Antivenoms in India

Sub: Sci

Sec: Health

Why in News

A recent snakebite tragedy involving a five-year-old girl in Karnataka highlighted India’s ongoing snakebite crisis. With an estimated 58,000 deaths annually, India has been termed the ‘snakebite capital of the world.’ This issue emphasizes the need for accessible and effective antivenoms, innovative treatments, and improved healthcare infrastructure.

What are Antivenoms?

Antivenoms, or antivenins, are life-saving medicines used to neutralize snake venom.
They are produced by:
- Injecting small amounts of snake venom into animals like horses.
- Harvesting the antibodies generated as part of the animals’ immune response.
These antibodies neutralize the venom toxins, allowing the body to recover. However, identifying the snake species and the quantity of venom injected is critical for treatment success.
The antivenom production process was pioneered by French physician Albert Calmette in the 1890s.

Snake venom is a complex cocktail of toxic proteins evolved to immobilize prey and defend against threats.
Toxins and their Effects:
- Hemotoxins: Destroy blood cells and disrupt clotting.
- Neurotoxins: Block nerve signals, causing paralysis.
- Cytotoxins: Dissolve tissue at the bite site.
Antivenoms specifically bind to these toxins, rendering them harmless until the body eliminates them.

Several Indian companies, such as Bharat Serums and Vaccines, Haffkine Bio-Pharmaceutical Corporation, and ViNS Bioproducts, produce antivenoms using this method.
The Irula tribe in Tamil Nadu plays a crucial role by safely extracting venom from snakes, ensuring a steady supply for antivenom production.

Polyvalent Antivenoms (PVAs):

Polyvalent antivenoms (PVAs) are therapeutic agents designed to neutralize the venoms of multiple snake species.
These are immunoglobulin preparations capable of counteracting the toxic effects of venoms from various snake species.
They are particularly valuable in areas with high snake diversity, where identifying the exact species responsible for a bite can be challenging.
Production Process:
- Venoms are extracted from multiple snake species known to cause significant envenomation in a particular region.
Animals, commonly horses, are immunized with incremental doses of these venoms, prompting the production of specific antibodies. After achieving a sufficient antibody response, blood is collected from the immunized animals.
The serum containing the antibodies is processed to isolate and purify the immunoglobulins, which are then formulated into the final antivenom product.
PVAs provide a practical solution in regions with multiple venomous snake species, especially when the offending snake is not identified.
Producing a single PVA is often more feasible than developing multiple monovalent antivenoms, each targeting a specific snake species.
Studies have indicated that certain PVAs can maintain their pharmacological stability and venom-neutralizing ability for extended periods, even decades post-expiry, suggesting the potential for longer

India’s Snakebite Crisis:

India is home to over 300 snake species, of which more than 60 are venomous.
The Big Four snakes—Indian cobra (Naja naja), common krait (Bungarus caeruleus), Russell’s viper (Daboia russelii), and saw-scaled viper (Echis species)—cause the majority of snakebite deaths.
Other venomous species, such as king cobras, hump-nosed vipers, and pit vipers, remain outside the coverage of polyvalent antivenoms (PVAs), leading to ineffective treatment and poor outcomes.
A 2020 study estimated 1.2 million deaths and three times as many disabilities due to snakebites in India between 2001 and 2014.

Advancements in Antivenom Technology:

Researchers are developing synthetic antivenoms using recombinant DNA technology, eliminating the need for animal-derived components.
A team led by Nobel laureate David Baker used Artificial Intelligence (AI) to design synthetic antivenoms with greater efficacy and safety.
Indian scientists at IISc Bengaluru, are mapping venom compositions to create tailored antivenoms for specific regions and species.
Rapid diagnostic tools are being developed to identify venom types, enabling precise and timely treatment.

Indian Cobra (Naja naja):

Recognizable by the distinctive hood mark, often resembling spectacles.
Primarily neurotoxic, affecting the nervous system and potentially leading to respiratory failure.
Widespread across India, inhabiting forests, plains, and urban areas.
Generally shy; raises hood when threatened.

Common Krait (Bungarus caeruleus):

Glossy black or blue-black body with thin white bands.
Contains potent neurotoxins causing muscle paralysis; bites are often painless, leading to delayed treatment.
Prefers fields, low-lying scrublands, and human dwellings.
Nocturnal; seldom aggressive during the day but more active and potentially dangerous at night.

Russell’s Viper (Daboia russelii):

Stout body with a series of dark brown spots bordered by white or yellow.
Hemotoxic, leading to blood clotting disorders, internal bleeding, and acute kidney injury.
Found in grasslands, bushlands, and agricultural fields.
Quick-tempered; hisses loudly when threatened and can strike rapidly.

Saw-Scaled Viper (Echis carinatus):

Small, stocky snake with a pale brown body and darker brown patterns; keeled scales produce a rasping sound when rubbed together.
Potent hemotoxin causing coagulopathy, leading to internal bleeding.
Arid regions, scrublands, and rocky terrains.
Highly irritable; assumes a side-winding motion and produces a characteristic ‘sizzling’ sound when agitated.