According to the 2020 World Malaria Report, in 2019 there were 229 million malaria infections and malaria claimed the lives of 409,000 people, 67 percent of those who died were children under the age five. Africa was by far the most impacted by malaria, with 94 percent of all cases being recorded across the continent.[1] Established malaria prevention measures are working well in many African regions – seasonal malaria chemoprevention (SMC) has been highly successful in recent years at driving down malaria cases and deaths across the Sahel, and hundreds of millions of protective long lasting insecticidal nets (LLINs) have been distributed across sub-Saharan Africa.
However, for the malaria burden to reduce further and, eventually, move towards elimination there is a constant need for innovative tools and technologies. One such innovation has had very early success this year, with long-acting monoclonal antibodies being used by the US National Institute of Health (NIH) to prevent malaria among adults. Monoclonal antibodies are immune system proteins that are created in a laboratory by cloning existing human antibodies. These function in a similar way to antibodies made by a human immune system, recognising and destroying infectious organisms, such as bacteria and viruses. They have been in use therapeutically since the 1990s as a treatment for some cancers and autoimmune diseases and following the findings of a study earlier this year, they were used as a treatment of early stage COVID-19 infection in individuals at high risk for progressing to severe disease and/or hospitalisation.
Now, monoclonal antibodies may have provided a breakthrough in the fight against malaria. The NIH conducted a small, carefully monitored trial which found that one dose of a new long-acting monoclonal antibody safely prevented malaria for up to nine months in people who were exposed to the malaria parasite. This is the first time that a monoclonal antibody has been demonstrated to prevent malaria in humans. Details and results of the trial were published in The New England Journal of Medicine, with the authors concluding, “among adults who previously never had malaria infection or been vaccinated for malaria, the administration of the long-acting monoclonal antibody CIS43LS prevented malaria after controlled infection.”[2]
Malaria Consortium’s Global Technical Director, Dr James Tibenderana, said of monoclonal antibodies, “This is a new and potentially exciting tool in the fight against malaria. Long-acting monoclonal antibodies could extend the options and mechanism for malaria prevention if phase II[3] and III trials demonstrate protective efficacy. The results amongst adults should potentially make it possible in future to investigate the role of long-acting monoclonal antibodies in children. The development of new and scalable tools brings closer the goal of eliminating falciparum malaria.”
[1] https://www.who.int/publications/i/item/9789240015791