Health care workers at a California hospital saw daily COVID-19 cases among them drop drastically after vaccines became available, a new study suggests.
Researcher analyzed COVID-19 testing data among hospital staff at University of California Irvine Health in Orange County.
They found that positive cases among the workers had a steep drop off once they started getting the second shot of either the Pfizer-BioNTech or Moderna vaccine.
After three weeks, the rate of positive cases had fallen by 94 percent.
COVID cases dramatically dropped in the weeks after the second dose became available to UCI hospital employees
Test positivity rate dropped to zero in the weeks following the second dose's availability
For the study, published in JAMA Network Open, the team gathered data from November 2020 to March 2021.
At the hospital, employees were tested if they reported symptoms of COVID-19, and there was also randomly administered asymptomatic testing performed every week.
From November into early January, the trend of cases detected among employees followed county-wide trends.
While the county recorded 2,000 cases per day in late November to 4,000 per day in late December, the hospital saw about 10 per day in November and 18 in December.
The second dose became available to staff in the first week of January and, a week later, cases in the hospital began to diverge from the county.
After one week, daily cases in the hospital
