Repository logo

Efficacy of FFP3 respirators for prevention of SARS-CoV-2 infection in healthcare workers.

Published version

Change log


Ferris, Rebecca 
Workman, Chris 
Enoch, David A 


Background: Respiratory protective equipment recommended in the UK for healthcare workers (HCWs) caring for patients with COVID-19 comprises a fluid-resistant surgical mask (FRSM), except in the context of aerosol generating procedures (AGPs). We previously demonstrated frequent pauci- and asymptomatic severe acute respiratory syndrome coronavirus 2 infection HCWs during the first wave of the COVID-19 pandemic in the UK, using a comprehensive PCR-based HCW screening programme (Rivett et al., 2020; Jones et al., 2020). Methods: Here, we use observational data and mathematical modelling to analyse infection rates amongst HCWs working on 'red' (coronavirus disease 2019, COVID-19) and 'green' (non-COVID-19) wards during the second wave of the pandemic, before and after the substitution of filtering face piece 3 (FFP3) respirators for FRSMs. Results: Whilst using FRSMs, HCWs working on red wards faced an approximately 31-fold (and at least fivefold) increased risk of direct, ward-based infection. Conversely, after changing to FFP3 respirators, this risk was significantly reduced (52-100% protection). Conclusions: FFP3 respirators may therefore provide more effective protection than FRSMs for HCWs caring for patients with COVID-19, whether or not AGPs are undertaken. Funding: Wellcome Trust, Medical Research Council, Addenbrooke's Charitable Trust, NIHR Cambridge Biomedical Research Centre, NHS Blood and Transfusion, UKRI.


Funder: Addenbrooke's Charitable Trust, Cambridge University Hospitals; FundRef:

Funder: NIHR Cambridge Biomedical Research Centre


Research Advance, Epidemiology and Global Health, Microbiology and Infectious Disease, COVID-19, SARS-CoV-2, healthcare worker, PPE, mask, FFP3, Viruses

Journal Title


Conference Name

Journal ISSN


Volume Title



eLife Sciences Publications, Ltd
Wellcome Trust (108070/Z/15/Z)
Addenbrooke's Charitable Trust (ACT) (900275 Minute 47/20B)
Medical Research Council (MR/P008801/1)
MRC (via University of Warwick) (MR/V038613/1)