Covaxin is ‘highly purified’ says Bharat Biotech

Covaxin is ‘highly purified’ says Bharat Biotech

Subject: Science & tech

Context: The Union Health Ministry on Wednesday refuted some social media posts on the composition of Covaxin, where it has been suggested that it contains newborn calf serum.

Concept:

• It said that newborn calf serum was used only for the preparation/growth of vero cells. The final vaccine did not contain newborn calf serum, it asserted.
• Vero cells were washed with water and chemicals (also technically known as buffer) many times to make them free from newborn calf serum.
• Thereafter, they were infected with coronavirus for viral growth. Thereafter, the grown virus was also killed (inactivated).
• This killed virus was then used to make the final vaccine and in the final vaccine formulation, no calf serum was used.

Vero Cell

• Vero cells are lineages of cells used in cell cultures. The Vero lineage was isolated from kidney epithelial cells extracted from an African green monkey.
• Vero cells are used for many purposes, including,

Screening for the toxin of Escherichia coli, first named “Vero toxin”.

As host cells for growing viruses.

• The Vero cell lineage is continuous and aneuploid.
• A continuous cell lineage can be replicated through many cycles of division and not become senescent (i.e. not deteriorates with age).
• Aneuploidy is the characteristic of having an abnormal number of chromosomes.