A Five-Nanobody Antivenom From IISc and Denmark Protected Mice Against the Venom of Spectacled Cobras, Monocled Cobras and Both Indian King Cobra Species

On 9 September 2026 the Indian Institute of Science (IISc) in Bengaluru announced an antivenom built from five nanobodies that kept mice alive after they were injected with venom from the spectacled cobra, the monocled cobra and both Indian king cobra species. Nanobodies are small antibody fragments that can be made in microbial cells, so producing them does not depend on repeatedly immunising horses. The work comes from IISc’s Centre for Ecological Sciences and the Technical University of Denmark (DTU), and it was published in Science Translational Medicine.

The IISc release opens with the scale of the problem: India reports nearly 50,000 snakebite deaths every year, which it describes as the most of any country.

Five nanobodies, first found against African snakes

Each snake species makes its own mix of toxins, and the IISc release says that is what makes a single treatment hard to design. Current antivenoms are made from animal plasma. The paper’s abstract describes them as equine plasma-derived and lists variable efficacy, safety concerns and limited cross-neutralisation of venoms from different regions among their drawbacks. The release adds batch-to-batch variability, high cost and low yields of active antibody.

The five nanobodies came from earlier work at DTU. Andreas Laustsen’s group immunised an alpaca and a llama with the venoms of 18 African snakes, built phage display libraries (collections of viruses that each carry one antibody fragment on their surface, so the ones that stick to a toxin can be fished out), and mixed eight nanobodies into a single antivenom. That study, in Nature on 29 October 2025, reported that the mixture prevented death in mice from the venoms of 17 African elapid snake species and did better than a plasma-derived antivenom, Inoserp PAN-AFRICA.

Kartik Sunagar, an associate professor at IISc’s Centre for Ecological Sciences, worked with Laustsen to test whether the same antibody fragments would also recognise Indian venoms. The paper’s abstract says the five had already been identified and tested against matching toxin families from African snakes. They target three families that the abstract calls prevalent in cobra and king cobra venoms: the alpha-neurotoxins, the cytotoxins and the phospholipases A2. The IISc release says the antibodies neutralised related toxins made by Indian snakes.

What the mice were given and what happened

In the lab, the IISc release says, the cocktail neutralised venom activity and stopped venom from binding to its target receptor. Drug Discovery News, summarising the paper, reports that all five nanobodies bound venom from five populations of spectacled cobra (Naja naja), two of monocled cobra (Naja kaouthia) and both king cobra species, Ophiophagus kaalinga and Ophiophagus hannah. The same report says the nanobodies did not bind unrelated molecules such as DNA, insulin or human serum albumin, and stayed stable after 16 hours at 40 degrees Celsius.

The mouse tests used two designs, a preincubation model and a rescue model, in which the antivenom is given after the venom. The abstract says the cocktail prevented death from monocled cobra venom, from king cobra venom of both species collected in the Western Ghats and in Northeast India, and from pan-Indian populations of spectacled cobra. Drug Discovery News reports that every treated mouse survived the 24-hour observation period in both models, while animals given venom alone died within 15 to 60 minutes depending on the experiment.

The IISc release says the cocktail saved mice even 30 minutes after venom injection. Sunagar is quoted: “Even mice that were paralysed or had typical neurotoxic symptoms would revert to a completely asymptomatic state.”

On dose, the release says earlier work often needed relatively large amounts of antibody to neutralise venom in mice. Sunagar’s reading is that this study shows very small amounts of carefully selected antibodies can do it, which could help with cost and safety if the approach reaches people. Drug Discovery News adds that protection held when the antibody dose was cut to a 1:1 molar ratio with the toxins.

The numbers behind the project

The Press Information Bureau’s release of 12 March 2024 puts India’s toll at around 50,000 deaths from an estimated 3 to 4 million snakebites a year, about half of all snakebite deaths worldwide. The World Health Organization’s fact sheet quotes a higher long-run average: revised estimates of as many as 1.2 million Indian deaths from 2000 to 2019, or 58,000 a year.

That figure comes from the eLife paper by Wilson Suraweera and colleagues, which analysed 2,833 snakebite deaths among 611,483 verbal autopsies (interviews with families about how a person died) in the Million Death Study from 2001 to 2014, then added a literature review. The authors report that most deaths happened at home in rural areas and that about 70 percent were in eight higher-burden states.

Hospital counts are lower. The PIB release notes that Central Bureau of Health Investigation reports for 2016 to 2020 average about 2,000 deaths a year, and says only a small proportion of victims report to clinics and hospitals.

The PIB release adds that around 90 percent of Indian snakebites come from four snakes, the common krait, the Indian cobra, Russell’s viper and the saw-scaled viper, and that the polyvalent antivenom now in use, which contains antibodies against all four, is effective in 80 percent of cases. The Indian cobra, which is the spectacled cobra, is one of those four, and the new mixture is aimed at that group and at king cobras.

Where it fits in the national snakebite plan

The Union Health Secretary launched the National Action Plan for Prevention and Control of Snakebite Envenoming (NAP-SE) on 12 March 2024, with a stated aim of halving snakebite deaths by 2030 through a One Health approach, meaning human, animal and wildlife health planned together. The same day a snakebite helpline, 15400, was announced for a pilot in Puducherry, Madhya Pradesh, Assam, Andhra Pradesh and Delhi. The WHO roadmap sets a matching goal of a 50 percent cut in snakebite deaths and disability by 2030.

The plan document, written by the Centre for One Health at the National Centre for Disease Control, lists nanobodies among the next-generation antivenom methods now in development, alongside recombinant monoclonal antibodies, small molecule inhibitors, aptamers and synthetic peptides. The IISc paper adds an Indian data point to that list.

An Indian, Danish and Thai team

The author list shows who did what. The IISc Evolutionary Venomics Lab supplied three authors, including Sunagar. DTU’s Department of Biotechnology and Biomedicine supplied most of the others, including Laustsen and Anne Ljungars. One author, Suthimon Thumtecho, also holds an affiliation at Chulalongkorn University and King Chulalongkorn Memorial Hospital in Bangkok. H T Lalremsanga works in the zoology department at Mizoram University in Aizawl, in the northeastern state profiled in Mizoram at a glance.

The paper’s funder records list Wellcome and the DBT/Wellcome Trust India Alliance, among others. Laustsen says in the release that the work offers a blueprint for how recombinant antivenoms can be tailored to regions by targeting the toxin families of local snakes. Ljungars says solving a global health problem like snakebite takes this kind of collaboration across disciplines.

For how Indian manufacturers already make and release biological products at scale, see how a vaccine gets made the Indian way.

What was measured, and what comes next

The study measured whether mice given cobra or king cobra venom survived when treated with the five-nanobody cocktail, and the evidence comes from lab assays and mice, with no large-animal or human data yet.

The cocktail was designed against cobra and king cobra toxins. Drug Discovery News reports that it did not protect against venom from the common krait, which is rich in beta-bungarotoxins, a toxin class the mixture was not built to target. The IISc release says more antibody components can be added to extend protection to other medically important snakes. Drug Discovery News quotes Ljungars on the next steps: large-animal studies of how the antibodies spread through tissue and clear from the body, along with safety data.

The accounts also give different delay times. The IISc release gives 30 minutes after venom injection, while Drug Discovery News gives five minutes for the rescue model and up to 20 minutes for delayed dosing, so the paper’s methods are the place to check the exact protocol. Outlook India’s report says protection shown in mice does not mean the treatment is ready for people.

The national plan’s own table of challenges states that most studies of next-generation therapies are not clinically validated, and it recommends that funding be allocated to research institutes for that work.