Interim Estimates of Vaccine Effectiveness of Pfizer-BioNTech and Moderna COVID-19 Vaccines Among Health Care Personnel - 33 U.S. Sites, January-March 2021.

Journal Article (Journal Article)

Throughout the COVID-19 pandemic, health care personnel (HCP) have been at high risk for exposure to SARS-CoV-2, the virus that causes COVID-19, through patient interactions and community exposure (1). The Advisory Committee on Immunization Practices recommended prioritization of HCP for COVID-19 vaccination to maintain provision of critical services and reduce spread of infection in health care settings (2). Early distribution of two mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) to HCP allowed assessment of the effectiveness of these vaccines in a real-world setting. A test-negative case-control study is underway to evaluate mRNA COVID-19 vaccine effectiveness (VE) against symptomatic illness among HCP at 33 U.S. sites across 25 U.S. states. Interim analyses indicated that the VE of a single dose (measured 14 days after the first dose through 6 days after the second dose) was 82% (95% confidence interval [CI] = 74%-87%), adjusted for age, race/ethnicity, and underlying medical conditions. The adjusted VE of 2 doses (measured ≥7 days after the second dose) was 94% (95% CI = 87%-97%). VE of partial (1-dose) and complete (2-dose) vaccination in this population is comparable to that reported from clinical trials and recent observational studies, supporting the effectiveness of mRNA COVID-19 vaccines against symptomatic disease in adults, with strong 2-dose protection.

Full Text

Duke Authors

Cited Authors

  • Pilishvili, T; Fleming-Dutra, KE; Farrar, JL; Gierke, R; Mohr, NM; Talan, DA; Krishnadasan, A; Harland, KK; Smithline, HA; Hou, PC; Lee, LC; Lim, SC; Moran, GJ; Krebs, E; Steele, M; Beiser, DG; Faine, B; Haran, JP; Nandi, U; Schrading, WA; Chinnock, B; Henning, DJ; LoVecchio, F; Nadle, J; Barter, D; Brackney, M; Britton, A; Marceaux-Galli, K; Lim, S; Phipps, EC; Dumyati, G; Pierce, R; Markus, TM; Anderson, DJ; Debes, AK; Lin, M; Mayer, J; Babcock, HM; Safdar, N; Fischer, M; Singleton, R; Chea, N; Magill, SS; Verani, J; Schrag, S; Vaccine Effectiveness Among Healthcare Personnel Study Team,

Published Date

  • May 21, 2021

Published In

Volume / Issue

  • 70 / 20

Start / End Page

  • 753 - 758

PubMed ID

  • 34014909

Pubmed Central ID

  • PMC8136422

Electronic International Standard Serial Number (EISSN)

  • 1545-861X

Digital Object Identifier (DOI)

  • 10.15585/mmwr.mm7020e2


  • eng

Conference Location

  • United States