Nearly 83 million Americans have received at least one dose of a Covid vaccine, and it’s unclear just how many of them will have a “breakthrough” infection, though two new reports suggest the number is very small.
One study found that just four out of 8,121 fully vaccinated employees at the University of Texas Southwestern Medical Center in Dallas became infected. The other found that only seven out of 14,990 workers at UC San Diego Health and the David Geffen School of Medicine at the University of California, Los Angeles tested positive two or more weeks after receiving a second dose of either the Pfizer-BioNTech or Moderna vaccines. Both reports, published on [March 23] in the New England Journal of Medicine, show how well the vaccines work in the real world, and during a period of intense transmission.
But these breakthrough cases, though quite rare, are a sharp reminder that vaccinated people are not invincible, especially when the virus continues to circulate widely.
“We felt really strongly that this data should not lead people to say, ‘Let’s all get vaccinated and then we can all stop wearing masks,’” said [infectious disease specialist] Dr. Francesca J. Torriani… “These measures have to continue until a larger segment of the population is vaccinated.”
