A better way to protect against venomous coral snakes

Every year, more than 2,400 people living in North or South America get bitten by coral snakes. Although rarely lethal, the snakes’ neurotoxic venom can cause several negative symptoms, including muscle weakness, paralysis, and respiratory failure. Existing antivenoms target the toxins expressed by only some of the 70–80 species of coral snakes found in the Americas, says Andreas Hougaard Laustsen-Kiel, an antivenom researcher at the Technical University of Denmark.

So Laustsen-Kiel and his team have been working toward developing an antivenom that’s effective against more species. In a recent study, they’ve identified antibodies that could together avert death in mice injected with venom from two coral snake species(Nat. Commun. 2024, DOI: 10.1038/s41467-024-48539-z).

The team first designed a compound with a sequence similar to several three-finger toxins (3FTxs)—key components of all coral snake venom. The compound is like an average of many 3FTx sequences, says Melisa Benard-Valle, a postdoctoral fellow at the Technical University of Denmark and a study coauthor. The researchers then used a library of antibodies produced by an alpaca and a llama injected with low doses of venoms from African cobras and mambasto identify antibodies that would bind to and neutralize the researchers’ artificially generated toxin. Their search yielded one good candidate.

Next, the team conducted a similar search for antibodies that bind to another set of toxins found in coral snake venom: phospholipases A2. The researchers identified a suitable antibody that would neutralize these toxins. When the two antibodies were combined, the researchers found that mixture protected most mice against the venom of two species: the eastern coral snake, which is found in the southeastern US, and the variable coral snake, which is native to southeastern Mexico and northern Central America.

It’s proof-of-concept research to show that you can make recombinant antivenom that’s not targeting just one species, Laustsen-Kiel says.

It’s elegant work, says antivenom researcher Dayanira Paniagua at the Autonomous University of Baja California, who was not involved in the study.