Single-dose BNT162b2 vaccine protects against asymptomatic SARS-CoV-2 infection

Elife. 2021 Apr 8;10:e68808. doi: 10.7554/eLife.68808.


The BNT162b2 mRNA COVID-19 vaccine (Pfizer-BioNTech) is being utilised internationally for mass COVID-19 vaccination. Evidence of single-dose protection against symptomatic disease has encouraged some countries to opt for delayed booster doses of BNT162b2, but the effect of this strategy on rates of asymptomatic SARS-CoV-2 infection remains unknown. We previously demonstrated frequent pauci- and asymptomatic SARS-CoV-2 infection amongst healthcare workers (HCWs) during the UK's first wave of the COVID-19 pandemic, using a comprehensive PCR-based HCW screening programme (Rivett et al., 2020; Jones et al., 2020). Here, we evaluate the effect of first-dose BNT162b2 vaccination on test positivity rates and find a fourfold reduction in asymptomatic infection amongst HCWs ≥12 days post-vaccination. These data provide real-world evidence of short-term protection against asymptomatic SARS-CoV-2 infection following a single dose of BNT162b2 vaccine, suggesting that mass first-dose vaccination will reduce SARS-CoV-2 transmission, as well as the burden of COVID-19 disease.

Keywords: BNT162b2; COVID-19; Pfizer-BioNTech; SARS-CoV-2; asymptomatic; epidemiology; global health; human; infectious disease; microbiology; vaccination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asymptomatic Infections / therapy
  • BNT162 Vaccine
  • COVID-19 / diagnosis
  • COVID-19 / prevention & control*
  • COVID-19 Vaccines / administration & dosage
  • COVID-19 Vaccines / therapeutic use*
  • Health Personnel
  • Humans
  • Immunization Schedule
  • Immunization, Secondary
  • SARS-CoV-2 / isolation & purification
  • Vaccination


  • COVID-19 Vaccines
  • BNT162 Vaccine