The World Health Organization (WHO) has given its approval for the use of the R21/Matrix-M malaria vaccine, which was jointly developed by the University of Oxford and the Serum Institute of India. This endorsement comes after the vaccine successfully met all the necessary safety, quality, and effectiveness criteria.
WHO has also issued recommendations for new vaccines targeting dengue and meningitis, as well as provided guidance on immunization schedules and product recommendations for COVID-19. Furthermore, the WHO has released significant programmatic recommendations regarding polio, IA2030, and the recovery of immunization programs.
The World Health Organization (WHO) has recommended the R21 vaccine as the second malaria vaccine, alongside the RTS,S/AS01 vaccine endorsed in 2021. Both vaccines have proven safe and effective in preventing malaria in children, with potential to significantly improve public health, particularly in Africa where many children die from the disease. A high demand for malaria vaccines exists, but the limited supply of RTS,S is a concern. The addition of R21 to WHO's recommended vaccines is expected to alleviate this shortage and benefit children in malaria-endemic areas.
What is Matrix-M or R 21?
The R21/Matrix-M vaccine is designed to combat the initial stage of the malaria parasite's entry into the human body, focusing on the plasmodium 'sporozoite.' Infected mosquitoes introduce a relatively small number (10–100) of sporozoites into the body before the parasite starts to replicate, making these sporozoites the perfect candidate for vaccination.
Here's What WHO Official Says
Dr. Tedros Adhanom Ghebreyesus, the WHO Director-General, expressed his enthusiasm, saying, "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. The demand for the RTS,S vaccine exceeds its supply, so this second vaccine is a crucial additional tool to protect more children quickly and bring us closer to our goal of a malaria-free future."
Dr. Matshidiso Moeti, the WHO Regional Director for Africa, emphasized the significance of this recommendation for the continent, stating, "This second vaccine has the potential to bridge the significant gap between demand and supply. When delivered at scale and widely distributed, these two vaccines can reinforce malaria prevention and control efforts, ultimately saving hundreds of thousands of young lives in Africa from this deadly disease."
R21 Malaria Vaccine Key Features
The updated recommendation from the World Health Organization (WHO) regarding the malaria vaccine is based on evidence from an ongoing clinical trial of the R21 vaccine and other research. The findings include:
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High effectiveness when administered just before the peak malaria transmission season: In regions with highly seasonal malaria transmission, where the disease is prevalent for only 4 or 5 months per year, the R21 vaccine reduced symptomatic malaria cases by 75% in the 12 months following a three-dose series. Adding a fourth dose a year later maintained this high effectiveness, similar to the seasonal effectiveness of RTS,S.
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Good effectiveness in an age-based schedule: The vaccine displayed good effectiveness (66%) in the year following the initial three doses. A fourth dose given a year later maintained this effectiveness.
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Significant public health impact: Mathematical models suggest that the R21 vaccine is expected to have a substantial positive impact on public health in various malaria transmission settings, including areas with low transmission rates.
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Cost-effectiveness: At prices ranging from US$2 to US$4 per dose, the cost-effectiveness of the R21 vaccine is comparable to other recommended malaria interventions and childhood vaccines.
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Similarity between R21 and RTS,S vaccines: Both WHO-recommended vaccines, R21 and RTS,S, have not been directly compared in a head-to-head trial, and there is no evidence indicating one vaccine is superior to the other. The choice of which vaccine to use in a country should be based on programmatic considerations, vaccine availability, and affordability.
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Safety: The R21 vaccine has demonstrated safety in clinical trials, and ongoing safety monitoring will continue, as is standard practice for new vaccines.
The next steps for the second recommended malaria vaccine, R21/Matrix-M, include completing the ongoing WHO prequalification process, which would enable international procurement of the vaccine for wider distribution.
A total of at least 28 African countries plan to introduce a WHO-recommended malaria vaccine as part of their national immunization programs. The Gavi Vaccine Alliance has approved providing technical and financial support for the rollout of malaria vaccines in 18 countries. The RTS,S vaccine is expected to be introduced in some African countries in early 2024, while the R21 malaria vaccine is anticipated to become available to countries in mid-2024.
