• Posted February 23, 2024

Is a 'Universal' Snake Venom Antidote Near?

A “universal” antivenom can block the lethal toxins in the venoms of a wide variety of poisonous snakes found in Africa, Asia and Australia, researchers report.

The antibody protected mice from the normally deadly venom of snakes like black mambas and king cobras, according to findings published Feb. 21 in the journal Science Translational Medicine.

“This antibody works against one of the major toxins found across numerous snake species that contribute to tens of thousands of deaths every year,” said senior researcher Joseph Jardine, an assistant professor of immunology and microbiology at Scripps Research.

“This could be incredibly valuable for people in low- and middle-income countries that have the largest burden of deaths and injuries from snakebites,” Jardine added in a Scripps news release.

More than 100,000 people a year, mostly in Asia and Africa, die from snake bites, researchers said in background notes.

Current antivenoms are produced by immunizing animals with snake venom, and each typically works only against a single snake species.

To develop their new antivenom, the research team compared venom proteins from a wide variety of poisonous snakes, including mambas, cobras and kraits.

Researchers discovered a type of protein called three-finger toxins common to the venom in the snakes they analyzed, which all belonged to the snake family called elapids.

These three-finger toxins are considered highly lethal and are responsible for whole-body paralysis, researchers said.

To work out an antibody to block the venom, researchers combined the genes for 16 different three-finger toxins into the cells of mammals, allowing them to produce toxins in the lab.

The team then tested different human antibodies known to bind to three-finger toxins produced by the many-banded krait, the snake species which had the most similarities to other three-finger toxin proteins.

That narrowed their search down to about 3,800 antibodies, which they then tested against four other variants of three-finger toxins.

Among the 30 antibodies identified by that test, one stood out as having the strongest action against all toxin variants, researchers said.

Researchers then tested the effect of the antibody, 95Mat5, on mice injected with toxins from the many-banded krait, Indian spitting cobra, black mamba and king cobra.

In all cases, mice that received an injection of the antibody were protected from both death and paralysis, researchers report.

While testing the antibody, researchers discovered that it mimicked the structure of the human protein to which three-finger toxins usually bind.

All of the snake species in the analysis were elapids, researchers said. That means it doesn't block the venom of vipers, which are the second group of poisonous snakes.

The research team is now pursuing antibodies against another elapid toxin as well as two viper toxins.

“We think that a cocktail of these four antibodies could potentially work as a universal antivenom against any medically relevant snake in the world,” said lead researcher Irene Khalek, a Scripps Research scientist.

More information

The World Health Organization has more about antivenoms.

SOURCE: Scripps Research Institute, news release, Feb. 21, 2024