DNA Explainer: Do you need booster dose after getting fully vaccinated? Know what is India's stand

Even as the world is busy inoculating its population against the COVID-19 virus, questions arise as to whether a booster dose of the vaccine is needed to be administered to those who have already taken both their vaccine doses.

Recently, the US Centers for Disease Control and Prevention (CDC) published three new studies which say protection offered by Pfizer and Moderna vaccines against SARS-CoV-2 will fade away eventually.

This has led to a debate among experts about the need for booster shots for everyone eventually. The studies were published just about a week after the Food and Drug Administration (FDA) authorised booster shots.

As per the rule, a third shot of the vaccine would be administered for transplant patients and people with weakened immune systems like diabetes and cancer patients for better protection from variants of COVID-19.

However, this decision has not gone down too well with the poor and developing countries. The Africa director for the WHO said Thursday, that some richer countries hoard vaccines and make a mockery of vaccine equity.

African health officials along with Africa Centers for Disease Control and Prevention warned that less than 2% of the population on the African continent of 1.3 billion people is fully vaccinated against COVID-19.

Not just the US, countries like Israel, Germany, and France have already laid out plans to roll out the administration of booster shots. The third shot will be available from September 20 in the US as infections rise.

The UK government is also preparing to offer millions of vulnerable Britons, who have received two doses of the COVID-19 vaccine, a booster jab from September.

The WHO earlier this week said that current data do not indicate that COVID-19 booster shots are needed. It added that the most vulnerable people worldwide should be fully vaccinated before rich countries deploy a top-up.

India's stand on booster dose

All India Institute of Medical Science (AIIMS) Director Dr Randeep Guleria said that India does not have enough data right now on the need for a third COVID-19 vaccine shot to increase protection.

More information is likely to be available by early next year, AIIMS Director Dr Randeep Guleria said today. Dr Guleria said the data in India does not indicate that boosters are needed at present.

Even for the elderly and high-risk groups, India does not have enough data. "We really need to have data that gives us an idea of the protection levels the vaccines provide," he said.

The AIIMS Director further claimed that the UK had a huge surge in COVID-19 cases, but they did not see an increase in hospitalisation despite the fact no booster shots were given.

What studies suggest

A study conducted between May 3 and July 25 in the US found that the vaccine effectiveness against hospitalisations amongst all age groups in New York remained relatively stable.

However, the study revealed that the overall vaccine effectiveness against infection for all age groups of adults in New York was reduced from 91.7% to 79.8%.

One reason for the lowered effectiveness of the COVID-19 vaccines in the US could be the increased viral load associated with the Delta variant of the coronavirus.

Another study was conducted in the US between March and July 2021, on 1,129 COVID-19 patients who received two doses of one of the mRNA vaccines.

It was observed from the results of the study that there was no decline in vaccine effectiveness against the COVID-19 hospitalisation even after six months.

This study found that the vaccine effectiveness was 86% at 2-12 weeks after vaccination and 84% at 13-24 weeks. Vaccine effectiveness was sustained among groups at severe risk.

Protection against severe COVID-19 resulting in hospitalisation was sustained 24 weeks after vaccination with mRNA COVID-19 vaccines, the study found.

Yet another study said that two doses of mRNA vaccines were 74.7% effective against infection among nursing home residents between March to May this year.

This study says that during June-July, when the Delta variant was predominant, the COVID-19 vaccine effectiveness declined to 53.1%.

An additional dose of the vaccine might be considered for nursing home and long-term care facility residents to optimise a protective immune response, the study said.