Is cows blood used in vaccines?

The use of bovine serum in vaccine manufacturing has been a long-standing practice; this has been due to its availability, low immunogenicity, reasonable affordability, the ease of collection from animal's blood, high growth factor activity with the added advantages of its ability to stabilize other labile ingredients in a formulation.

Bovine serum or calf serum was previously widely used but has now gradually been replaced due to various ethical concerns arising from animal cruelty to a more animal-free, cost-effective, non-immunogenic substitute like fetal bovine serum (FBS). FBS is harvested postmortem.

Some vaccines which do use some form of cattle-based growth-medium in production currently include vaccines for: mumps, rubella, rotavirus, polio, varicella, typhoid, meningitis, tuberculosis, Hepatitis A as well as the COVID-19 vaccines like COVISHIELD manufactured by the Serum Institute of India (SII), Covovax manufactured by Novavax, Johnson and Johnson vaccine and Sputnik V both developed by the Gamaleya Research Institute of Epidemiology and Microbiology.