Moneycontrol PRO
you are here: HomeNewsTrendsHealth

Pfizer jab less effective, still protects against strain found in India: Study

The study sampled 28 healthcare workers in the city of Orleans. Sixteen of them had received two doses of the Pfizer vaccine, while 12 had received one dose of the AstraZeneca vaccine.

May 30, 2021 / 07:37 AM IST

The Pfizer vaccine is slightly less effective but appears to still protect against the more transmissible Indian strain of the virus that causes COVID-19, according to a  study by France's  Pasteur Institute.

"Despite slightly diminished efficacy, the Pfizer vaccine probably protects" against the variant found in India, according to laboratory test results, said Olivier Schwartz, the institute's director and co-author of the study that was published on the BioRxiv website ahead of peer review.

The study sampled 28 healthcare workers in the city of Orleans. Sixteen of them had received two doses of the Pfizer vaccine, while 12 had received one dose of the AstraZeneca vaccine.

Follow our LIVE blog for latest updates of the novel coronavirus pandemic

People who had received two doses of Pfizer saw a three-fold reduction in their antibodies against the B.1.617 variant, according to the study, but were still protected.

Close

COVID-19 Vaccine

Frequently Asked Questions

View more
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.

View more
Show

"The situation was different with the AstraZeneca vaccine, which induced particularly low levels of antibodies neutralising" the B.1.617 variant, the study said.

Patients who had had COVID-19 within the past year and people vaccinated with two doses of Pfizer retained enough antibodies to be protected against the variant found in India, but three to six times less antibodies than against the UK variant, Schwartz said.

The study shows that "this variant.. has acquired partial resistance to antibodies," Schwartz said.

Since first emerging in late 2019 in China, the SARS-CoV-2 virus that causes COVID-19 has developed several variants, usually named for the places where it first appeared including the so-called South Africa and UK strains.

The variant first detected in India appears to be much more transmissible than earlier variations.

It has now been officially recorded in 53 territories, according to a World Health Organization report.

To try to curb its spread, France and Germany have re-introduced tighter rules on arrivals from affected countries, including the United Kingdom.

Follow our full coverage of the coronavirus pandemic here.
AFP
first published: May 29, 2021 06:15 pm

stay updated

Get Daily News on your Browser
Sections
ISO 27001 - BSI Assurance Mark