Malaria killed more than 620,000 people in 2020 and sickened 241 million, mostly children under 5 in Africa. The World Health Organization is releasing the first approved malaria vaccine for children, but it is only about 30% effective and requires four doses. The new study tried a very different approach — giving people a large dose of laboratory-made malaria-fighting antibodies instead of depending on the immune system to produce enough of those same infection-blockers after vaccination. “The available vaccine does not protect enough people,” said Dr. Kassoum Kayentao of the University of Sciences, Techniques and Technologies in Bamako, Mali, who helped lead the study in the villages of Kalifabougou and Toronto. In these villages during the malaria season, other research has shown, people are bitten by infected mosquitoes an average of twice a day. The experimental antibody, developed by researchers at the US National Institutes of Health, was administered by IV — difficult to administer on a large scale. However, the encouraging findings bode well for an easier-to-administer version of the shot from the same scientists that is in early trials in infants, children and adults. The US government’s research was published Monday in the New England Journal of Medicine and presented at a medical meeting in Seattle. The antibody works by breaking the life cycle of the parasite, which is spread through mosquito bites. It targets immature parasites before they enter the liver where they can mature and multiply. It was developed from an antibody obtained from a volunteer who received a malaria vaccine. The study involved 330 adults in Mali who received either one of two different doses of antibodies or a sham injection. All were tested for malaria infection every two weeks for 24 weeks. Anyone who got sick was hospitalized. Infections were detected by blood testing in 20 people who received the highest dose, 39 people who received the lowest dose, and 86 people who received the placebo. The highest dose was 88% effective, compared to placebo. The lowest dose was 75% effective. Protection can last during several months of a malaria season. The idea is to someday use it alongside other malaria prevention methods, such as malaria pills, mosquito nets and vaccines. The cost is uncertain, but one estimate suggests that laboratory antibodies could be given for as little as $5 per child per malaria episode. Laboratory antibodies are used to treat cancer, autoimmune diseases and COVID-19, said Dr. Johanna Daily of Albert Einstein College of Medicine in New York, who was not involved in the study. “The good news is that we now have another immune-based treatment to try to control malaria,” Daily said.
The Associated Press Health and Science Section is supported by the Howard Hughes Medical Institute Science Education Division. AP is solely responsible for all content. Carla K. Johnson, The Associated Press
