This animal kills 100,000 people a year. Why can’t we stop it?

There are few animals humans fear more than sharks. This is understandable: Sharks are big, dramatic creatures that have been permanently lodged in our culture as underwater killers since Jaws.

They also kill about six people in a given year. Snakes, on the other hand, kill roughly 100,000. After mosquitoes, which spread diseases like malaria, and humans, who just murder each other, snakes are the deadliest animals on Earth.

The surprise isn’t just that snakes kill so many people, but that the scale of this death and suffering has only recently become clearer. In India, where roughly half of the world’s snakebite deaths happen, official reports had long recorded only about 1,000 snakebite deaths a year. But many victims die in villages, on farms, or on their way to hospitals, and until recently, India did not require snakebite cases or deaths to be systematically reported through its public health system. Researchers using household death surveys and verbal autopsies have more recently estimated that the real number is close to 60,000 a year in India alone.

That gap in data is a big part of the reason why snakebites are so deadly in the first place. Antivenoms exist, and modern antivenoms can work well when given in time. But snake venom differs from one snake species to the next. Different species carry different mixes of toxins that can attack the nervous system, muscles, or tissue in different ways. That means antivenoms often have to be matched to the various snakes found in a given region; an antivenom made for one set of snakes may do little against another. Antivenoms are also expensive to produce and buy, and hard to keep reliably stocked in the rural clinics where they’re needed most.

But medicine is only half the problem. Once a person gets bitten, they have to recognize the danger, reach a hospital or clinic in time, and that clinic has to have an appropriate antivenom in stock, often without anyone knowing exactly which snake bit them. The patient also has to be able to afford the treatment. In poor, rural communities, any of those steps can and often do fail.

And because the people most at risk are also among the least able to pay, there has never been much of a market for better snakebite treatments. In fact, in the last two decades, the market has gotten worse with some manufacturers leaving the field altogether.

But things are beginning to change. Scientists are now running human trials on snakebite treatments other than antivenom, including drugs that may not require cold storage or precise species matching. In February, the World Health Organization issued its first formal blueprint for what next-generation snakebite drugs should look like, including treatments that could be given to victims before they reach a hospital. And in 2024, after years of severe undercounting, India’s health ministry moved to make snakebite a notifiable disease, meaning every case and death has to be reported to public health authorities, and launched a national plan to bring those deaths down.

The field is “witnessing important developments (not sufficient, but important) on various fronts,” José María Gutiérrez, one of the field’s leading authorities on antivenom at the University of Costa Rica, wrote in an email. But whether any of this reaches the villages where most snakebite deaths happen is a separate question.

The basic technology behind antivenoms is more than a century old. In the 1890s, scientists figured out they could inject small amounts of snake venom into animals, usually horses and sheep, wait for their immune systems to produce antibodies, and then harvest those antibodies as treatments.

The manufacturing has gotten a lot more sophisticated since then. The basic animal-based method is still widely used, but modern antivenoms are more carefully purified, processed, and quality-controlled, making them far safer and more effective than earlier versions. But the underlying challenge is still the same. Antibodies have to be matched to specific toxins they are meant to neutralize, and making them at scale is still expensive.

This economic challenge of producing antivenom became most visible in 2014, when Sanofi, a French pharmaceutical company, stopped producing Fav-Afrique, a vital antivenom for sub-Saharan Africa that neutralizes venom from 10 of the most dangerous snakes in the region, because it wasn’t profitable enough. That breakdown was a clear illustration of the underlying problem: snakebite kills at an enormous scale, but mostly among people who have little purchasing power.

But things are beginning to look up. In 2019 the Wellcome Trust, a UK-based philanthropy, announced a roughly $100 million, seven-year program to bring snakebite treatment into the 21st century. A review commissioned by Wellcome found that global funding for snakebite research totaled just $57 million from 2007 to 2018, averaging less than $5 million a year.

The new commitment was the largest infusion of funding the field had ever seen, supporting both the search for new kinds of snakebite treatment and efforts to shore up existing antivenom supply. Some of that money went to Wales-based MicroPharm to restart production of Fav-Afrique, the antivenom Sanofi had abandoned.

The big shift now is that researchers are no longer just trying to make better antivenoms. They’re also trying to develop treatments that could get around some of antivenom’s biggest limitations. And the WHO blueprint gives that shift a more concrete shape. It calls for two kinds of next-gen treatments: drugs that could help in hospitals, alongside or instead of antivenom, and simpler drugs that could be given soon after a bite.

The most advanced new candidate is called varespladib, a drug that can be given as a pill that blocks one of the most damaging families of enzymes in snake venom. In a phase 2 trial, it appeared safe but did not clearly outperform standard care. Researchers now see it more as a field aid.

There are also efforts to repurpose other existing drugs and test them against snakebites, such as marimastat, a cancer drug, and DMPS, a drug used to treat heavy metal poisoning. Gutiérrez says these repurposed drugs are the most promising near-term options because researchers don’t have to start from zero. They have already been tested for other diseases, which means they can move into snakebite trials much faster than brand new drugs. Clinical trials of some of these repurposed drugs are now underway in the US, India, and Kenya. Further out, researchers are also working on new antibody therapies and AI-designed proteins targeted at specific snake toxins.

These drugs are not meant to replace antivenom, which remains quite effective when given in time. But they could finally move the field beyond where it has been stuck for decades.

But the new excitement has yet to pay off. Tim Reed, who runs the Amsterdam-based NGO Health Action International, has long argued that snakebite researchers and funders have chased expensive scientific solutions while community needs go unmet. The pipeline looks promising, he said, but it has yet to bring anything to market. Meanwhile, hundreds of thousands of people have died from snakebite in recent years, and many more have been left with life-changing injuries, “with a disproportionate representation of children,” Reed said.

The new drugs may eventually arrive, but Reed worries that when they do, they may still be priced out of reach for rural patients. Even varespladib, which is cheaper to develop than antibody-based treatments, is being brought forward by a small biotech company that will eventually need to recoup its investment. Whether it will be affordable for a farmer in Bihar or western Kenya is separate from whether it works in trials, yet just as important.

Reed argues that the global snakebite world still underfunds the work that can help people now: prevention, first response, and community education. His organization has kept a small snakebite program going with its own funds, supporting school-based prevention work in Kenya and research in Rwanda. Its Women Champions of Snakebite network is still active, and it has helped launch a Snakebite Community Engagement Network run by people in the Global South. These programs are small, but they are built around the communities where snakebite actually happens.

A better snakebite response would have to do both things at once: Develop better drugs while also funding the community work that can prevent snakebites and deaths now. There’s been real progress, more so in some areas of concern than others, but, as Gutiérrez put it, “there is still a long road to go to give this problem the attention it deserves.”