The final vaccine product of COVAXIN does not contain newborn calf serum at all!
Facts have been twisted and misrepresented in these posts.
Newborn Calf Serum is used only for preparation/ growth of vero cells. Different kinds of bovine and other animal serum are standard enrichment ingredient used globally for vero cell growth. Vero cells are used to establish cell lines which help in production of vaccines. This technique has been used for decades in Polio, Rabies, and Influenza vaccines.
These vero cells, after the growth, are washed with water, with chemicals (also technically known as buffer), many times to make it free from the newborn calf serum. Thereafter, these vero cells are infected with corona virus for viral growth.
The vero cells are completely destroyed in the process of viral growth. Thereafter this grown virus is also killed (inactivated) and purified. This killed virus is then used to make the final vaccine, and in the final vaccine formulation no calf serum is used.
Hence, the final vaccine (COVAXIN) does not contain newborn calf serum at all and the calf serum is not an ingredient of the final vaccine product.