mRNA Vaccines Effective for Preventing Symptomatic COVID-19
Vaccine effectiveness 82 and 94 percent for single dose, two doses among U.S. health care personnel at 33 sites across 25 U.S. states
TUESDAY, May 18, 2021 (HealthDay News) -- For health care personnel (HCP), the vaccine effectiveness (VE) of authorized mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) against symptomatic COVID-19 illness is 82 and 94 percent for a single dose and for two doses, respectively, according to research published in the May 14 early-release issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Tamara Pilishvili, Ph.D., from the CDC COVID-19 Response Team, and colleagues conducted a test-negative case-control study to evaluate mRNA COVID-19 VE against symptomatic illness among HCP at 33 U.S. sites across 25 states.
The researchers found that after adjustment for age, race/ethnicity, and underlying medical conditions, the VE of a single dose (measured 14 days after the first dose through six days after the second dose) was 82 percent in interim analyses. The adjusted VE was 94 percent for two doses (measured at least seven days after the second dose).
"These interim results demonstrate that complete vaccination with authorized mRNA COVID-19 vaccines is highly effective in preventing symptomatic COVID-19 among HCP, supporting the results of phase III trials and additional accruing evidence in recent observational studies," the authors write. "In addition to adherence to recommended infection control and prevention practices, a critical component of controlling the U.S. COVID-19 pandemic and protecting HCP is ensuring high coverage with safe and effective COVID-19 vaccines."