Risk Assessment - Snake antivenom
In the absence of treatment, snakebite envenoming results in high morbidity and mortality with grave socio-economic consequences for victims, families, and communities. Globally WHO estimates that there are between 81,000 and 138,000 snakebite-related deaths occur each year, and that long-term consequences for survivors (including amputation, other disabilities, and post-traumatic stress) affect at least 400,000 more*.
Despite this high burden, snake antivenoms are often unavailable to those in need, hampering effective treatment. When they are available, they may have been prepared from poor quality snake venoms that are not regionally representative or have been poorly designed and manufactured and have limited efficacy.
In some countries that use these products to address their significant snakebite problems there may be a lack regulatory capacity to assess the quality and specificity of the antivenom preparations manufactured in their country or coming into their countries.
In such circumstances where the quality of products may not have been reliably or completely verified the confidence of health care providers and patients with respect to antivenom products has declined, leading to loss of demand despite abundant need, and an increase in morbidity and mortality.
Yet if sufficient, quality-assured antivenoms were available, most of the deaths and the harm caused by snake bites could be prevented. Antivenoms are therefore included in the WHO Essential Medicines List. They are blood-derived, usually consist of immunoglobulin preparations, purified from animal-derived hyperimmune plasma, and enzymatically digested into antibody fragments.
In 2018 the World Health Assembly adopted resolution 71.5 (2018: Addressing the burden of snakebite envenoming) which calls on WHO to ensure the quality and safety of snake antivenoms and this work directly addresses that request. WHO has developed a risk-benefit assessment procedure for snake antivenoms, to assist interested WHO Member States, United Nations’ procurement agencies, international organizations and other stakeholders in determining the acceptability of using specific snake antivenom products, based on an evaluation of an essential set of available quality, safety, efficacy, and performance data.
Furthermore, it provides manufacturers with independent product analysis, evaluation of Good Manufacturing Practices (GMP) and potential product recommendation. Overall, the risk-benefit assessment process is aimed at improving the availability of safe, effective antivenom immunoglobulin products to all who need them.
* World Health Organization. Snakebite envenoming: A strategy for prevention and control. 2019. https://apps.who.int/iris/rest/bitstreams/1230920/retrieve