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

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Seaman, Shaun 
Samworth, Richard J 
Warne, Ben 


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.



Research Advance, Epidemiology and Global Health, Microbiology and Infectious Disease, SARS-CoV-2, COVID-19, BNT162b2, vaccination, asymptomatic, Pfizer-BioNTech, Human

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eLife Sciences Publications, Ltd
Wellcome Trust (108070/Z/15/Z)
Wellcome Trust (207498/Z/17/Z)
Wellcome Trust (210688/Z/18/Z)
Medical Research Council (MR/P008801/1)
NHS Blood and Transplant (WPA15-02)
EPSRC (EP/P031447/1)
Medical Research Council (MC_UU_00002/10)
EPSRC (EP/N031938/1)