Covishield effectiveness in fully vaccinated 63% during 2nd wave: Study

The study was published in ‘The Lancet Infectious Diseases’ journal and it included a comparison between 2,379 cases of confirmed SARS-CoV-2 infection and 1,981 controls. The vaccine’s effectiveness against SARS-CoV-2 infection in fully vaccinated individuals was found to be 63 percent.

PTI

November 30, 2021 / 22:10 IST

(Represemtative Image Source: AP)

The vaccine effectiveness of Covishield against Covid-19 infection in fully vaccinated individuals was found to be 63 percent between April and May when the second wave was at its peak in India, according to a new study.

The study was published in ‘The Lancet Infectious Diseases’ journal and it included a comparison between 2,379 cases of confirmed SARS-CoV-2 infection and 1,981 controls. The vaccine’s effectiveness against SARS-CoV-2 infection in fully vaccinated individuals was found to be 63 percent.

The Science and Technology Ministry shared the study in an official statement.

“More importantly, the scientists also observed that the spike-specific T-cell responses were conserved against both the delta variant and wild-type SARS-CoV-2. Such cellular immune protection might compensate for waning humoral immunity against the virus variants and prevent moderate-to-severe disease and need for hospitalisation,” the study said.

The ministry said this study provides comprehensive data on the real-world vaccine effectiveness and immunological response to vaccination which should help guide policy. A multi-institutional team of Indian researchers led by the Translational Health Science and Technology Institute (THSTI) evaluated the real-world vaccine effectiveness of Covishield during the SARS-CoV-2 infection surge between April and May 2021 in India.

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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