The World Health Organization (WHO) on Friday recommended widespread use of the RTS,S/AS01 (RTS,S) malaria vaccine among children in sub-Saharan Africa and in other regions with moderate to high P. falciparum malaria transmission. The recommendation is based on results from an ongoing pilot program in Ghana, Kenya and Malawi that has reached more than 900 000 children since 2019.
“This is a historic moment. The long-awaited malaria vaccine for children is a breakthrough for science, child health and malaria control,” said WHO Director-General Dr Tedros Adhanom Ghebreyesus. “Using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year.”
Malaria remains a primary cause of childhood illness and death in sub-Saharan Africa. More than 260 000 African children under the age of five die from malaria annually.
The four-dose vaccine will target children as over three quarters of malaria deaths occur in children under five-years-old, according to a recent report by WHO.
Pilot programs led by the Ministry of Health of Ghana, Kenya and Malawi administered over 2.3 million doses.
Key findings from the pilot countries found a “significant reduction (30%) in deadly severe malaria, even when introduced in areas where insecticide-treated nets are widely used and there is good access to diagnosis and treatment.”
The countries’ modeling estimates also show the vaccine is highly cost effective in areas of moderate to high malaria transmission.
“Countries like Mozambique, Uganda, Zambia and Nigeria have already written officially to express interest for the vaccine,” said John Bawa, Africa lead for vaccine implementation at Program for Appropriate Technology in Health (PATH).
PATH, partners of the vaccine developers say the next step is funding for a broader rollout of vaccines to other endemic countries.
However, David A. Fidock, PhD, a professor of microbiology and immunology at Columbia University in New York City, says a vaccine alone cannot stop malaria infections.
“The vaccine can regain the momentum in reducing disease, but it cannot replace drugs, it’s not effective enough,” he said.
It has been more difficult to develop a malaria vaccine because the disease is caused by parasites, rather than bacteria, meaning parasites need to be during the multiple stages of their life cycles.
“You cannot depend on one vaccine, but you can use multiple vaccines to target different life stages of the parasite. So if you have a parasite that is resistant to a vaccine in one stage, you can target it at another stage,” said Solomon Conteh, a molecular virologist with the National Institute of Allergy and Infectious Diseases.
The RTS,S/AS01 vaccine, brand name Mosquirix, “targets parasites before they can infect the liver, but this is just one stage of the parasite’s complex life cycle,” he said in a report by WebMD.
The malaria parasite has five stages in its life cycle.
The global health community remains hopeful as Mosquirix demonstrates pioneering advancements.
Upon WHO’s recommendation last fall, Dr Matshidiso Moeti, WHO Regional Director for Africa said progress of the malaria vaccine “offers a glimmer of hope for the continent which shoulders the heaviest burden of the disease and we expect many more African children to be protected from malaria and grow into healthy adults.”
Health experts mark the vaccine as a major milestone though there are hurdles ahead.