Experts say that it is important to receive the second dose of the vaccine as scheduled.

A man receives the first dose of COVID-19 vaccine from a health workerImage for representation
Coronavirus COVID-19 Vaccine Tuesday, March 09, 2021 - 13:50

The cumulative number of COVID-19 vaccine doses administered in the country has crossed 2.26 crore with close to 17 lakh jabs being given on Monday alone, the Union Health Ministry said. With the second phase of vaccine rollout underway in India for those aged over 60, and those over 45 years of age with comorbidities, experts have urged people who received the first dose of the vaccine to exercise caution, adding that it was important to receive their second dose as scheduled.

"After you take the first dose, it takes about two weeks for the immune response to come to its peak level, but then it goes down fairly quickly over the next few weeks. That's why you need a second dose, which is a booster dose," explains Dr Shahid Jameel, a well-known virologist and the Director of the Trivedi School of Biosciences at Ashoka University.

"When you get the booster dose, then the immune response rises very rapidly to reach a peak within a week's time and this response is more long-lasting. So, the first shot gives you a transient response which peaks in two weeks but doesn't last for long. Only after the second shot, you get a response which is long-lasting," he adds.

On Monday, the fifty-second day of the nationwide COVID-19 vaccination drive, 14.30 lakh beneficiaries were vaccinated for their first dose and 2.65 lakh healthcare workers and frontline workers received their second dose of the vaccine. Of the 14.30 lakh beneficiaries who got the first dose, 10.33 lakh beneficiaries were aged over 60, and 1.78 lakh were aged between 45-60 with specified comorbidities, the government said.

"How long-lasting is the response after the second dose? We don't know yet because long-term studies have not been done. Therefore, it is important to take all precautions and wear masks after the first dose because you really don't know if you're protected," Dr Shahid says.

"All vaccines have been tested for their efficacy against disease. They have not been tested for efficacy against infection. So even after two doses, you may still get infected. It's just that if you had the propensity to have severe disease, you'll have mild or asymptomatic disease, but you can still transmit the virus to others. So even after the second dose, precaution should be taken," he further explains.

In countries like the US, health experts have debated on whether to prioritise giving more people the first shot or making sure that the second shots are given in time to those who have already received the first dose.

Some experts had argued that prioritising more first doses would set the country on a better path to tackling the virus, but Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases, contended that the science was not yet clear on the issue and that any research could take time to come to a conclusion.

“What we have right now, and what we must go with, is the scientific data that we’ve accumulated. And it’s really solid. You can do both, you can get as many people in their first dose at the same time as adhering, within reason, to the timetable of the second dose. It would be great to have the study, but I don’t think we could do it in time,” Fauci had told reporters.

Either way, the science is clear that even after the second dose, immunity against contracting the virus is not completely guaranteed, experts say, urging people to continue wearing masks and take other precautions.

With PTI inputs

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