ANTIVENOMS
1. Context
A landmark 2020 study by researchers from Canada, India, and the U.K. estimated that between 2001 and 2014, a staggering 1.2 million snakebite deaths and three-times as many cases of disability occurred in India
2. What are Antivenoms?
- Antivenoms, also known as antivenins, are critical medicines designed to treat snakebites. They are developed by introducing small doses of venom into animals, typically horses, which stimulate the production of antibodies as part of their immune reaction. These antibodies are then used to create antivenoms.
- Snake venom is among nature’s most potent weapons, consisting of a highly specialized mix of toxic proteins evolved to immobilize, and sometimes digest, prey or defend against threats.
- When a snakebite delivers a significant amount of venom, its toxins can cause severe damage to the human body. Haemotoxins attack blood cells and disrupt coagulation, neurotoxins interfere with nerve signals and induce paralysis, and cytotoxins break down tissue around the bite. Without timely medical care, these effects can often be fatal.
- Antivenoms play a crucial role in countering venom’s effects. They neutralize venom toxins by binding to them, enabling the body’s natural systems to safely eliminate the toxins over time. However, for treatment to be effective, it is essential to identify the snake species responsible for the bite and estimate the venom’s quantity.
- In India, polyvalent antivenoms (PVAs) are used to target multiple snake species. However, their effectiveness can vary against rarer species. Advancing treatment options requires a deeper understanding of venom’s complexity and the processes involved in producing antibodies
3. How does antivenom work?
- The creation of antivenom showcases a blend of human innovation, the resilience of animals, and the principles of immunology, tracing its origins to the groundbreaking work of French physician Albert Calmette in the 1890s. Calmette pioneered the use of horses in antivenom production, a method still in practice today.
- The process begins with trained experts capturing healthy, mature venomous snakes from the wild and extracting their venom through a procedure known as “milking.” This venom is then used to immunize horses by administering gradually increasing doses over several weeks.
- The amount of venom injected is carefully regulated: insufficient doses elicit a weak immune response, while excessive doses may harm the horse.
- As the horses' immune systems respond, they produce antibodies specifically designed to neutralize the toxins in the venom. These antibodies are highly specialized, akin to a lock-and-key mechanism, targeting the exact toxins introduced.
- This process is similar to how humans build immunity to familiar pathogens, such as those causing the flu or common colds, through repeated exposure or vaccination. Once the horses have developed a strong immune response, the antibodies are extracted from their blood, purified, and formulated into antivenom.
- In India, several companies, including Bharat Serums and Vaccines, Haffkine Bio-pharmaceutical Corporation, and ViNS Bioproducts, produce antivenom using this method. A vital part of this process is the contribution of the Irula tribe in Tamil Nadu.
- Renowned for their expertise in safely capturing snakes and extracting venom in controlled conditions, the Irular people provide a reliable supply of high-quality venom. Their skills are indispensable to the antivenom production chain, ensuring its continuity and effectiveness
4. How Common Snakebites are in India?
- India is home to over 300 snake species, with more than 60 of them being venomous, varying from mildly to highly toxic. The "Big Four" snakes — the Indian cobra (Naja naja), common krait (Bungarus caeruleus), Russell’s viper (Daboia russelii), and saw-scaled viper (genus Echis) — are responsible for the majority of snakebite fatalities. Venom from these four species is used in the production of polyvalent antivenoms (PVAs) in India.
- However, this approach leaves other venomous species, such as the king cobra, monocled cobra, banded krait, Sochurek’s saw-scaled viper, hump-nosed viper, and various pit vipers, uncovered by existing PVAs. This gap means that victims bitten by these snakes often receive ineffective treatment, leading to severe or even fatal outcomes.
- A pivotal 2020 study conducted by researchers from Canada, India, and the U.K. estimated that between 2001 and 2014, India experienced a staggering 1.2 million deaths and three times as many cases of permanent disability due to snakebites. The study also revealed that one in 250 Indians is at risk of succumbing to a snakebite before turning 70.
- These alarming statistics highlight a complex interplay of ecological, social, and systemic issues. Rural communities, particularly agricultural workers, face the greatest risk, especially during the monsoon season when snake activity increases.
- Additionally, rapid and often unregulated urbanization, inadequate waste management, and urban flooding have heightened human-snake encounters, leaving even urban populations increasingly vulnerable
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Why are antivenoms hard to get?
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5. How are antivenoms are changing?
- Future advancements in antivenom production offer significant promise. Researchers are leveraging recombinant DNA technology to develop lab-engineered, synthetic antivenoms that are free of animal-derived proteins, enhancing both safety and efficacy.
- Additionally, computer-designed proteins are speeding up the development process by enabling researchers to optimize antibodies for specific clinical applications.
- For instance, on January 15, a team of researchers from Denmark, the U.K., and the U.S., led by 2024 Nobel laureate David Baker, successfully utilized Artificial Intelligence (AI) to design synthetic antivenoms.
- These breakthroughs signal the potential for greater effectiveness, wider availability, and a move away from the traditional century-old methods of antivenom production.
- Region-specific antivenoms also represent a promising direction. Research led by Karthik Sunagar at the Indian Institute of Science, Bengaluru, has highlighted the variations in venom composition across species and geographic regions.
- By mapping these toxin profiles, scientists are working toward creating tailored antivenoms for more precise treatments.
- Furthermore, innovations like portable venom-detection kits and rapid diagnostic tools are helping to ensure antivenoms are used more effectively. With sustained investment in research, public awareness, and infrastructure improvements, India can make significant strides in addressing its snakebite crisis, paving the way for a future where tragedies like Mayuri’s become a rarity
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For Prelims: Snakebites, antivenom, non Communicable diseases
For Mains: GS III - Science & Technology
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Source: The Hindu
