Delta variant prevalence similar in vaccinated and unvaccinated groups: ICMR study

The study, however, noted that the proportion of patients progressing to severe illness and mortality was lower in the vaccinated groups.

Moneycontrol News

August 19, 2021 / 09:07 AM IST

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A new study by the Indian Council of Medical Research (ICMR) on people infected with COVID-19 has found that the Delta variant of coronavirus can infect the vaccinated population. The study noted that the prevalence of B.1.617.2 (Delta variant) "was not different between the vaccinated and unvaccinated groups."

"B.1.617.2, or the Delta variant of covid causing Sars Cov2 was the dominant circulating strain and one of the primary drivers for the country's covid second wave," the study, approved by the ICMR-National Institute of Epidemiology, Chennai, said, as quoted by PTI.

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Those involved in the study include researchers from the National Institute of Epidemiology.

The study was conducted on COVID-infected persons, both vaccinated and unvaccinated ones, in the Greater Chennai Corporation's triage centers between May 3 and 7.

COVID-19 Vaccine

Frequently Asked Questions

How does a vaccine work?

A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.

How many types of vaccines are there?

There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.

What does it take to develop a vaccine of this kind?

Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.

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