In a recent breakthrough, scientists from IISc Bengaluru’s Centre for Ecological Sciences (CES) and the Technical University of Denmark (DTU) have created an antivenom that could potentially be used to treat snakebites from the diverse cobra species of India. The scientists published their discoveries in the journal Science Translational Medicine, in a research paper titled “Oligoclonal nanobody-based recombinant antivenom protects mice challenged with venom from cobras and king cobras from India”, last month.We explain how different cobra venoms affect humans, the challenges in treating snakebites, and how the CES-DTU collaboration developed the new antivenom.While there are many species of cobra in India, they generally kill their prey using “neurotoxins” in their venom that paralyse their prey and stop them from breathing. Cardiac issues and other side effects have been observed in some cases of attacks on humans.In 2024, a Union Health Ministry statement had estimated the annual snakebite fatalities at 50,000. The spectacled cobra (Naja naja), one of India’s “Big Four” venomous snake species (the others being the common krait, the Russell’s viper, and the saw-scaled viper), accounts for at least 12.5% of these snakebite deaths — this number could be higher, as the snake is not always identified by the victim.But it is just one of several cobra species in India — different species have different kinds of venom. In fact, venom from the same kind of cobra might vary in composition for cobras from different locations.Also in Explained | Centre wants states to make snakebites notifiable disease: why, what this meansThis poses a challenge when using antivenom. For example, while the Polyvalent antivenom is used in India to counter the venom of the Big Four snakes including the spectacled cobra, this would not have an effect in the case of king cobra venom. Even amongst king cobras, an antivenom developed for Thai cobras might not work on Indian king cobras.Treatment is also complicated by the fact that rural victims often do not reach healthcare centres in time, or end up at centres which may not have the required antivenom.Story continues below this adAccording to Kartik Sunagar, an associate professor at CES who is part of the collaborative effort, antivenom treatment has essentially remained the same for the past century.How was the new antivenom developed?Previously, Danish scientist Andreas Laustsen and his colleagues at DTU had tested a new method on certain African snakes. They took the blood of domesticated animals such as alpacas and llamas, which had been exposed to the venom of these snakes.Then, they extracted the antibodies that were formed. According to an IISc statement, the Danes “displayed the antibodies on bacteriophages, exposed them to venom from various snake species, and isolated specific antibody fragments that could bind to and neutralise the toxins in the venom”. A bacteriophage, also called a phage, refers to a virus that infects and replicates within bacteria.Also read | A simple night-time habit to prevent snake bites: Romulus and Zai Whitaker share practical adviceA similar process was applied to create an “antibody cocktail” from India’s different cobra species. This was then tested on mice, which had been injected with venom from spectacled cobras, monocled cobras, and two species of king cobras. Even 30 minutes after venom injection, the antibody cocktail was able to save the test mice from death.How could the discovery be applied in the future?Story continues below this adPreviously, such use of antibodies to counter venom in mice tests required a large amount of antibodies, which might mean that a huge dose would be needed for humans. But the current research, Sunagar said, “showed that it is possible to neutralise venom using very small amounts of carefully selected and engineered antibodies”. This could potentially help address some of the cost and safety concerns associated with administering large quantities of antibodies, he added.Further, such a method could be used to create cures for snakebite venom of species across the world. The IISc statement quoted Laustsen as saying, “This work provides a blueprint for how recombinant antivenoms can be tailored to different regions of the world by targeting the toxin families that drive disease in local snake species.”