Next-generation antivenom fights India’s deadliest snakes

The process to make antivenom has barely changed in a century: snakes are milked, their venom is injected into horses, and their antibodies are harvested to form the basis of the product. The resulting treatments are difficult to administer, can trigger severe side effects, and the quality varies from batch to batch. “The big four snakes contribute to 70 per cent of poisonous bites [in India]… so 30 per cent of poisonous snakes are not covered, even to begin with,” said Dr Yogesh Jain, a public health physician in Chhattisgarh state and a member of The Global Snakebite Taskforce. “But there are huge quality and efficacy issues even against these 70 per cent of bites. We’re relying on a 100-year-old technique of getting antivenoms, and at least 50,000 people are dying every year,” he told The Telegraph. “There’s a real need for new technology. We don’t have a safe and appropriate antivenom for the largest majority of people in rural India.” Now, scientists are hopeful that they have developed a potential alternative. In the latest study, published last week, researchers showed that an experimental antivenom cocktail with five components protected mice against lethal doses of antivenom in Indian cobras, even when delayed by up to 20 minutes – a scenario that mimics the real-world lag between a bite and treatment. “If you go 10 years back, people didn’t think you could make sufficiently simple products with new, modern biotechnology that could cover all these different snake venoms,” said Prof Andreas Laustsen-Kiel, head of the Section of Biologics Engineering at the Technical University of Denmark and co-author of the paper. “People simply believed it was too complex, too expensive to manufacture, and so on… But the data we are gathering is convincing enough to say this is something that could make a huge dent in the lost lives and limbs snakebite causes every year.” The antivenom itself was based on lab-made nanobodies – antibodies derived from a group of animals including camels, llamas and some species of shark. Scientists believe their structure means they could be a more potent, more precise, more temperature-stable alternative to man-made monoclonal antibodies – and cheaper to manufacture. “The latest study builds on an earlier discovery of nanobodies that can protect across a broad spectrum of African snakes,” said Prof Nicholas Casewell, director of the Centre for Snakebite Research and Interventions at the Liverpool School of Tropical Medicine, who has previously collaborated with Prof Laustsen-Kiel. “In this paper they have iterated and demonstrated that a narrow number of nanobodies can protect against Indian cobras and king cobras. This demonstration brings the nanobody technology closer to market,” he added. But that is likely still years away, depending on how much funding the researchers can attract. The next steps – a larger animal study, scaling up manufacture, and launching human trials – are expensive. “If money was no issue, we could probably be testing in humans in 1.5 to three years from now,” said Prof Laustsen-Kiel. “But since money is a big issue, it is more likely that human trials won’t be able to start until 2.5 to four years from now. “But I really think that this [study shows] there’s no doubt that biotech can deliver better antivenoms. The question is whether people are willing to fund it,” he said. Protect yourself and your family by learning more about Global Health Security