A booster dose against COVID-19 increases the amount of circulating antibodies and is shown to increase protection from symptomatic infection with Omicron, scientists have said, underlining that boosters can be the simplest step forward, especially for the immunosuppressed.

Reacting to the statement of UK Health Security Agency (UKHSA) that booster dose of Covishield vaccine effective against Omicron and a third booster dose of COVID-19 vaccine provides 70-75 per cent protection against symptomatic infection from the Omicron variant, the virologists and epidermalogists underlined that booster doses of any vaccine (except live attenuated like oral polio vaccine or OPV, measles) exponentially raises antibody level.

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Eminent virologist Dr Shahid Jameel said a booster shot after two doses increases the amount of circulating antibodies and is shown to increase protection against symptomatic infection with Omicron.

“We don’t know how well two doses continue to protect against severe disease,” he told PTI.

Also read: UK scientists urge more restrictions to fight omicron surge

On what India should do where majority of population is vaccinated with Covishield, the former head of the advisory group to the Indian SARS-COV-2 Genomics Consortia (INASACOG) said it must be ensured that those who got only one dose of Covishield get the second dose in 8-12 weeks instead of 12-16 weeks.

“Carry out lab studies with Omicron to learn how well sera from Indian vaccines of Covaxin and Covishield neutralise the virus. Make a policy on boosters. What vaccines to use? Who should get it? And when?  Make a policy and start vaccinating children starting with adolescents,” he said.

Also read: Omicron wave in England could cause 75,000 deaths by April end: Study

Jameel said in India, four vaccines can be used as boosters: Covaxin in people who got Covishield and vise versa, DNA vaccine ZyCov-D, Covovax protein vaccine from SII and Corbev ax-E protein vaccine from Biological E.

The Health Ministry told the Lok Sabha last week that the National Expert Group on Vaccine Administration for COVID-19 (NEGVAC) and the National Technical Advisory Group on Immunisation (NTAGI) are considering scientific evidence related to justification for booster doses against the coronavirus.