For the study, researchers at Pfizer and the University of Texas Medical Branch genetically modified versions of the virus to carry some of the mutations found in B.1.351. They tested them against blood samples taken from 15 people who received two doses of the Pfizer / BioNTech vaccine as part of a clinical trial.
While blood serum samples produced less neutralizing antibody activity, it was still enough to neutralize the virus, they wrote in a letter to the journal. This is consistent with other studies. And it is good in what is seen with other viruses, said one of the researchers.
“Although we do not yet know exactly what level of neutralization is required to protect against COVID-19 disease or infection, our experience with other vaccines tells us that the Pfizer vaccine is likely to provide relatively good protection against this new variant,” Scott Weaver said. director of the Institute for Human Infections and Immunity at the University of Texas Medical Branch and author of the study, he told CNN.
“The reduction in neutralization levels compared to the South African variant of about 2/3 is quite small compared to the variations in neutralization levels generated by vaccines against other viruses that have even more variability in their protein sequences than SARS-CoV-2.” . Weaver added.
Pfizer said there was no real-life evidence that the variant escaped the protection offered by its vaccine. “However, Pfizer and BioNTech shall take the necessary steps, make the right investments and engage in appropriate conversations with regulators to be able to develop and apply for an updated vaccine or mRNA booster once a strain that Significantly reduces vaccine protection is identified, “Pfizer said in a statement.
Separately, a team from the National Institutes of Health and Modernity published a letter in the same journal, presenting the results of an experiment they reported last month. They also reported a reduction in the antibody response to genetically engineered viruses to look like variant B.1.351 – but not a sufficient reduction to make the vaccine less effective.
“Despite this reduction, the levels of neutralization of securities with (the variant discovered in South Africa) remain above the levels that are expected to be protective,” the company said in a statement.
They found no reduction in efficacy compared to a variant first seen in the UK and known as B.1.1.7.