Researchers develop a nanobody cocktail that neutralised most tested African elapid venoms in mice
Venomous snakebites affect hundreds of thousands of people worldwide each year, and treating the many different venom types quickly and effectively remains a major challenge. An international team led by researchers at the Technical University of Denmark (DTU) reports progress toward a broad-spectrum antivenom: a cocktail of tiny antibody fragments called nanobodies, derived from alpacas and llamas, protected mice from lethal doses of 17 out of 18 African elapid venoms tested.
Snakes are remarkable animals: of roughly 4,000 known species, about 600 are venomous. In many parts of the world—especially sub-Saharan Africa—snakebite is a serious public-health problem: an estimated 300,000 bites occur there every year. Current antivenoms are typically produced by immunising large animals such as horses, collecting their blood and purifying antibodies. Those products can save lives but vary in quality between batches and sometimes cause immune reactions in patients.
Why camelid nanobodies?
Camelids (alpacas, llamas and relatives) produce a special type of antibody fragment that is much smaller and simpler than conventional antibodies. The DTU-led team immunised alpacas and llamas with venoms from 18 medically important African elapid snakes—including the black mamba, Nubian spitting cobra and Cape cobra—using a gradually increasing 60-week schedule. The animals produced nanobodies that the researchers selected, cloned and combined into a therapeutic cocktail.
“This method makes it possible to select and copy effective antibody fragments (nanobodies) and later produce them on a large scale and with consistent quality,” said DTU co-author Andreas Hougaard Laustsen-Kiel. “This means that we would be able to produce the antivenom in large quantities without compromising on quality.”
Nanobodies offer several practical advantages over conventional antivenoms: they are more stable (which can lower production and storage costs), their small size helps them penetrate tissues more rapidly, and they can be engineered to neutralise different toxin types, including both neurotoxins and cytotoxins that commonly coexist in venoms.
Key results and caveats
- The nanobody cocktail protected mice from lethal doses of 17 of the 18 elapid venoms tested, demonstrating broad coverage within that snake family.
- All experiments reported so far were performed in mice; human safety and efficacy are not yet established and will require further preclinical work and clinical trials.
- The study focused on elapids (cobras, mambas and related snakes). Viperid venoms (from vipers and rattlesnakes), which include different toxins and cause many other deadly bites, were not covered by this cocktail. Researchers hope to apply the same approach to viper venoms and potentially combine elapid- and viperid-targeting products into a true broad-spectrum antivenom.
While staying cautious around venomous snakes remains essential, this work is a promising step toward more stable, scalable and broadly protective antivenoms. If reproduced in further studies and proven safe in humans, camelid-derived nanobody antivenoms could improve treatment access and outcomes where snakebite burden is high.
Source: DTU-led study published in Nature. Results reported in mice; clinical development is required before human use.
