Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Clinical Microbiology & Public Health Laboratory, Public Health England, Cambridge, United Kingdom
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Clinical Microbiology & Public Health Laboratory, Public Health England, Cambridge, United Kingdom
Shaun Seaman
Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, United Kingdom
Richard J Samworth
Statistical Laboratory, Centre for Mathematical Sciences, University of Cambridge, Cambridge, United Kingdom
Ben Warne
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom; Department of Medicine, University of Cambridge, Cambridge, United Kingdom
Chris Workman
Occupational Health and Wellbeing, Cambridge Biomedical Campus, Cambridge, United Kingdom
Mark Ferris
Occupational Health and Wellbeing, Cambridge Biomedical Campus, Cambridge, United Kingdom
Jo Wright
Occupational Health and Wellbeing, Cambridge Biomedical Campus, Cambridge, United Kingdom
Natalie Quinnell
Occupational Health and Wellbeing, Cambridge Biomedical Campus, Cambridge, United Kingdom
Ashley Shaw
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom
Cambridge COVID-19 Collaboration
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Department of Medicine, University of Cambridge, Cambridge, United Kingdom
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom; Department of Medicine, University of Cambridge, Cambridge, United Kingdom
Rob Howes
Cambridge COVID-19 Testing Centre and AstraZeneca, Anne McLaren Building, Cambridge, United Kingdom
Giles Wright
Occupational Health and Wellbeing, Cambridge Biomedical Campus, Cambridge, United Kingdom
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom; Department of Medicine, University of Cambridge, Cambridge, United Kingdom; NHS Blood and Transplant, Cambridge, United Kingdom
Cambridge University NHS Hospitals Foundation Trust, Cambridge, United Kingdom; Department of Medicine, University of Cambridge, Cambridge, United Kingdom; Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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.