The third shot of the COVID vaccine, also known as the booster shot has been in talks due to the upcoming variants and their risks. This article throws light on the Lancet study clarifying if the general population requires the booster or would the two COVID vaccine shots be enough.

Boosters designed especially to match possible future variations may be more effective and last longer than boosters using currently available vaccines. An expert assessment by a multinational panel of experts, including those from the World Health Organisation (WHO) and the US Food and Drug Administration (FDA), determined that vaccination effectiveness against severe COVID-19 is so high that booster doses for the general population are not suitable at this point in the pandemic.

The study

The study, which was published on 13th September in the issue of The Lancet, summarises the current data from randomised controlled trials and observational research published in peer-reviewed journals and preprint sites.

Lead author Dr Ana-Maria Henao-Restrepo of the WHO stated,

"Taken together, the existing data does not support a significant decline in protection against severe illness, which is the main aim of vaccination. If made accessible to individuals at high risk of severe illness, the limited quantity of these vaccinations will save the majority of lives. Even if any advantage is derived through boosting, it will be little in comparison to the benefits of giving initial protection to the unvaccinated. If vaccinations are used where they are most effective, they have the potential to accelerate the end of the pandemic by impeding further development of variants."

Findings from the study

Observational studies consistently demonstrate that vaccinations are extremely effective against severe illness, including those caused by all major viral varieties. By averaging the findings of observational studies, immunisation was 95 per cent effective against severe illness caused by both the Delta and Alpha variations, and more than 80 per cent effective against any infection caused by both variants.

The authors of the study highlighted that even if antibody levels in vaccinated people decline over time, this does not always imply that vaccinations will lose their effectiveness against severe illness. This may be because protection against severe illness is provided not just by antibody responses, which may be transient in certain vaccinations, but also by memory responses and cell-mediated immunity, which are usually more persistent.

Even if new variations resistant to existing vaccinations develop, they are more likely to originate from strains that have already spread extensively. As a result, boosters designed, especially to match possible future variations may be more effective and last longer than boosters using currently available vaccinations. A similar approach is employed for influenza vaccinations, in which each yearly vaccine is developed using the most recent data on circulating strains, increasing the chance that the vaccine will stay effective even if the virus evolves further.

According to co-author Dr Soumya Swaminathan, WHO's Chief Scientist,

“Currently existing vaccinations are safe, effective, and save lives. While the notion of further decreasing COVID-19 instances via vaccination enhancement is attractive, any choice should be evidence-based and weigh the advantages and dangers to individuals and society. These high-stakes choices should be founded on solid data and worldwide scientific debate."

Has any country been using COVID booster?

Several nations, notably Israel, France, and Germany, have already begun rolling out third doses. Others, notably the United Kingdom and the United States, intend to follow suit in September.

Previously, the World Health Organisation recommended delaying COVID-19 vaccine booster doses until the end of September. The Director-General Dr Adhanom Ghebreyesus asked for an extension until at least the end of the year to help countries close the vaccine gap.

Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

The author is a practising super specialist from New Delhi.