For the study, researchers at Pfizer and the University of Texas Medical Branch created genetically modified versions of the virus to carry some of the mutations found in B.1.351. They tested them on blood samples collected from 15 people who received two doses of the Pfizer / BioNTech vaccine as part of a clinical trial.
Although blood serum samples produce less neutralizing antibody activity, it was still enough to neutralize the virus, they wrote in a letter to the newspaper. This is in line with other studies. And it is very much in line with what is seen with other viruses, said one of the researchers.
“While we still don’t know exactly what level of neutralization is needed to protect against COVID-19 disease or infection, our experience with other vaccines tells us that the Pfizer vaccine is likely to offer relatively good protection against this new variant,” Scott Weaver, director of the Institute of Human Infections and Immunity at the University of Texas Medical Branch and author of the study, told CNN.
“The reduction in neutralization levels against 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 the SARS-CoV-2, “Weaver added.
Pfizer said there is no evidence in real life that the variant escapes the protection offered by its vaccine. “However, Pfizer and BioNTech are taking the necessary steps, making the right investments and engaging in the appropriate talks with regulators to be in a position to develop and seek authorization for an updated or enhanced mRNA vaccine once a strain that significantly reduces the protection of the vaccine is identified, “Pfizer said in a statement.
Separately, a team from the National Institutes of Health and Modern published a letter in the same newspaper describing the findings 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 enough of a reduction to make the vaccine work less effectively.
“Despite this reduction, levels of neutralizing titration 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 effectiveness against a variant first seen in the UK and known as B.1.1.7.