Four years after the world's first large-scale malaria vaccination campaign, the results are decisive: In Ghana, Kenya, and Malawi, RTS,S prevented one in every eight deaths among vaccinated children. Overall child mortality in this group fell 13 percent. A study published in The Lancet provides the first real-world proof that malaria vaccination protects children in Africa under everyday conditions, not just in clinical trials.
Malaria kills 438,000 African children annually
Malaria kills. According to the WHO, roughly 438,000 children under five in sub-Saharan Africa died from the disease in 2024, transmitted by Anopheles mosquitoes. Globally, the WHO counts over 600,000 malaria deaths per year, predominantly young children. Malaria remains one of the single largest causes of child mortality worldwide.
GlaxoSmithKline and the PATH Malaria Vaccine Initiative developed the first malaria vaccine over more than three decades, with funding from the Gates Foundation. In 2021, the WHO recommended RTS,S for broad use across Africa. This followed the Malaria Vaccine Implementation Programme (MVIP), which began in 2019 in Ghana, Kenya, and Malawi. By 2023, over one million children had been vaccinated. Critically, this was not a laboratory setting. The program tested under real conditions in local health systems with limited resources and varying vaccination rates.
13 percent mortality reduction despite incomplete vaccination coverage
The Lancet analysis examined data from 2019 to 2023. The core finding: in regions with RTS,S programs, overall mortality among eligible children fell 13 percent. One in eight deaths was prevented. Severe malaria cases declined by 22 percent.
Remarkably, these results were achieved despite incomplete vaccination coverage. The WHO reported that 71 percent of children received all three primary doses. Fewer than half received the fourth booster dose. Yet a clear protective effect was evident. Dr. Kate O'Brien, WHO director of immunization, called it a historic result: proof the vaccine works under real-world conditions.
Researchers from the London School of Hygiene and Tropical Medicine emphasized the finding exceeded expectations from earlier randomized trials. A likely explanation is herd immunity: when a significant portion of children are vaccinated, malaria transmission in the entire community drops, protecting unvaccinated children too.
What earlier vaccine successes demonstrated
RTS,S fits into a history of transformative vaccine breakthroughs. In 1988, the WHO recorded roughly 350,000 polio cases annually worldwide. In 2024, only Pakistan and Afghanistan remain endemic. Near-complete polio eradication is the result of consistent vaccination campaigns over decades in regions with sometimes weak health infrastructure.
Hepatitis B shows a similar pattern. The WHO puts vaccine efficacy at 95 percent. Taiwan introduced universal infant hepatitis B vaccination in 1984, the first country globally to do so. Within ten years, hepatitis B infection rates among children dropped from 9.8 percent to below 1 percent. Liver cancer from chronic hepatitis B is now largely preventable in Taiwan.
These examples prove: even in diseases once considered unavoidable in tropical regions, systematic vaccination can transform outcomes. Malaria is harder to combat than viruses because the Plasmodium parasite has multiple life stages. The Lancet finding shows this complexity can be addressed with a vaccine.
From three pilot nations to the continent
After completing MVIP assessments in 2021, the WHO recommended broad implementation across Africa. Since 2023, GAVI, the global vaccine alliance, has financed expansion to more than twenty African countries. A second vaccine is ready: R21/Matrix-M, developed by the University of Oxford and the Serum Institute of India, was WHO-endorsed in 2023 and has simpler cold-chain requirements.
The WHO estimates widespread use of both vaccines could save 40,000 to 80,000 child lives annually. Three practical challenges remain: securing adequate vaccine supplies, maintaining functioning cold chains in rural areas, and improving adherence to the four-dose schedule. The booster dose especially poses an organizational barrier many health systems have yet to reliably overcome.
The Lancet finding offers reason for hope: even with incomplete coverage, the vaccine works measurably. This means health systems not yet operating perfectly can benefit from RTS,S today.