There’s more evidence that at least some of the current coronavirus vaccines protect people against the ever-changing variants of coronavirus.
Tests done using the blood of both people who had recovered from Covid-19 and those who had been vaccinated with Moderna’s vaccine showed big differences in how the immune system responded to mutations in the virus, Dr. Allison Greaney of the Fred Hutchinson Cancer Research Center and the University of Washington told a meeting of federal vaccine advisers.
“We know that the SARS-CoV-2 virus is evolving to evade antibody immunity,” Greaney told a meeting of the National Vaccine Advisory Committee, which advises the US Health and Human Services Department.
“What we found for the Moderna-1273 mRNA vaccine was that, overall, that antibody immunity elicited by this vaccine to be less affected by single mutations,” Greaney said.
The team, which is tracking viral mutations and their effects, made artificial versions of mutant virus and tested them against samples of blood. While some mutations caused a 30-fold loss of antibody effectiveness against the virus in the blood of people who had recovered from an infection, the loss of efficacy was far lower in the blood of people given two doses of Moderna vaccine, she said.
In some samples, there was no effect on the immunity – which suggested that the vaccine stimulates a broad immune response that covers the current mutations, she said.
“This suggests that the vaccine-elicited antibodies are much more broad and are less affected by single mutations,” Greaney told the meeting.
Federal officials have been urging Americans to get vaccinated quickly to stop the virus from circulating and acquiring the mutations that help it evade the immune system. Tests such as those done at the University of Washington lab support the idea that people who have been infected will be more vulnerable to catching variant versions of the virus than vaccinated people will be.