The world now has a new powerful tool in the fight against malaria. The World Health Organization (WHO) recommended the widespread use of the malaria vaccine RTS,S/AS01 (RTS,S) for children in sub-Saharan Africa and in other regions with moderate to high spread of the disease from Plasmodium falciparum, the most deadly of malaria parasites.
“The long-awaited malaria vaccine for children is a breakthrough for science, child health, and malaria control,” said the WHO’s director-general, Tedros Adhanom Ghebreyesus, PhD, in a statement. “Using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year.”
Malaria continues to be the main cause of childhood illness and death in sub-Saharan Africa. More than 260,000 African children under age 5 die from the disease annually. Plasmodium falciparum is the most life-threatening of the five different types of malaria parasites. Stanford Health Care says that patients with severe falciparum malaria may develop liver and kidney failure, convulsions, and coma.
“[The] recommendation 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,” said Matshidiso Moeti, MBBS, the WHO’s regional director for Africa, in a press release.
The WHO gave its approval last week on the basis of results from ongoing pilot programs in Ghana, Kenya, and Malawi that have reached more than 800,000 children since 2019. The health organization cited a 30 percent reduction in deadly severe malaria, even when the vaccine was introduced in areas where insecticide-treated nets are widely used and access to diagnosis and treatment is good.
The journal Nature called the efficacy of the vaccine “modest” in that it prevented just 3 out of 10 severe malaria cases after a series of four injections in children younger than 5. Still, even at 30 percent effectiveness, some modeling suggests that it could save the lives of tens of thousands of children.
“The new vaccine is imperfect in that it provides partial protection and takes considerable organization to administer because it requires four injections in young children,” says William Schaffner, MD, an infectious-disease specialist and a professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville. “That is why large field studies in Africa were undertaken. They showed that the vaccine was acceptable to parents and children and that malaria was notably reduced — a success!”
Dr. Schaffner says the next step is to establish even larger, scaled-up programs.
Called Mosquirix, the vaccine produced by GlaxoSmithKline Biologicals has been in development since the mid-1980s. The CDC noted that several challenges had to be overcome to reach this point, including the lack of a traditional market, few developers, and the technical complexity of developing any vaccine against a parasite.
“Malaria parasites have a complex life cycle, and there is poor understanding of the complex immune response to malaria infection,” writes the federal health agency. “Malaria parasites are also genetically complex, producing thousands of potential antigens [foreign invaders in the body].”
GlaxoSmithKline has committed to donate up to 10 million malaria vaccine doses for use in the pilots, and to supply up to 15 million doses annually, following a recommendation and funding for wider use. The company has committed to make the 15 million annual doses available at no more than 5 percent above the cost of production.
“As this first vaccine is deployed, scientists continue lab work to create an even better malaria vaccine,” says Schaffner. “In the meantime, this new vaccine should be used to prevent as much life-threatening malaria infection as possible.”