Study registration: *
Publication Lumley S, Clin Infect Dis, 2021
Dates: 2020-09-01 to 2021-02-28
Funding: Public/non profit (UK Government’s Department of Health and Social Care; National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Healthcare Associated Infections and Antimicrobial Resistance at Oxford University in partnership with Public Health England (PHE); NIHR Biomedical Research Centre, Oxford; the Huo Family Foundation; Andrew Spokes. )
Conflict of interest: Yes (D. W. E. declares lecture fees from Gilead, outside the submitted work. R. J. C. is a founder, shareholder, and consultant to MIROBio, outside the submitted work. All other authors report no potential conflicts.)

Methods

Study design:Cohort
Description of participants: Staff at 4 hospitals and associated facilities in Oxfordshire, UK.
Inclusion criteria:
  • Healthcare workers
  • working at any of the 4 Oxford University Hospitals and associated facilities in Oxfordshire, UK
  • tested between September 1, 2020 to February 28, 2021.

Exclusion criteria:
  • Vaccination <14 days prior to testing
  • Previously seropositive for SAR-CoV-2.

Follow-up duration (months): 6.00
Vaccines:
  • 1 or 2 doses of BNT162b2 or ChAdOx1
Variant description :
Variant name: Alpha
Evidence: Indirect evidence (prevalence of variant in the population: 56%)
Documents
available

Protocol

NR

Statistical plan

NR

Data-sharing stated: Yes, Currently
Data accessibility: The data sets analyzed during the current study are not pub- licly available as they contain personal data but are available from the Infections in Oxfordshire Research Database (https://oxfordbrc.nihr.ac.uk/ research-themes-overview/antimicrobial-resistance-and-modernising- microbiology/infections-in-oxfordshire-research-database-iord/), subject to an application and research proposal meeting the ethical and governance requirements of the Database. Sequence data generated during the study are available from the European Nucleotide Archive under study accession number PRJEB43319

General comment In addition to the published report, the supplementary material were used in data extraction and risk of bias assessment. The prevalence reported for the Alpha variant was based on sequencing since December 1, 2020; however, results are for data from September 1, 2020.
The main concern is the potential for uncontrolled confounding. Although most confounders were adjusted for, the analysis did not control for symptoms at the time of potential vaccination, which is likely to be an important confounder.