Guwahati: A new antivenom developed specifically against two venomous green pit vipers found in Northeast India has demonstrated stronger venom-neutralising activity than the polyvalent antivenom currently used across the country, according to a new study.
Published in the International Journal of Biological Macromolecules, the study evaluated a bivalent antivenom (Bi-AV) developed using the venoms of Trimeresurus erythrurus, commonly known as the red-tailed bamboo pit viper, and Trimeresurus popeiorum. Both species are found in Northeast India.
Researchers Rahul Kumar, Salima Siddika, Priyanka Gogoi, Nitin Salvi, Milind V. Khadilkar, M. Firoz Ahmed, Hmar Tlawmte Lalremsanga, Bhargab Kalita and Ashis K. Mukherjee developed the experimental antivenom using snake venom samples collected in Mizoram.
Laboratory and preclinical tests showed that the Bi-AV had greater ability to recognise and neutralise the venoms than India’s commercially available polyvalent antivenom.
The findings are significant because the antivenom routinely used in India is produced primarily against the country’s “Big Four” venomous snakes, the Indian cobra, common krait, Russell’s viper and saw-scaled viper. These species do not account for the wider diversity of medically important snakes found in Northeast India.
The researchers found that the experimental antivenom was particularly effective against venom components linked to haemorrhage, tissue damage and disruption of blood coagulation.
The team also conducted experiments in mice. The Bi-AV was associated with improved survival and reduced venom-induced effects compared with the commercially available antivenom during the preclinical tests.
Another notable finding emerged when the researchers tested the formulation against venom collected outside its original source region. The Bi-AV successfully neutralised T. popeiorum venom obtained from Meghalaya, indicating that its potential activity may extend across different geographical populations of the species.
The finding could be relevant to Northeast India, where snake populations and venom composition can vary geographically. Such variation can affect how effectively antivenoms developed using venom from other regions work against local snakebite cases.
The study also highlights the burden of pit viper envenomation in the Northeast. A previous hospital-based study in Assam recorded 92 cases of pit viper envenomation between April 2018 and August 2022, with a substantial proportion of patients developing abnormalities in blood clotting.
For clinicians treating snakebite in the region, the availability of an antivenom is therefore only part of the challenge. Its ability to effectively neutralise the venom of the species responsible for a bite is also important.
The researchers argue that the findings support further work on region-specific and species-targeted antivenoms, rather than relying exclusively on formulations developed around snake species found predominantly in other parts of India.
The study also underlines the need for systematic collection and characterisation of snake venoms from Northeast India. Better understanding of regional venom diversity could help researchers design antivenoms that more closely correspond to the species responsible for snakebite cases in the region.
However, the findings do not mean that the new Bi-AV is currently available for routine treatment. The research remains at the laboratory and preclinical stage, and additional studies, including clinical evaluation, would be required before the antivenom could potentially be used in human patients.
The research nevertheless points towards a possible new approach to snakebite treatment in Northeast India, developing antivenoms based more closely on the venomous snake species that are actually responsible for bites in the region.