THE Pfizer vaccine is slightly less effective against the more transmissible Indian strain of the Covid-19 virus, a study by France's Pasteur Institute said, adding that it still “probably protects” against the strain.
Olivier Schwartz, the institute's director and a co-author, wrote in the study that “despite slightly diminished efficacy, the Pfizer vaccine probably protects" against the Indian variant as well.
Published on the BioRxiv website ahead of a peer review, the study is based on samples of 28 healthcare workers in the city of Orlean, with 16 receiving two doses of the Pfizer vaccine, and 12 receiving one dose of the AstraZeneca vaccine.
People who received two doses of Pfizer saw a three-fold reduction in their antibodies against the Indian variant, also known as B.1.617, but were still protected, the study said.
"The situation was different with the AstraZeneca vaccine, which induced particularly low levels of antibodies neutralising" the Indian variant, the study said.
Patients who had Covid-19 within the past year and people vaccinated with two doses of Pfizer retained enough antibodies to be protected against the Indian variant, but three to six times fewer antibodies than against the UK variant, Schwartz said.
The study also mentioned that the new Indian variant “has acquired partial resistance to antibodies.” Schwartz added that the rapid spread of the Indian variant is associated with its ability to "escape" the effect of neutralising antibodies.
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 and is said to be one of the prime reasons behind the deadly ongoing second wave in India.
The variant has now been officially recorded in 53 territories, according to a World Health Organization report.
Cases of the Indian variant in the UK doubled to almost 7,000 last week, Public Health England said, sparking fresh concerns over stage four of prime minister Boris Johnson’s roadmap out of lockdown.
