Covaxin's final product has no calf serum, Bharat Biotech and govt clarify

Health ministry says this has been used for decades in Polio, Rabies, and Influenza vaccines, is neither used in growth of SARS CoV2 virus nor in the final formulation

The Government on Wednesday clarified that Bharat Biotech’s Covaxin does not contain newborn calf serum at all and that the calf serum is not an ingredient of the final vaccine product. Amid the controversy, Bharat Biotech also clarified that new born calf serum is used in the manufacturing of viral vaccines.

A Health ministry statement explained that the newborn calf serum is used for preparation and growth of vero cells which are used in production of vaccines. This technique has been used for decades in Polio, Rabies, and Influenza vaccines.

“It is used for the growth of cells, but neither used in growth of SARS CoV2 virus nor in the final formulation. Covaxin is highly purified to contain only the inactivated virus components by removing all other impurities,” the company said.

These cells are then washed with water, chemicals to make them free of the newborn calf serum. The vero cells are then infected with coronavirus for viral growth and in the process they are completely destroyed.

The virus thereafter is killed or inactivated. The killed virus is then used to make the final vaccine. “In the final vaccine formulation no calf serum is used,” the health ministry said. The clarification was issued after questions were raised in social media posts over the composition of Covaxin and use of newborn calf serum.

It also clarified that different kinds of bovine and other animal serum is a  standard enrichment ingredient used globally for vero cell growth. A senior official in a vaccine manufacturing firm explained, "The blood is collected from the calf within three to ten days of its birth. This is very commonly used to make vaccines. Cattle blood is easier to source than other animals, and hence this is standard practice. For laboratory purposes, mostly such sera are imported.”

Bharat Biotech also clarified that the usage of new born calf serum was 'transparently documented' in several publications in the last nine months. The company had mentioned the same when it published animal trial study documents -which involved trials on hamsters and monkeys; in pre-clinical safety and immunogenicity study reports; in studies on neutralisation of the UK variant, the South Africa variant, the Delta variant among others.