Covisheild & Covaxin : How are vaccines made and how do they work?

From the moment vaccines were discovered, they've come to play big roles in medical therapy. Sometimes, their roles are indispensable. Covaxin and Covishield is one of those vaccines which play indispensable roles. They were developed by Bharat Biotech and the serum institute of India respectively, to act against the coronavirus that's responsible for Covid-19.

The discussion on how Covaxin and Covishield are made is incomplete without answering this question:

What exactly are vaccines?

Vaccines are a product that stimulates a person's immune system to develop immunity to a specific disease, protecting the person from that disease. They can be delivered into the body system subcutaneously via needles. Another method is through the nose or mouth by spraying.

How are Covaxin and Covishield made?

Before getting right into it, it's important to know that vaccines are composed of 7 major ingredients:

• Antigens: These are substances that bring about the immune responses in the host organism. In vaccine preparation, the antigen could be the entire organism (pathogen) or simply a part of it - the coat, sugar, etc. 
• Surfactants: Keeps the constituents from coming together
• Preservatives: The antigens can be degraded easily, once exposed to air. The preservatives stop this from happening when the vial is opened.
• Diluents: For a vaccine to work perfectly and not harm the body, a specific concentration is needed. The diluent gives the vaccine the concentration that's required for it to act. It's mostly sterile water.
• Residuals: Residuals are not added on purpose to vaccines. Instead, they are remnants of the ingredients used to make vaccines.
• Stabilizer: These prevent chemical reactions from occuring between the components of the vaccines. It could be Sugars, amino acids, proteins, etc.
• Adjuvants: Adjuvants boost the immune response provided by the vaccine. It does this in two ways: keeping the vaccine at the injection site for a longer period or inducing the production of immune cells. Aluminum salts are mostly used. The use of adjuvants reduces the dose of vaccine delivered into the body.

The respective composition of covaxin and covishield, are listed below:

Covaxin: Covaxin is composed of coronaviruses that have been killed. Hence, the body is stimulated to produce antibodies that act against coronavirus.

Covishield: Covishield is made from a virus responsible for the common cold, (adenovirus), and has been genetically engineered from our close relatives - chimpanzees. This generates an immune response in the body.

Before production vaccines pass through several steps and phases which are put in place to ensure the safety of the vaccine before it is used. Due to the unique situation that demands the urgent development of a vaccine, scientists have had to stay hours developing these vaccines. Also, the scientists worked for hand in hand with relevant regulatory bodies, responsible for ensuring the vaccine's safety. Hence, the time between the preclinical and clinical trials was eliminated without compromising safety protocols or the safety of the vaccines.

How do Covishield and Covaxin vaccines work?

The operating principle of vaccines differs. Each approach has its merits and demerits. They include

• Inactivation of the virus
• Weakening the virus
• Use part of the virus
• Using the genetic code of a part of the virus. Vaccine development has been the reason for hope in the ongoing Covid-19 pandemic. Hence, no matter the platform on which they are developed — all serve a common purpose: to protect the vaccinated individual from the deadly disease. So make sure you get yourself vaccinated. 

To learn more about the COVID19 vaccines and to find out where you can get vaccinated, use Zyephr!