Syllabus section: Science and technology

Why in News?

The Drug Controller General of India recently announced that it has authorised two COVID-19 vaccines for restricted Emergency Use in India

What is COVAXIN?

The COVAXIN is the COVID-19 vaccine developed by Bharat Biotech and ICMR (Indian council of Medical Research). It was the first indigenous COVID-19 vaccine to be developed in the country.

Once the vaccine is injected into a human, it has no potential to infect or replicate, since it is a killed virus. It just serves to the immune system as a dead virus and mounts an antibody response towards the virus

What is COVISHIELD?

The COVISHIELD vaccine was developed by Oxford University and Astra Zeneca, the pharmaceutical company

How the vaccines have been developed?

Covishield uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.

Covaxin is an inactivated vaccine. An inactivated vaccine is one which is developed by inactivating (killing) the live microorganisms that cause the disease. This destroys the pathogen’s ability to replicate, but keeps it intact so that the immune system can still recognise it and produce an immune response. There are many inactivated vaccines against Hepatitis A, Influenza, Polio, Rabies, which offer “excellent protection