Your definitive guide to Covid-19 | Does vaccine booster protect against Omicron?

India has joined a long list of nations administering Covid-19 vaccine's booster doses. In an address to the nation in December 2021, Prime Minister Narendra Modi specified that the 'precautionary' third dose of the vaccines would be reserved for healthcare and frontline workers. Those aged above 60 years with comorbidities are also eligible for a booster shot based on their doctor's advice. Coinciding with a surge in cases believed to be due to the Omicron variant, many doubts have emerged among the general populace. Here are answers to frequently asked questions on booster shots.

BOOSTER Vs ADDITIONAL DOSES

Booster doses are distinct from additional doses of vaccines. The former are given after protection induced by the original shots begins to wane over time. However, additional vaccines are only given to people who have a compromised immune system, and therefore need help to improve their response to the original shots. These include cancer and HIV patients, among others. India is calling its booster shots a 'precautionary dose'. Reports have quoted experts as saying that these are boosters, rather than additional doses of vaccines.

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BOOSTER EFFICACY

The biggest question in people's minds is whether a booster shot provides protection against hospitalisation, especially if an individual is infected with the Omicron variant. Early studies in the UK have shown that a third dose of the vaccine can provide up to 88% protection against hospitalisation from infection by Omicron. Those with only two shots have up to 72% protection. Researchers said that vaccine efficacy against hospitalisation drops to 52% against Omicron around 6 months after taking the second shot. A report said that over four-fifths of Omicron patients in England's hospitals had not had booster shots.

COUNTRIES GIVING BOOSTERS

As per the World Health Organisation, over 120 countries have started implementing booster or additional vaccine programmes. In the US, apart from fully vaccinated adults, even 16 and 17 year olds can get boosters, albeit only Pfizer-BioNTech. Canada's immunisation advisory committee has recommended mRNA vaccine boosters to those with moderately or severely compromised immune systems, as per a Reuters report. The European CDC has recommended vaccine boosters for all adults, with priority for those aged above 40. England is offering boosters to all adults, 3 months after the second shot.

In South Africa, where Omicron was first detected, boosters of Johnson & Johnson vaccine have been available since Dec 24, as per Reuters. Other African nations like Egypt, Kenya, Morocco, Nigeria, Tunisia, and Zambia also have booster programmes, as per reports.

Closer home, Bangladesh is offering boosters to frontline workers. Other Asian countries like Indonesia, Malaysia, Singapore, Philippines, among others have booster schemes. Significantly, Israel is now offering a fourth dose to the immunocompromised and elderly.

THE CRITICISM

However, even as more and more countries roll out booster programmes, voices of criticism have been rising, led by the World Health Organisation. The international health policy body's chief Dr Tedros Adhanom Ghebreyesus expressed concern about 'blanket booster programmes' worsening vaccine inequity across the world. He pointed out that while well-to-do countries are administering extra doses, poorer countries are yet to reach a significant milestone in primary vaccination. He said that blanket booster schemes would end up prolonging the pandemic, rather than ending it.