Study registration: ISRCTN21086382
Publication Pouwels K, Nat Med, 2021
Dates: 2020-12-01 to 2021-08-01
Funding: Mixed (Department of Health and Social Care (UK), National Institute for Health Research Health Protection Research Unit (NIHR HPRU), Public Health England, NIHR Oxford Biomedical Research Centre, Huo Family Foundation,Medical Research Council UK, Wellcome, Robertson Fellowship.)
Conflict of interest: Yes (KBP and ASW are employees of the University of Oxford, but not involved in the development or production of the vaccine. ASW also received grants from Medical Research Council UK during the conduct of the study.)

Methods

Study design:Cohort
Description of participants: Adults from households randomly selected across the UK.
Inclusion criteria:
  • Currently resident in a household where a household member has participated in an ONS or NISRA Survey and has consented to be approached for future research or where the household has been randomly selected from databases of addresses
  • The analysis of vaccine effectiveness comparing Alpha-dominant and Delta-dominant periods included all individuals 18 years and older
  • analyses of the Delta-dominant period were also restricted to visits in those aged 18 to 64 years.

Exclusion criteria:
  • *

Follow-up duration (months): 8
Vaccines:
  • 1 or 2 doses of BNT162b2
  • 1 or 2 doses of ChAdOx1-S
  • 1 or 2 doses of mRNA-1273
Variant description :
Variant name: Alpha
Evidence: Indirect evidence (prevalence of variant in the population: 1 to 99%)
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: Yes, Data are still being collected for the COVID-19 Infection Survey. De-identified study data are available for access by accredited researchers in the ONS Secure Research Service (SRS).
Data accessibility: Contact Research.Support@ons.gov.uk or visit the SRS website, https://www.ons.gov.uk/aboutus/whatwedo/statistics/requestingstatistics/approvedresearcherscheme
General comment This is a strong, sophisticated analysis, although uncontrolled confounding cannot be ruled out given the observational nature of the data.