Question

Covaxin, a vaccine developed by Bharat Biotech for covid-19 is

• A. DNA based vaccine
• B. Protein based Vaccine
• C. Inactivated Virus based vaccine
• D. mRNA based vaccine

Hint:

• Inactivated Vaccines Use killed versions of the pathogen. Cannot cause disease. Often require multiple doses (boosters). Example: Polio (Salk), Flu shot, Covaxin.
• Live-Attenuated Vaccines Use weakened (attenuated) versions of the living pathogen. Strong, long-lasting immune response. Small risk of causing mild illness or reverting to virulence (rare). Example: MMR, Chickenpox, Polio (Sabin).
• Subunit/Recombinant/Polysaccharide/Conjugate Vaccines Use specific pieces of the pathogen (like proteins, sugars). Strong immune response to key antigens. Example: Hepatitis B, Pertussis (acellular), Shingles.
• Toxoid Vaccines Use inactivated toxins produced by bacteria. Example: Tetanus, Diphtheria.

Answer 1

The Correct Option is C

Covaxin (BBV152) is an indigenous COVID-19 vaccine developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR) - National Institute of Virology (NIV). Covaxin is an inactivated virus based vaccine. This type of vaccine uses the killed (inactivated) version of the germ that causes a disease. The process involves: 1. Growing the SARS-CoV-2 virus in cell culture. 2. Chemically inactivating the virus so it can no longer replicate or cause disease. 3. Formulating the inactivated virus (which still contains its antigens, like the spike protein) into a vaccine, often with an adjuvant to enhance the immune response. When administered, the immune system recognizes the antigens on the inactivated virus and mounts an immune response (producing antibodies and T cells) without causing the disease, thus providing protection against future infection. Let's look at other vaccine types: (a) DNA based vaccine: Uses genetically engineered DNA to instruct host cells to produce an antigen (e.g., ZyCoV-D for COVID-19). (b) Protein based Vaccine (Subunit vaccine): Uses specific purified proteins (antigens) from the pathogen, rather than the whole pathogen (e.g., Novavax vaccine (NVX-CoV2373), Hepatitis B vaccine). (d) mRNA based vaccine: Uses messenger RNA (mRNA) encoding a specific antigen. The mRNA is taken up by host cells, which then produce the antigen, triggering an immune response (e.g., Pfizer-BioNTech and Moderna COVID-19 vaccines). Covaxin specifically uses the inactivated whole virion approach. \[ \boxed{\text{Inactivated Virus based vaccine}} \]