2023-06-26 21:00:59
Over the past three years, the Covid-19 pandemic has made headlines and generated a great deal of research. All over the world, specialists have channeled their resources and technical means in this direction. Even if the headlines have partly turned away from the subject, Covid-19 remains a global priority, sometimes to the detriment of infectious diseases linked to poverty or which primarily affect countries in the global South. It is estimated that in 2021 malaria affected 247 million people worldwide, of whom 619,000 lost their lives – the vast majority of children in sub-Saharan Africa.
However, great progress has been made, we can prevent malaria and cure it. For example, to protect once morest Anopheles (the mosquito that transmits malaria), the World Health Organization has just recommended the use of mosquito nets treated with two new types of insecticide, one more effective by its lethal effect, the other which prevents the growth and reproduction of the mosquito.
Cheap antimalarials are another important tool. In 2021, some 45 million children aged 3 months to 5 years received tablets to prevent the disease during the months when malaria is most devastating – at a cost of less than 4 dollars per month per person . The recent announcement of an innovative vaccine, Mosquirix (or RTS, S) from the GSK laboratory, also brings hope, despite its relatively high cost (regarding 40 dollars per child in the first year).
However, malaria remains a threat to public health. Even following a $26 billion investment to fight the disease in sub-Saharan Africa, the number of cases increased slightly between 2000 and 2019 (although the number of deaths decreased). New prevention measures are needed, especially for children. The next innovations should be inspired by one of the results of the numerous studies on Covid-19: the enormous potential of monoclonal antibodies.
Made in the lab, these drugs are copies of proteins that the immune system produces to attack a specific outside invader. Monoclonal antibodies are already a powerful weapon once morest cancer and autoimmune diseases such as rheumatoid arthritis and lupus. Although not often used prophylactically, they show great promise in preventing Covid-19 and respiratory syncytial virus (RSV). In addition, their high selectivity allows them to discriminate between closely related molecular targets, which reduces their adverse off-target effects. This makes it a drug with an appropriate safety profile for children and other at-risk populations.
Led by Robert Seder, a research group from the American Institutes of Health (NIH) has identified two antibodies that may block CSP-1 (the protein that the malaria parasite uses to invade liver cells at the start of infection) and thus prevent malaria. The more advanced of the two antibodies, L9LS, is currently being tested for safety and efficacy in children in Mali and Kenya. The Malian study evaluates its effectiveness in the context of seasonal malaria and the study
Kenya covers an area where the infection is endemic.
Monoclonal antibodies might be a game-changer in malaria prevention and a step towards its long-standing goal of eradication. The current generation of antimalarial antibodies have been modified so that a single dose protects a child for at least three months. Clinical trials will make it possible to evaluate the quality and exact duration of this protection and will provide useful indications on the improvements to be made so that an annual injection is sufficient.
Although antibodies have a reputation for being expensive (in Europe and the USA those used to treat cancer cost more than $20,000 a month), increasing the effectiveness of this cutting-edge treatment might reduce the costs of significantly. According to some estimates, a one milliliter injection of the antibody being tested in Mali and Kenya might protect a child at a cost of just $5-10.
To date, demand for monoclonal antibodies comes mainly from rich countries, Africa only accounts for 1% of global sales. This disparity highlights the need to work with national regulatory bodies to ensure that the production of these molecules meets public health concerns, and that in the longer term countries affected by malaria participate. This production is both complex and highly regulated, but investing now in this area would be an asset for developing countries affected by endemic malaria.
Monoclonal antibodies are perhaps the new frontier in the fight once morest malaria. The message must be passed on: all stakeholders, whether States, universities or industry, must coordinate their efforts and raise awareness; they should also encourage the development of this type of biological tool to fight once morest all infectious diseases.
We are only at the beginning of a long road: the first generation of antimalarial antibodies will not be available until 2027 at the earliest. Along with the mosquito nets, drugs and vaccines that are being worked on, they are one of the most promising weapons in the fight once morest the killer of children, malaria. Clinical trials will tell us if they meet our expectations. If successful, let’s be ready to use them.
*Cristina Donini is vice president of the Medicines for Malaria Venture (MMV) Foundation’s Leadership and Strategy program and Doreen Akiyo Yomoah is MMV’s communications manager.
Translated from English by Patrice Horovitz.
© Project Syndicate, 2023.
Over the past three years, the Covid-19 pandemic has made headlines and generated a great deal of research. All over the world, specialists have channeled their resources and technical means in this direction. Even if the headlines have partly diverted from the subject, the Covid-19 remains a global priority, sometimes at…
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