In the dry arc of a single malaria season in Mali, two hundred and twenty-five children became part of a quiet human question: could one injection stand between a child and a parasite carried by the mosquito's bite? The answer, published in the New England Journal of Medicine, is a qualified yes, with 77 percent protection among those who received the higher dose. The work, rooted in antibodies first found in a vaccinated volunteer and reshaped by scientists at the National Institutes of Health, reminds us how often the long struggle against disease in Africa's children is measured not in gran
Single Malaria Antibody Dose Shows 77% Protection in Malian Children in Mid-Stage Trial
Nearly 250 million malaria cases and over 600,000 deaths were estimated globally in 2022, mostly among African children.
One injection, six months of malaria season, 77% protection
Mark
Why does a single injection matter so much here?
Mimi
Because the earlier antibody had to be given intravenously. This one is given under the skin, at a single health care visit, and still covered a six-month season.
Luke
Worth noting the trial was 225 children, 75 per group. That's a mid-stage study, so the 77% figure is promising, not final.
Mark
What does the placebo group tell us?
Mimi
That the exposure was real. 81% of those children were infected with P. falciparum and 59% got symptomatic malaria.
Luke
Right, and that's what gives the comparison weight. But the trial covered healthy children aged 6 to 10 only.
Mark
So the people at greatest risk aren't covered yet?
Mimi
Not yet. Infants, pregnant women, and children with severe anemia are the next targets, and a Kenya trial covers ages 5 months to 5 years.
Luke
And nothing in the reporting says how long protection lasts beyond the six months, or when this could be approved. Those are unknown.
Mark
Why does the antibody's origin matter?
Mimi
It came from a volunteer given an experimental vaccine, then was modified to last longer in the blood.
Il Polso
- A single under-the-skin injection shielded most trial children from symptomatic malaria during a six-month high-transmission season.
- Nearly 81 percent of children on placebo were infected, a stark reminder of how relentless the parasite remains in Mali.
- Researchers are now pushing the antibody toward infants, severely anemic children, and pregnant women, where the stakes are sharpest.
- A 12-month Kenya trial in children aged 5 months to 5 years is the next proving ground, and the outcome is still unwritten.
In the dry arc of a single malaria season in Mali, two hundred and twenty-five children became part of a quiet human question: could one injection stand between a child and a parasite carried by the mosquito's bite? The answer, published in the New England Journal of Medicine, is a qualified yes, with 77 percent protection among those who received the higher dose. The work, rooted in antibodies first found in a vaccinated volunteer and reshaped by scientists at the National Institutes of Health, reminds us how often the long struggle against disease in Africa's children is measured not in grand gestures but in the slow patience of trials, doses, and follow-up visits.
Between July 2022 and January 2023, 225 healthy children aged 6 to 10 in Mali took part in a trial that followed them through the country's malaria season. Each received one injection beneath the skin: some a higher dose of an experimental antibody, some a lower dose, and some a placebo. The results, published in the New England Journal of Medicine, show the higher dose was 77 percent effective against malaria disease.
The antibody was developed by scientists at the National Institutes of Health, starting from a volunteer who had received an experimental malaria vaccine. Its design was modified so it would last longer in the bloodstream, and it proved potent enough to be given at a concentration that made a single injection practical. The trial was led by the National Institute of Allergy and Infectious Diseases alongside a university in Bamako.
Among children who received the placebo, 59 percent developed symptomatic malaria. In the higher-dose group, that fell to 19 percent. The authors describe it as the first demonstration that one subcutaneous dose can give high-level protection in children in an area of intense transmission.
The stakes are vast: nearly 250 million malaria cases and more than 600,000 deaths were estimated worldwide in 2022, mostly among African children. Researchers are now testing the antibody in infants, children with severe anemia, and pregnant women, and a Kenya trial is following young children for a year. This was a mid-stage study, and its next chapters are still being written.
Between July 2022 and January 2023, 225 healthy children in Mali, aged 6 to 10, took part in a trial that ran through the country's six-month malaria season. Each child received a single injection under the skin. Seventy-five got 300 mg of an experimental antibody, 75 got 150 mg, and 75 got a placebo. The results, published in The New England Journal of Medicine, show that the higher dose was 77% effective against malaria disease.
The antibody was developed by scientists at the National Institutes of Health. The trial was led by the National Institute of Allergy and Infectious Diseases (NIAID) together with the University of Sciences, Techniques and Technologies of Bamako, through NIAID's International Centers of Excellence in Research program. It ran in two parts: a safety assessment in a small number of adults and children, then the larger efficacy trial.
The numbers are plain. Among children who got the placebo, 81% became infected with Plasmodium falciparum during the six months, and 59% developed symptomatic malaria. In the 300 mg group, 19% developed symptomatic malaria, which works out to 77% protective efficacy. In the 150 mg group, 28% did, for 67% efficacy. The authors say this is the first demonstration that a single subcutaneous dose of a monoclonal antibody can give high-level protection against malaria in children in an area of intense transmission.
The antibody has a short history. In 2020, scientists at NIAID's Vaccine Research Center reported isolating it from a volunteer who had received an experimental malaria vaccine. They modified it with a mutation that extends how long it lasts in the bloodstream. An earlier study in Mali by the same group had tested a previously discovered antibody, CIS43LS, which protected adults against P. falciparum infection when given intravenously. The newer antibody proved more potent in animal studies and could be manufactured at a higher concentration, which is what made an under-the-skin injection possible.
The stakes are large. The World Health Organization estimated nearly 250 million malaria cases worldwide in 2022 and more than 600,000 deaths. P. falciparum caused a majority of those cases and most of the deaths. Most cases and deaths occur among children in Africa, and the parasite is spread by mosquito bites.
Dr. Jeanne Marrazzo, director of NIAID, said a long-acting antibody delivered in a single health care visit, one that quickly provides high-level protection in vulnerable populations, would meet an unmet public health need.
This was a mid-stage trial, and development continues. Researchers are focusing on other high-risk groups: infants and young children, children hospitalized with severe anemia, and pregnant women. A trial in Kenya is testing the antibody in children from 5 months to 5 years old over 12 months. In Mali, another trial is studying women of childbearing potential, preparing the ground for testing in pregnancy. Details of the Mali trial are listed on ClinicalTrials.gov under NCT05304611.
Citazioni salienti
A long-acting antibody given at a single visit that rapidly provides high-level protection in vulnerable populations would fulfill an unmet public health need.— Dr. Jeanne Marrazzo, Director, NIAID (paraphrased)
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