Snake Bite Envenomation
AAHI’s adjuvant formulations may enable more sustainable and humane production of snake antivenom, a treatment for snakebite envenomings that saves lives by neutralizing venom toxins in a victim’s blood and tissues. Such antivenom is produced from antibodies from the blood of large mammals such as horses or sheep who are immunized by injection with small amounts of snake venom. Administering AAHI’s immune-enhancing adjuvant formulations with snake venom stimulates more efficient production of such antibodies, while reducing local reactogenicity at the site of injection compared to traditionally used formulations. Thus, it is anticipated that this approach will enable more doses of snake antivenom to be inexpensively and sustainably produced, to address urgent global unmet needs. AAHI is working with its partners, including the Instituto Clodomiro Picado of University of Costa Rica, to support and advance research and development leading to global equitable access to life-saving snake antivenom.
Untreated snakebite envenomings can result in death, amputations, neurological damage, organ failure, and/or permanent disability. In 2019, these envenomings claimed 138,000 human lives and permanently disabled 400,000 people, costing millions of years of health and productivity. The WHO declared envenoming a top priority neglected tropical disease in 2017, and again elevated the urgency of the snakebite health crisis in 2019, stating a new sustainable development goal to reduce the number of snakebite deaths and disabilities by 50% before 2030. Despite recognition of this urgent need, however, there is still a global shortage of snake antivenom.
The densest populations of venomous snakes, particularly vipers (rattlesnakes, cottonmouths, copperheads, lancehead vipers, Russell’s vipers, saw scale vipers) and elapids (black mambas, cobras, krait coral reef snakes), are found in Australia and tropical regions of developing nations in Asia, Latin America, and sub-Saharan Africa. In places such as the river valleys of the Democratic Republic of the Congo, the Amazon rainforest of Brazil, and the jungles of India, snakebite is so common that it is considered an “occupational disease” for farmers, fishermen, and cattle herders. Once a victim is bitten, immediate treatment is required to mitigate or avoid devastating health consequences. Availability and immediacy of treatment, however, is extremely challenging in rural and remote communities with undeveloped healthcare infrastructure.
‘Snakebite is the most important tropical disease you’ve never heard of’
– Kofi Annan, United Nations secretary general
Antivenom works by stopping venom toxins from spreading and damaging key physiological functions; it cannot undo damage that a victim may already have suffered. It is absolutely critical that antivenom be administered to a snakebite victim as soon as possible. In the river valleys, agricultural fields and jungles where snakebite is most common, however, it can take hours, even days, to bike, canoe, or be carried by foot to the nearest medical center. In rural communities of South Asia, South America, and sub-Saharan Africa, where 95% of deaths by snake bite occur, there is no guarantee even that the nearest medical center will have staff trained to administer antivenom or, for that matter, any antivenom in stock.
Antivenom for venomous snake species native to the areas of the world most burdened by deaths and injuries due to snakebite (South Asia, South America, Africa) is often unavailable or in limited supply. There is urgent unmet need for a reliable supply of affordable antivenom.
Antivenom is typically specific to snake species, and there are over 600 species of venomous snakes. While several countries have established antivenom producers, they are largely focused on local venomous snakes, scorpions, and spiders, while there is limited antivenom production for regions of high snakebite incidence, particularly in sub-Saharan Africa and parts of Asia. Other antivenom products available on the commercial market are either too expensive for true accessibility, or have been withdrawn from the market, for lack of profitability.
Traditional production of antivenom takes a lot of money, time, and snakes, requiring:
Step 1. Capturing and “milking” a venomous snake to extract venom from its fangs into a bottle;
Step 2. Immunizing a horse by injecting it with small amounts of the snake venom, triggering an immune response that results in the production of antibodies;
Step 3. Extracting, concentrating, and purifying antibodies from the horse’s blood to make an antibody-laden serum (antivenom) that can be injected into humans.
Administering AAHI’s adjuvant formulations with small amounts of venom in Step 2 amplifies production of antibodies, which is anticipated to result in a corresponding reduction in effort and cost per dose of antivenom.
AAHI scientists are working with the University of Costa Rica, which has an antivenom manufacturing facility that conforms to GMP (‘Good Manufacturing Practices’ promulgated by biologic and pharmaceutical regulatory agencies), to research and develop the use of adjuvant formulations for horse immunization with the goal of enabling more efficient, sustainable, and cost-effective production of antivenom.
AAHI and its partners are committed to continued collaboration, to address global needs for life-saving antivenom against venomous snake bites. AAHI’s adjuvant formulations provide a practical way to increase production and reduce costs, making antivenom more equitably available and accessible.