Articles Daily Current Affairs Schemes- Policies- Initiatives

How does Sputnik V Vaccine work?

Context: Sputnik V Vaccine, the vaccine against Covid-19 developed by Russia, has been cleared for emergency use by the Drugs Controller General of India, the country’s drug regulator.

  • It is now the third coronavirus vaccine to get emergency use approval, after Covishield (Serum Institute of India) and Covaxin (Bharat Biotech).

Analysis

  • The Sputnik V vaccine uses two different viruses that cause the common cold (adenovirus) in humans.
  • The adenoviruses are weakened so they cannot replicate in humans and cannot cause disease.
  • They are also modified so that the vaccine delivers a code for making the coronavirus spike protein.
  • This aims to ensure that when the real virus tries to infect the body, it can mount an immune response in the form of antibodies.
  • Sputnik uses a different vector for each of the two shots in a course of vaccination.
  • Using a different adenovirus vector may help create a more powerful immune response (compared with using the same vector twice), as it minimizes the risk of the immune system developing resistance to the initial vector.

What is a vector-based vaccine?

  • Viral vector-based vaccines differ from most conventional vaccines in that they don’t actually contain antigens, but rather use the body’s own cells to produce them.
  • They do this by using a modified virus (the vector) to deliver genetic code for antigen, in the case of COVID-19 spike proteins found on the surface of the virus, into human cells.
  • By infecting cells and instructing them to make large amounts of antigen, which then trigger an immune response, the vaccine mimics what happens during natural infection with certain pathogens – especially viruses. This has the advantage of triggering a strong cellular immune response.

What are antigens?

  • Antigens are proteins which our immune system can recognize.
  • Majority of antigens are proteins but some are carbohydrates, lipids, and nucleic acids.
  • Any antigen that is ‘foreign to our immune system is destroyed by an antibody.

What are antibodies?

  • Antibodies are attack molecules our immune system makes to protect ourselves against foreign things such as bacteria and viruses.
  • Antibodies circulate throughout the body until they find and attach to the antigen.
  • Once attached, they can force other parts of the immune system to destroy the cells containing the antigen.
  • Antibodies can also be formed in response to different blood groups.
  • Everyone is born with some antibodies.

What are epitopes?

  • Whenever we refer a pathogen (disease causing organisms), we may think the entire microbe is responsible for the disease.
  • But the fact is these organisms possess numerous sites called as epitopes that are recognized by antibodies or receptors on the cells in the immune system.

Click here to get Free Study Materials for UPSC IAS 2021/22
Click here to follow our latest updates
Click here to join our Civil Servies Test Series