Not a single vaccinated doctor who contracted COVID-19 was hospitalized or died.
Infections in health workers fully vaccinated against COVID-19 are extremely rare, according to a new study.
Researchers examined data from employee health records of more than 36,600 health professionals in California and found that less than 1% tested positive for COVID-19 after being fully vaccinated – meaning both doses plus two weeks for immunity to build up – with the Pfizer or Moderna vaccines.
While anecdotal reports of individual doctors who received COVID-19 after receiving one or both doses of the vaccine have recently made headlines, the study offers a more comprehensive look at how common such post-vaccination infections occur in fully vaccinated people.
“This study confirms that the vaccines are very effective in preventing COVID-19,” said study authors Dr. Shira Abeles and Dr. Francesca Torriani on ABC News.
“It also reminds that vaccines are not 100% effective and that there are ‘breakthrough’ cases,” added the doctors, noting that public health measures must remain in place to protect against stray cases.
They also pointed to a cause for optimism. “The vaccines showed strong efficacy in a spate of cases in Southern California, which is great news for all of us,” said Abeles and Torriani, who both work at UC San Diego Health.
The study period lasted from December 16, 2020, when the University of California, San Diego (UCSD) and the University of California, Los Angeles (UCLA) began their vaccination programs, to February 9, 2021.
After complete vaccination, the risk of testing positive for the virus was 1.19% among UCSD employees and 0.97% among UCLA employees.
The study also showed that the further along the vaccination process the health care providers were, the better the vaccine worked.
Of the 36,659 workers vaccinated, 379 tested positive after their first vaccination dose, with the majority of those individuals testing positive within two weeks of their first injection. After receiving both doses of the dual vaccine, 37 people tested positive, the majority of which tested positive less than a week after their second dose. Only seven health professionals tested positive 15 days or more after their second vaccination.
Not a single vaccinated health worker who contracted COVID-19 was hospitalized or died, and those who did get sick were found to have milder symptoms than the unvaccinated, the researchers said.
“We really hope this will increase confidence in the vaccine,” said Abeles and Torriani.
There were limitations to the study. Health professionals who tested positive after one dose may have been exposed to the virus before they were vaccinated. It is also not known which virus variants were circulating during the study period. The research was published Tuesday in a letter to the New England Journal of Medicine.