New Evidence Shows COVID-19 Antibodies, Less Effective Vaccines Against Variants – Manila Bulletin

CHICAGO, United States (Xinhua) – Research by Washington University School of Medicine in St. Louis indicates that three new variants of the rapidly spreading virus that cause COVID-19 may evade antibodies that work against the original form of the virus. virus that triggered the pandemic.

To assess whether the new variants could evade the antibodies produced to the original form of the virus, the researchers tested the antibodies’ ability to neutralize three variants of the virus in the laboratory.

The researchers tested the variants against antibodies in the blood of people who had recovered from SARS-CoV-2 infection or who were vaccinated with the Pfizer vaccine. They also tested antibodies in the blood of mice, hamsters and monkeys that had been vaccinated with an experimental COVID-19 vaccine, developed at the University of Washington School of Medicine, that can be administered through the nose.

The B.1.1.7 variant (found in Great Britain) could be neutralized with levels similar to those required to neutralize the parent virus. But the other two variants required 3.5 to 10 times more antibodies for neutralization.

The researchers then tested monoclonal antibodies – mass-produced replicas of individual antibodies that are exceptionally good at neutralizing the original virus. When the researchers tested the new viral variants against a panel of monoclonal antibodies, the results ranged from widely effective to completely ineffective.

Since each virus variant carried multiple mutations in the spike gene, the researchers created a panel of viruses with unique mutations in order to analyze the effect of each mutation. Most of the variation in antibody efficacy could be attributed to a single amino acid change in the peak protein. This change, called E484K, was found in variants B.1.135 from South Africa and B.1.1.248 from Brazil, but not B.1.1.7 from Great Britain.

Variant B.1.135 is widespread in South Africa, which may explain why one of the vaccines tested in people was less effective in South Africa than in the United States, where the variant is still rare, said lead author Michael S. Diamond. .

“We still don’t know exactly what the consequences of these new variants will be,” said Diamond, also a professor of molecular microbiology and of pathology and immunology. “It is clear that we will need to continually screen for antibodies to make sure they continue to work as new variants emerge and spread and potentially adjust our antibody and vaccine treatment strategies.”

The findings are published Thursday in Nature Medicine.