Explained: The use of animal serum in making of vaccines
New Delhi, June 18: As India aims to rampup its vaccination drive amid second wave, various conspiracy theories have hit headlines triggering widespread debate among the people. The use of calf serum is one such allegation that has created quite a flutter on social media.
The government responded to the news, saying the social media posts regarding composition of the COVAXIN vaccine, the use of newborn calf serum as misrepresented facts.
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," it said.
"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," it added.
"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, " the government clarified.
Animal serum in vaccines
Use of animal serum is a common norm to those in the vaccine industry, but it has come as a bit of a surprise to the general public. Horses and other animals were used to produce antitoxins in a variety of diseases, such as diphtheria, tetanus, and scarlet fever. It has a history over 100 years.
Remarkably, in India, the Poonawalla family, began breeding horses in 1946, before a debate on use of animal serum sparked the realisation that anti-toxin serum extracted from the animals could be used to make vaccines.
The difference between FBS and NBCS
Fetal bovine serum (FBS) comes from the blood drawn from a bovine fetus via a closed system of collection at the slaughterhouse.
Newborn calf serum (NBCS) is collected from calves typically 20 days old or younger. The calf serum has been seen as a replacement for FBS as it is of a higher quality and is a cost-effective.
Why calf serum
"Cow components are often used simply because cows are very large animals, commonly used for food, and thus much material is available," says the Food and Drug Administration of the United States.
"Animal-derived products used in vaccine manufacture can include amino acids, glycerol, detergents, gelatin, enzymes and blood. Cow milk is a source of amino acids, and sugars such as galactose. Cow tallow derivatives used in vaccine manufacture include glycerol. Gelatin and some amino acids come from cow bones. Cow skeletal muscle is used to prepare broths used in certain complex media," it said.
"Many difficult to grow microorganisms and the cells that are used to propagate viruses require the addition of serum from blood to the growth media," it added.
According to one international manufacturer of these chemicals, Thermo Fisher Scientific, Calf serum used in vaccine production for over 50 years, and it has proven itself as an extremely effective growth supplement.