Biting Back

A reptile specialist extracts venom from a deadly Eastern tiger snake to create antivenom—a lifesaving snakebite treatment.

A snake’s bite can be deadly. If a victim receives antivenom—a medicine that counteracts the effects of a snake’s venom—quickly enough, though, they might have a chance of survival. But around the world, antivenoms are in short supply. That’s because the medicines require collecting venom from actual snakes, making them expensive and difficult to make. To solve the shortage, scientists are working to engineer artificial venom and antivenom molecules—two or more atoms bonded together.

Lifesaving Medicine

Each year, about 90,000 people around the globe die from snakebites. Many of those victims live in the developing world. The largest number of fatal bites occurs in Southeast Asia, India, Brazil, and Africa. In these poorer counties, antivenoms are expensive and not readily available.

Pharmaceutical companies have difficulty making large amounts of antivenom because it requires raising snakes in captivity. Each snake provides only a small amount of venom at a time. Also, companies must make many types of antivenom because each is effective against only one particular type of snake. Because manufacturing the medicines is hard and not that profitable, fewer and fewer companies are choosing to sell them.

That’s why Paulo Lee Ho, a biochemist at Butantan Institute in São Paulo, Brazil, has been searching for better ways to create treatments for snakebites. “We need a new way to meet the demand for antivenom,” he recently told Nature magazine.

Making Antivenom

For more than a century, scientists have been making antivenom by first injecting a tiny, harmless dose of venom into a large animal, like a horse. This triggers the animal’s body to produce antibodies. These specialized molecules attack and disable the venom’s toxins. The antibodies are removed from the horse’s blood and given to snakebite victims as antivenom.

Last month, Ho reported making artificial DNA—the molecule that carries hereditary information—that triggered the production of antibodies in mice against deadly coral snake venom. Other scientists recently engineered artificial pieces of antibodies that combatted the effects of pit viper bites.

Researchers hope these new methods could make treatments more accessible to snakebite victims and, as a result, save more lives.

“There has been significant, rapid progress in this area, but it needs to be fast,” says Robert Harrison, the head of the Alistair Reid Venom Research Unit at the Liverpool School of Tropical Medicine in England. “There are too many people dying from what is essentially a preventable disease.”