Health/Sci-TechLifestyleVOLUME 19 ISSUE # 17

We’re finally close to a universal antivenom, say researchers

If you’re bitten by a venomous snake, the medicine you need is antivenom. Unfortunately, antivenoms are species specific, meaning you need to have the right antivenom for the snake that bit you. Most of the time, people have no idea what species of snake has bitten them. And for some snakes, antivenoms are simply not available.

New research my colleagues and I conducted provides a significant step forward in enabling the development of an antivenom that will neutralize the effects of venom from any venomous snake: a so-called “universal antivenom”.

In our paper, published in Science Translational Medicine, we describe the discovery and development of a laboratory-made antibody that can neutralize a neurotoxin (a toxin that acts on the nervous system) found in the venom of many types of snake around the world.

Venomous snakes kill as many as 138,000 people each year, with many more survivors suffering from life-changing injuries and mental trauma. Children and farmers make up the bulk of the victims. The active ingredients in antivenoms are anti-toxin antibodies. They are made by injecting horses with small quantities of snake venom and harvesting the antibodies. This method of making antivenom has remained the same for over a century — and it has substantial drawbacks.

In addition to antivenoms being species specific, they are also not very potent, so you need lots of antivenom to neutralize the venom from a bite. Also, because antivenoms are made in horses, you are highly likely to experience severe side-effects when administered, as your body’s immune system will detect and react to the “foreign” horse antibodies circulating in your bloodstream.

Antibodies that are made in the laboratory using genetically modified cells are routinely used in humans to treat cancers and immune disorders. A long-held hope is that the technology used to produce these antibodies can be used to make antivenoms and eventually replace traditional antivenoms, thereby solving many of the issues current antivenoms face.

The antibodies in lab-made antivenoms could be “humanized”, a process that tricks your immune system into thinking foreign antibodies are your own antibodies. This might reduce the rate of severe side-effects that are commonly encountered with horse-derived antivenoms.