Among 417 workers at Rockefeller University who were fully vaccinated with either Pfizer or Moderna shots, two or about .5%, later developed infections, according to the study published Wednesday in the New England Journal of Medicine.
“We have characterized bona fide examples of vaccine outbreaks appearing as clinical symptoms,” the researchers wrote in their study. “These observations do not undermine the importance of urgent efforts at the federal and state levels to vaccinate the US population. They also support efforts to promote consolidation of a new vaccine (as well as a pan-coronavirus vaccine) to provide more protection against fluctuations. “
The researchers, from Rockefeller University, found that coronavirus variants with several variants of the original virus caused the breakthrough infections.
A variant infected one of the patients with the E484K mutation, which was first discovered in the B.1.351 variant originally identified in South Africa. E484K has been called an “escape mutant” because it has shown that it can escape some of the antibodies produced by coronavirus vaccines. One of the mutations found in the infections of participants in both studies involved D614G, which emerged early in the pandemic.
One of the pioneering infections was in a healthy 51-year-old woman who received her second dose of the Moderna vaccine on February 19. Nineteen days later, she tested positive for Covid-19 on March 10 after developing symptoms.
The other groundbreaking infection was in a healthy 65-year-old woman who received her second dose of the Pfizer vaccine on Feb. 9. She later learned that her unvaccinated partner had tested positive for Covid-19 on March 3. In the following days, the woman developed symptoms herself. It tested positive for Covid-19 on March 17.
More research is needed to determine whether similar findings concerning infections or innovative variants would emerge among a larger group of participants from different parts of the United States.
Experts say some innovative cases of Covid-19 are expected in fully vaccinated people, because no vaccine is 100% effective.
The CDC said that there had been pioneering cases in people of all ages who had been vaccinated, but that just over 40% were in people aged 60 and over. They were also more common among women and 29% were disproportionate.
The agency said it has developed a national database of Covid-19 innovations so that state health departments can report them
“Vaccine cut-off infections are a small percentage of people who are fully vaccinated. CDC recommends that all eligible persons receive a COVID-19 vaccine as soon as one is available to them,” the CDC said in a statement in CNN.
Ben Tinker and Maggie Fox of CNN contributed to this report.