TORONTO (November 10, 2025)—Millions of very young children currently excluded from treatment with the drug ivermectin could be safely included in ongoing campaigns against challenging and often neglected tropical diseases such as intestinal worms, scabies and river blindness, according to results from a clinical trial presented today at the Annual Meeting of the American Society of Tropical Medicine and Hygiene (ASTMH).
"Our double-blind study, which was conducted in Gambia, Kenya and Brazil with 240 participants, found that ivermectin can be given to young children who weigh as little 5 kilograms or about 11 pounds—and that's significant because these children are particularly vulnerable to the many diseases currently treatable by ivermectin," said Kevin Kobylinski, PhD, a University of Oxford honorary visiting research fellow with the Mahidol Oxford Tropical Medicine Research Unit in Bangkok and the lead author of the study.
He said that existing manufacturer labeling restricts giving ivermectin to children under 15 kilograms. Kobylinski said there was interest in revisiting the restriction after an analysis of a large number of ivermectin studies revealed instances in which children who weighed as little as 5 kilograms received the drug without any reports of serious problems. "Outcomes from the Ivermectin Safety in Small Children trial will hopefully provide greater reassurance that ivermectin can be safely used in children weighing less than 15 kilograms," Kobylinski said.
Ivermectin is often administered in what are known as mass drug administration (MDA) campaigns in which the population of entire villages receives the medicine. Kobylinski noted that including small children in these efforts could have a big impact. For example, he said that:
- Small children are most at risk from stunting and cognitive complications caused by infections with ivermectin-susceptible intestinal worms.
- There is evidence that ivermectin can suppress malaria transmission, but only if MDA campaigns reach about 70% of the targeted population, a percentage that is difficult to achieve when excluding children under 15 kilograms.
- Ivermectin MDA campaigns are a mainstay of efforts to eliminate onchocerciasis, also known as river blindness. It can take several years of exposure to onchocerciasis parasites before they affect vision—meaning that delaying treatment until children are older can still prevent blindness. However, infections at a very young age may trigger immune reactions that lead to a form of debilitating onchocerciasis-associated epilepsy known as nodding syndrome.
- Young children are especially vulnerable to scabies , a parasitic infestation that causes intense itching along with skin sores that, as they fester, can lead to bacterial infections and other complications.
"Ivermectin has provided a foundation of some of the most successful interventions in global health, and evidence that it could be safely given to young children could help this work achieve an even greater impact," said ASTMH President David Fidock, PhD, the CS Hamish Young Professor of Microbiology and Immunology and Professor of Medical Sciences at Columbia University Irving Medical Center.
