Kim SS, Chung JR, Belongia EA, McLean HQ, King JP, Nowalk MP, Zimmerman RK, Balasubramani GK, Martin ET, Monto AS, Lamerato LE, Gaglani M, Smith ME, Dunnigan KM, Jackson ML, Jackson LA, Tenforde MW, Verani JR, Kobayashi M, Schrag S, Patel MM, and Flannery B. mRNA Vaccine Effectiveness against COVID-19 among Symptomatic Outpatients Aged ≥16 Years in the United States, February - May 2021. J Infect Dis 2021.
The Journal of infectious diseases
Evaluations of vaccine effectiveness (VE) are important to monitor as COVID-19 vaccines are introduced in the general population. Research staff enrolled symptomatic participants seeking outpatient medical care for COVID-19-like illness or SARS-CoV-2 testing from a multisite network. VE was evaluated using the test-negative design. Among 236 SARS-CoV-2 nucleic acid amplification test-positive and 576 test-negative participants aged ≥16 years, VE of mRNA vaccines against COVID-19 was 91% (95% CI: 83-95) for full vaccination and 75% (95% CI: 55-87) for partial vaccination. Vaccination was associated with prevention of most COVID-19 cases among people seeking outpatient medical care.
ePub ahead of print