"The innocuity test (also referred to as the abnormal toxicity test, general safety test or undue toxicity test) was originally developed in the early 1900s to ensure the safe and consistent production of serum products containing phenol-derived preservatives [1]. The test was later expanded to a general safety test to detect possible extraneous toxic contaminants (other than, for example, bacterial endotoxins) in biological products [1]. The principle of the test consists of injecting the product into guinea pigs and/or mice. A batch passes the test if no animal shows any signs of illness, relevant body weight changes, or dies within 7 days...
A number of national regulatory authorities and Pharmacopoeias have already removed, or are working on the removing of the innocuity test from their requirements or pharmacopoeias. In 2015, the U.S.A. Food and Drug Administration (FDA) published in the Federal Register their intent to delete the innocuity (general safety) test"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7391003/

WHO reports on meetings of expert committees and study groups Report by the Director-General
BIOLOGICAL STANDARDIZATION
Sixty-ninth report of the Expert Committee on Biological Standardization

Spanish version

"11. El Comité de Expertos recomendó que, a partir de ahora, y con efectos inmediatos, todos los documentos futuros de la OMS sobre vacunas y otros productos biológicos que se publiquen en la Serie de Informes Técnicos (incluidas las recomendaciones, las directrices y los manuales de la OMS) no incluyan la recomendación de llevar a cabo la prueba de inocuidad. Se acordó que debe efectuarse una declaración en el informe completo del Comité de Expertos en la que se indique que ya no deben tenerse en cuenta las referencias a dicha prueba que figuren en los documentos de la Serie de Informes Técnicos de la OMS publicados con anterioridad. Esto supone un paso importante hacia la reglamentación basada en la ciencia y la convergencia reglamentaria en todo el mundo"
https://apps.who.int/gb/ebwha/pdf_files/EB145/B145_10-sp.pdf

English version

"11. The Expert Committee recommended that henceforth, with immediate effect, all WHO’s future documents on vaccines and other biologicals published in the Technical Report Series (including WHO’s recommendations, guidelines and manuals) should not include a recommendation for conducting the innocuity test. It was agreed that a statement should be made in the full report of the Expert Committee indicating that the inclusion of this test in previously published WHO Technical Report Series documents should now be disregarded. This represents a significant step towards science-based regulation and regulatory convergence at the global level."
https://apps.who.int/gb/ebwha/pdf_files/EB145/B145_10-en.pdf