Vax-induced antibodies may be less effective against new Covid variants

New York, March 13 : Neutralizing antibodies induced by the Pfizer and Moderna Covid-19 vaccines were significantly less effective against the SARS-CoV-2 variants first described in Brazil/Japan and South Africa, say researchers.
The team used their experience measuring HIV neutralizing antibodies to create similar assays for Covid-19, comparing how well the antibodies worked against the original strain versus the new variants.
“We were able to leverage the unique high-throughput capacity that was already in place and apply it to SARS-CoV-2,” said researcher Alejandro Balazs from Massachusetts General Hospital in the US.
“When we tested these new strains against vaccine-induced neutralizing antibodies, we found that the three new strains first described in South Africa were 20-40 times more resistant to neutralization, and the two strains first described in Brazil and Japan were five to seven times more resistant, compared to the original SARS-CoV-2 virus,” Balazs added.
According to the study, published in the journal Cells, neutralizing antibodies work by binding tightly to the virus and blocking it from entering cells, thus preventing infection.
Like a key in a lock, this binding only happens when the antibody’s shape and the virus’s shape are perfectly matched to each other, the researcher said.