If an antivenom has undergone risk-benefit assessment involving thorough evaluation of relevant data, laboratory testing of samples and WHO inspection of relevant manufacturing sites — and the outcome is positive — then it may be included in the WHO List of Recommended Antivenoms.

Risk-benefit assessment is a limited process for antivenoms that evaluates and compares the risk of using products that may not be completely GMP-compliant, or for which formal evidence of effectiveness is lacking, against available evidence of safety, preclinical efficacy, and clinical effectiveness from a variety of sources. Moreover, it includes a critical evaluation of current GMP-compliance.

The risk-benefit assessment process aims to provide an informed evaluation of whether the potential benefits to patients of using specific products outweigh any identified risks and weaknesses.

WHO uses this information to make appropriate recommendations for procurement to countries and other product users, and to assist manufacturers to identify those areas which need improvement and strengthening before more formal processes such as prequalification can be implemented.

WHO cannot represent that the listed antivenoms and manufacturing sites will continue to meet the aforesaid standards and/or operational specifications. WHO may suspend or remove an antivenom from the list based on information that may subsequently become available to it (including information regarding failure of the responsible NRA to exercise independent and appropriate regulatory oversight).

The list is not an exhaustive list of antivenoms used to treat snakebite envenoming. Products listed are for use in treating envenoming by particular species of snakes in specific regions of the world. It reflects those antivenoms which have been submitted to WHO for evaluation by manufacturers responding to a call for applications, and which — at the time of evaluation and site inspection — have been found to meet the criteria for a positive risk-benefit assessment.

Antivenoms included in the list are — subject to the terms of the risk-benefit assessment procedure — acceptable, in principle, for procurement by UN agencies. Inclusion in the list does not imply any approval by WHO of the antivenoms and manufacturing sites in question. (This is the prerogative of the NRAs.).

This list may not be used by manufacturers and suppliers for commercial or promotional purposes.

Any UN organization intending to use the list of prequalified vaccines for procurement should ensure that only vaccines from the manufacturers mentioned in this list are supplied to it.

Procurement agencies using this list for procurement should perform other aspects of qualification prior to purchasing, such as ensuring financial stability and standing of the supplier, ability to supply the required quantities, and other related aspects, including the registration status or other authorization of the antivenoms they wish to procure.

Outcomes of risk-benefit assessment

Where there is a positive risk-benefit assessment for an antivenom, WHO will list details of the product and the recommendation notice on this website. WHO Public Assessment Reports (WHOPARs) and WHO Public Inspection Reports (WHOPIRs) will also be published as they become available.

Where a final decision has been made to terminate an assessment or withhold any positive recommendation the name of the product and the manufacturer will be listed below. Termination means that WHO stopped the risk-benefit assessment because of information that would not have enabled a positive outcome to be reached. Where a positive recommendation is withheld, this means that the risk-benefit assessment determined that risks associated with use of a product may be greater than any potential benefits.

Procurement agencies should be very cautious when considering the use of any product for which WHO has either terminated an assessment or withheld any recommendation.