When it comes to getting a vaccine to protect yourself against a disease like COVID-19, booster shots can be a normal part of the vaccination process.
A coronavirus (COVID-19) booster vaccine dose helps improve the protection you have from your first 2 doses of the vaccine. It helps give you longer-term protection against getting seriously ill from COVID-19.
Booster shots are administered to remind the body’s immune system about the virus it needs to defend against. This improves or gives the immune system a boost.
Why is a third/ booster dose given?
A COVID-19 booster is given when a person has completed their vaccine series, and protection against the virus has decreased over time. For eg. if you receive the Covishield booster, you will receive half of the original Covishield dose.
Need for Booster shot?
Although COVID-19 vaccination remains effective in preventing severe disease, recent data suggest vaccination becomes less effective over time, especially in people aged 65 and older and at preventing infection or milder illness with symptoms.
The recent emergence of the Omicron variant (B.1.1.529) further emphasizes the importance of vaccination, boosters, and prevention efforts needed to protect against COVID-19. Early data from South Africa suggest increased transmissibility of the Omicron variant and the potential for immune evasion.
Emerging evidence also shows that among healthcare and other frontline workers, vaccine effectiveness against COVID-19 infections is also decreasing over time.
This lower effectiveness is likely due to the combination of decreasing protection as time passes since getting vaccinated, as well as the greater infectiousness of the Delta variant.
Data from clinical trials showed that a booster shot increased the immune response in trial participants who finished a Pfizer-BioNTech or Moderna primary series 6 months earlier or who received a J&J/Janssen single-dose vaccine 2 months earlier. With an increased immune response, people should have improved protection against COVID-19, including the Delta variant. For Pfizer-BioNTech and J&J/Janssen, clinical trials also showed that a booster shot helped prevent COVID-19 with symptoms.
What about India's stand on booster dose?
Today, the Indian SARS-CoV-2 Genetics Consortium or the INSACOG has said that a booster vaccine dose for people above 40 years of age 'may be considered' amid the rising threat of new Covid variant Omicron.
INSACOG in its latest bulletin said, "Vaccination of all remaining unvaccinated at-risk people and consideration of a booster dose for those 40 years of age and over, first targeting the most high-risk / high-exposure may be considered, since low levels of neutralising antibodies from the current vaccines are unlikely to be sufficient to neutralise Omicron, although risk of severe disease is still likely to be reduced."
The National Technical Advisory Group on Immunisation (NTAGI), had said last month that a policy on the booster and additional doses of the vaccine could be expected in two weeks.