria in the 12 months following the 3-dose series. A fourth booster dose administered 1 year later helped maintain efficacy.
Notably, the 2 malaria vaccines have not been studied in a head to head trial; however, the RTS,S vaccine has demonstrated similar efficacy and safety to the R21 vaccine when administered seasonally.
Key Updates
- WHO recommends new malaria vaccine, R21/Matrix-M for the prevention of malaria in children
- The new vaccine has comparable safety and efficacy compared with an existing recommended vaccine, RTS,S
- Live-attenuated quadrivalent dengue vaccine is recommended in children aged 6 to 16 years
- The pentavalent meningococcal conjugate vaccine targeting serogroups A, C, Y, W and X (Men5CV) should be incorporated into regular vaccine schedules for children aged 9 to 18 months
- Emphasizing a single-dose regimen for the COVID-19 vaccines may improve vaccine uptake and boost protection against circulating omicron variants.
Additional benefits beyond added supply include cost effectiveness, with the R21 vaccine priced at $2-4 per dose, which is on par with other malaria interventions.
According to WHO, 28 countries in Africa plan to roll out malaria vaccination programs, with at least 18 countries receiving technical and financial support to do so. Notably, the RTS,S vaccine will be rolled out in Africa in early 2024, followed by an expected rollout of the R21 vaccine in mid-2024.
Beyond malaria, WHO also made recommendations for new vaccines for the prevention of dengue, meningitis, and COVID-19.
For dengue, recommendations include rolling the live-attenuated quadrivalent dengue vaccine TAK-003 (Takeda) out in settings of high disease burden and high transmission, with vaccination being conducted in children age 6 to 16.
For meningitis, it is recommended that all countries in Africa with a high disease burden introduce the pentavalent meningococcal conjugate vaccine targeting serogroups A, C, Y, W and X (Men5CV) in persons aged 9 to 18 months, as well as a 'catch-up' campaign in those up to 19 years of age.
As for COVID-19, WHO's Strategic Advisory Group of Experts on Immunization (SAGE) recommended a simplified single-dose regimen for primary immunization in an effort to help improve uptake. Notably, SAGE noted that data support the monovalent omicron XBB vaccines as providing slightly enhanced protection over the bivalent variant-based vaccines and the monovalent index virus vaccines. The organization did note that if the monovalent XBB vaccines are not available, that any vaccine granted emergency use under WHO is acceptable to administer as they all provide some degree of benefit in high-risk groups.
REFERENCE
WHO recommends R21/Matrix-M vaccine for malaria prevention in updated advice on immunization. News release. October 2, 2023. Accessed October 6, 2023. https://www.who.int/news/item/02-10-2023-who-recommends-r21-matrix-m-vaccine-for-malaria-prevention-in-updated-advice-on-immunization
