For the first-time in India, a government body, namely the Indian Institute of Science (IISc), Bengaluru, is producing test batches of non-commercial anti-snake venoms (ASVs) to evaluate the effectiveness of regional anti-venoms in neutralising toxins in region-specific snake bite cases compared to the existing ones. As part of this effort, it is collaborating with one of India’s major anti-venom manufacturers — Bharat Serums and Vaccines (BSV). This may hold the key to finding a more effective ASV, which can contain the high snake bite fatality and related disability rates in India.
The country is home to over 270 species of snakes, 60 of which are venomous. But a four-year, multi-centric study of Evolutionary Venomics Lab under the Centre for Ecological Sciences of IISc found out that the available ASVs are ineffective in treating most region-specific medically important but neglected snake bites. Existing products are only applicable for the Big Four snake species— the spectacled cobra, common krait, Russell’s viper, and saw-scaled viper whose venom collection is limited only to two districts in Tamil Nadu.
Once Dr Kartik Sunagar, who is heading the research, completed the study, IISc tied up with BSV to make test batches of regionally-effective anti-venoms. He said that the new ASVs, for the first time, will offer protection against all clinically important snake species found in the given region, including various species/sub-species of vipers, kraits, and cobras.
Citing an example, he said the ASVs will offer protection against the Sind krait, which the lab’s research has shown to be India’s most toxic snake species. “The range of Sind krait extends all the way from Punjab to northern parts of Karnataka in the west of the country. Considering the toxicity of this snake, and the fact that it is potentially responsible for a large number of deaths in these regions, it is imperative to produce ASVs that are effective against them,” Dr Sunagar added.
The test samples will evaluate the effectiveness of regional ASVs in comparison to conventional products. “For example, this research will inform us whether we need to produce a single anti-venom for western India, from Rajasthan to Karnataka, or if we need to produce specific anti-venoms for specific regions (for example Rajasthan, Maharashtra and Karnataka),” he said. Once proven, IISc will conduct similar studies across other regions of India and identify regions that need a specific antivenom.
According to a BSV statement, “There is an urgent need for the development of region-specific anti-venom in the country. This partnership aims at driving the anti-venom development that will deliver efficient snake bite therapy to save lives, limbs and livelihoods of those in need of the treatment.”
Annually, snakebites cause over 50,000 deaths in India. And four times as many suffer from permanent loss-of-function injuries, such as amputations. The IISc’s study on the spectacled cobra and Russell’s viper, for the first time, highlighted how significant venom variation can be across populations. For example, while some populations of cobras, such as in West Bengal, were extremely neuro-toxic (causing paralysis) the population from Rajasthan was extremely cytotoxic or flesh-dissolving. “This resulted in the anti-venoms completely failing to save mice that were injected with the venom of Rajasthan cobras. In these studies, we found that the anti-venom was particularly ineffective in the northern Indian regions,” Dr Sunagar said.
Asked if they will have to get the nod from the Drugs Controller General of India to roll out the new anti-snake venom in the market, he said that it wouldn’t be applicable to “regional anti-venoms” as the production strategies are identical to the ones that are being used. The only difference between existing and regional anti-venoms would be the source of venoms.
“Hence, human clinical trials are not necessary for regional anti-venoms. While I say that, it is important to clinically test the effectiveness of Indian anti-venoms – regional or conventional – through human clinical trials as they inform us of their real-world performance. This is even more important considering that Indian anti-venoms have never been clinically validated in humans,” he said.