Sarat Chandra IAS Academy

Booster Shots for Covid 19 Vaccines

Booster Shots for Covid 19 Vaccines

#GS1 #Health related issues #GS3 #Disaster management

Context: Recently, Many Vaccine Candidates have announced that they would seek regulatory authorization for a third booster dose of their Covid-19 vaccine (BNT162b2).

What are Booster Shots?

  • A booster is a means of strengthening one’s immune system against a particular pathogen.
  • It may be exactly the same original vaccine; in which case its goal is to increase the magnitude of protection by producing more antibodies.
    • The vaccine contains weakened forms of the disease-causing virus or bacteria, or it may be made of an altered genetic “blueprint” for the germ that can make one sick.
    • The shot triggers one’s immune system to attack the foreign organism, like it would if you actually got the disease. This helps your immune system remember the disease-causing germ.
  • Scientists can tweak what goes into the booster if they are aiming to protect people from a new variant — a version of the virus that’s mutated significantly from the original version people were vaccinated against.
  • Booster shot gives the memory cells the crucial signal to re-engage when the virus attacks. This can be useful whether the booster contains the original vaccine or something different.
    • If it contains the original one, it’ll amplify the signal, increasing the number of antibodies produced and
    • If it contains a tweaked recipe, it will train the cells to recognise new features of the virus and produce antibodies, should one be exposed to a newer variant.
  • These shots are only for the fully-vaccinated.


  • This development comes amid the global spread of highly transmissible Delta strain of Covid-19 and emergence of new variants like Lambda.
  • Research shows that the Delta mutation is powerful enough to make even mRNA shots from BioNTech SE and Moderna less effective, bringing down protection to below 90%. The effectiveness of AstraZeneca’s viral vector vaccine against symptomatic infections caused by the variant was lower at 60%.
  • These boosters will be particularly helpful for the elderly and immunocompromised people whose bodies were unable to mount a robust protection against the virus following the first two shots.
  • Secondly, if there are studies showing that a new variant can sneak past the antibodies created by a specific vaccine, the need of a tweaked booster shot arises then.
  • Initial data from Pfizer’s booster study demonstrates that the added dose was eliciting 5-10-fold higher antibody response.
  • However, the Centres for Disease Control and Prevention hasn’t offered any recommendations on this and has issued a statement saying Americans don’t need a booster shot yet.


  • Booster shots are yet to get a nod from the World Health Organisation (WHO).
  • In fact, the WHO has expressed caution in encouraging third doses.
  • Such a recommendation is unnecessary and premature given the paucity of data on booster shots and the fact that high-risk individuals in much of the world still haven’t been fully vaccinated.

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