There really is a purpose for everyone out there. Scientists seem to have developed the most broadly effective snake antivenom seen yet—an antivenom partly derived from the antibodies of a man bitten by snakes hundreds of times.
Researchers at the National Institutes of Health and the company Centivax detailed their work in a study published last week in Cell. In tests with mice, their cocktail protected the animals from 19 of the most venomous snakes in the world. This research could eventually lead to a truly universal antivenom, the scientists say.
Snake antivenom is currently produced by harvesting the antibodies of animals (usually horses) that generate a strong immune response to toxins. While effective, today’s antivenoms have their limitations.
Antibodies to one specific snake or toxin often don’t protect against others, for instance. Mixing different antibodies to create a cocktail can increase the effectiveness of treatment, but it also raises the risk of serum sickness—a harmful immune reaction to the foreign proteins in the antivenom.
Various research teams have been seeking to create a more universal and safer antivenom for quite some time. The study researchers theorized that they could develop one by studying the blood of someone who’s survived being bitten by many different snakes throughout their life. Eventually, they found one such donor: Tim Friede.
Friede is a self-trained herpetologist and venomous snake collector. Nearly 20 years ago, he began letting himself get bitten on purpose to build immunity to snakebites. His first bites, according to NPR, landed him in the hospital with a coma for several days. But Friede recovered and continued his daring endeavor with fewer complications. Over the course of his life, he’s been bitten by venomous snakes some 200 times and he’s further injected himself with more than 700 doses of venom. Realizing that he was now hyper-immune to snakebites, he decided to reach out to other scientists so they could study him. In 2017, he finally connected with Jacob Glanville, the founder of Centivax.
Glanville and his team isolated two specific antibodies from Friede that broadly neutralized many different snake toxins, which they were able to synthesize in the lab. They then made an antivenom cocktail that mixed these antibodies with an experimental molecule that’s previously shown potential as a snake toxin treatment, varespladib.
The team’s three-agent cocktail was administered to mice exposed to the venom of 19 snakes. These snakes all belong to the elapid family of venomous snakes, and are members of the World Health Organization’s Category 1 and 2 snakes (the most medically relevant venomous snakes in the world). The cocktail provided complete protection—meaning 100% survival—for mice exposed to venom from 13 snake species, including several types of cobra and the black mamba, and offered partial protection against six others.
Other research teams are working on their own broadly effective antivenoms. But the researchers say theirs is the first such candidate derived from synthetic antibodies—all thanks to the bravery of Tim Friede, who has since become director of herpetology at Centivax.
“What was exciting about the donor was his once-in-a-lifetime unique immune history,” said Glanville in a statement from Cell Press, the study’s publishers. “Not only did he potentially create these broadly neutralizing antibodies, in this case, it could give rise to a broad-spectrum or universal antivenom.”
Centivax is continuing to develop its cocktail. It’s hoping next to test it in a trial involving snake-bitten dogs in Australia who are brought into veterinary clinics. And the researchers are hoping that they can take things even further by either developing a second cocktail that covers the other major family of venomous snakes, the vipers, or a mega-cocktail that can cover both types of snakes at once.
Should their work pay off, a truly universal antivenom could have major medical benefits, particularly in the developing world where snakebites are much more common. According to the World Health Organization, between two and four million people annually are poisoned by snakebites, while roughly 100,000 die from them every year.
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