The Omicron variant of the Covid-19 virus has taken the world by storm and is causing peak levels of Covid-19 infections akin to the first and second wave. There are questions arising on the efficacy of current Covid-19 vaccines on the Omicron variant, and studies are ongoing on the subject. The effects of the Omicron variant are said to be milder in vaccinated individuals and can be more severe in those who are yet unvaccinated. But the goal of vaccine makers is to minimise a Covid-19 infection altogether, rather than be satisfied that a vaccine is preventing severe disease.

At the moment, a third booster dose of the Covid-19 vaccine is said to be the best defence against the Omicron variant, at least until a modified vaccine that provides better protection is available.

Let us look at a few studies being conducted to find out the efficacy of current vaccines against Omicron.

AstraZeneca Booster Provides Immunity Against Omicron

A recent study on the AstraZeneca Covid-19 vaccine, whose Indian manufactured version is known as Covishield, showed that just two doses of the vaccine are insufficient in providing immunity against the Omicron variant.

Although two doses may prevent severe disease and hospitalisation, the study showed that a third booster shot provided significantly more protection against the new variant. After a third booster dose of the AstraZeneca vaccine, the levels of neutralising antibodies were higher than those that were vaccinated with just two doses.

A booster shot also resulted in more antibodies than those who had previously contracted the disease and recovered from it. The Indian government has already started providing booster shots of Covershield for healthcare workers and for persons aged above 60 years. If you’re eligible, get your precaution dose as soon as possible since currently, that is the best protection against the Omicron variant.


The Pfizer-BioNTech vaccine, which is predominantly being used in the US, has also conducted a study for efficacy against Omicron that indicates that three doses of the vaccine are capable of neutralising the Omicron variant effectively. The antibody titres from three doses of the Pfizer vaccine were found to be 25 times that of sera with just two doses. Thus, this preliminary study clearly points towards a third dose being effective against the Omicron variant. Pfizer also believes that vaccinated individuals would still be protected from severe forms of the disease. The third dose will provide more robust protection against the virus since it induces higher antibodies.

WHO says the Covid-19 vaccines may need to be updated

Even though recent studies suggest that the third dose of vaccines is sufficient for protection against the Omicron variant, the World Health Organisation (WHO) technical body said that the current vaccines might need to be updated for better protection. The WHO body emphasised a change in vaccine composition for a more solid defence. They said that the Covid-19 vaccine needed to elicit an immune response that was broader, stronger, and long-lasting in order to protect against Omicron and other future variants without the need for further booster doses. “A vaccination strategy based on repeated booster doses of the original vaccine composition is unlikely to be appropriate or sustainable.”, the WHO body said.


Having read through the recent studies on the efficacy of current vaccines against Omicron, one can conclusively say that even though two doses of vaccine may prevent severe disease, they’re simply not enough to provide comprehensive protection against Omicron. A third or booster dose is a must for effective neutralisation against this rapidly spreading virus.

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