Snake antivenom immunoglobulins (antivenoms) are the only specific treatment for snakebite envenoming. Antivenoms have been used for more than 125 years to treat snakebites, and when products are well-designed and of good quality they can prevent or reverse most of the effects of snakebite envenoming and play a crucial role in minimizing mortality and morbidity.

Snake antivenoms contain antibodies against one or more specific venoms. They are manufactured by fractionating plasma collected from animals (typically horses or sheep) that have been immunized against relevant venoms and that as a result develop neutralizing antibodies. The plasma is pooled in batches of tens to hundreds of litres and processed to extract the active immunoglobulin fraction, which is then further purified and stabilized to become antivenom.

These preparations are included in the WHO List of Essential Medicines and should be part of any primary health care package where snakebites occur.

Following a broad consultative process that included endorsement by the WHO Expert Committee on Biological Standardization (ECBS), WHO published Guidelines for the Production, Control and Regulation of Snake Antivenom Immunoglobulins in 2010 covering all steps in the production and control of both venoms and antivenoms.

This document published in the WHO Technical Report Series (TRS) is an essential guide for national control authorities and manufacturers to improve worldwide production of quality, safe and effective antivenoms.

The most recent revision of these guidelines was endorsed by ECBS in 2016 and published by WHO in the TRS in 2017.

A knowledge of which species of venomous snakes present the greatest risks to human populations in any region or country is essential to addressing snake bite problems. The WHO antivenom guidelines also contain an Appendix which lists the worldwide distribution of venomous snakes clinically relevant for the production of venoms and antivenoms.  Furthermore, A WHO global database, including maps and image library, has been created to facilitate the geographical representation of the venomous snakes included in the Appendix. This work has been done to facilitate decision making related to regulating, manufacturing and procurement of antivenoms, to help health care workers in their clinical management of snake bite envenomings, and to support prevention initiatives.