Interim Estimates of Vaccine Effectiveness of BNT162b2 and mRNA-1273 COVID-19 Vaccines in Preventing SARS-CoV-2 Infection Among Health Care Personnel, First Responders, and Other Essential and Frontline Workers — Eight U.S. Locations, December 2020–March 2021

Mark G. Thompson, Jefferey L. Burgess, Allison L. Naleway, Harmony L. Tyner, Sarang K. Yoon, Jennifer Meece, Lauren E.W. Olsho, Alberto J. Caban-Martinez, Ashley Fowlkes, Karen Lutrick, Jennifer L. Kuntz, Kayan Dunnigan, Marilyn J. Odean, Kurt T. Hegmann, Elisha Stefanski, Laura J. Edwards, Natasha Schaefer-Solle, Lauren Grant, Katherine Ellingson, Holly C. GroomTnelda Zunie, Matthew S. Thiese, Lynn Ivacic, Meredith G. Wesley, Julie Mayo Lamberte, Xiaoxiao Sun, Michael E. Smith, Andrew L. Phillips, Kimberly D. Groover, Young M. Yoo, Joe Gerald, Rachel T. Brown, Meghan K. Herring, Gregory Joseph, Shawn Beitel, Tyler C. Morrill, Josephine Mak, Patrick Rivers, Katherine M. Harris, Danielle R. Hunt, Melissa L. Arvay, Preeta Kutty, Alicia M. Fry, Manjusha Gaglani

Research output: Contribution to journalArticlepeer-review

269 Scopus citations

Abstract

On March 29, 2021, this report was posted as an MMWR Early Release on the MMWR website (https://www.cdc.gov/mmwr) Messenger RNA (mRNA) BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) COVID-19 vaccines have been shown to be effective in preventing symptomatic COVID-19 in randomized placebo-controlled Phase III trials (1,2); however, the benefits of these vaccines for preventing asymptomatic and symptomatic SARS-CoV-2 (the virus that causes COVID-19) infection, particularly when administered in real-world conditions, is less well understood. Using prospective cohorts of health care personnel, first responders, and other essential and frontline workers* in eight U.S. locations during December 14, 2020–March 13, 2021, CDC routinely tested for SARS-CoV-2 infections every week regardless of symptom status and at the onset of symptoms consistent with COVID-19–associated illness. Among 3,950 participants with no previous laboratory documentation of SARS-CoV-2 infection, 2,479 (62.8%) received both recommended mRNA doses and 477 (12.1%) received only one dose of mRNA vaccine.† Among unvaccinated participants, 1.38 SARS-CoV-2 infections were confirmed by reverse transcription–polymerase chain reaction (RT-PCR) per 1,000 person-days.§ In contrast, among fully immunized (≥14 days after second dose) persons, 0.04 infections per 1,000 person-days were reported, and among partially immunized (≥14 days after first dose and before second dose) persons, 0.19 infections per 1,000 persondays were reported. Estimated mRNA vaccine effectiveness for prevention of infection, adjusted for study site, was 90% for full immunization and 80% for partial immunization. These findings indicate that authorized mRNA COVID-19 vaccines are effective for preventing SARS-CoV-2 infection, regardless of symptom status, among working-age adults in real-world conditions. COVID-19 vaccination is recommended for all eligible persons.

Original languageEnglish (US)
Pages (from-to)495-500
Number of pages6
JournalMMWR Surveillance Summaries
Volume70
Issue number13
DOIs
StatePublished - 2021

ASJC Scopus subject areas

  • Epidemiology
  • Health(social science)
  • Health, Toxicology and Mutagenesis
  • Health Information Management

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