Study registration: ISRCTN, number 39557.
Publication Hyams C, Lancet Infect Dis, 2021
Dates: 2020-12-18 to 2020-02-26
Funding: Private (Pfizer)
Conflict of interest: Yes (CH is principal investigator of the Avon CAP study which is an investigator-led University of Bristol study funded by Pfizer and has previously received support from the NIHR in an academic clinical fellowship. JO is a co-investigator on the Avon CAP study.)

Methods

Study design:Test-negative
Description of participants: Adults >80 years who were admitted to hospital in two NHS trusts in Bristol, UK with signs and symptoms of respiratory disease(test-positive/negative)
Inclusion criteria:
  • "adults admitted to one hospital (Southmead Hospital) in North Bristol NHS Trust or one hospital (Bristol Royal Infirmary) in University Hospitals Bristol and Weston NHS Foundation Trust with signs and symptoms of respiratory disease between Dec 18, 2020 (ie, 10 days after administration of BNT162b2 started), and Feb 26, 2021, inclusive" (including test-positive and test-negative)

Exclusion criteria:
  • Patients who developed symptoms before receiving their vaccine or those who received their vaccine after admission were excluded, as were those with symptoms that started more than 10 days before admission to avoid including patients with potentially false negative admission SARS-CoV-2 tests. To avoid bias due to nosocomial infection, readmissions data were excluded (ie, only the first admission of each patient was counted).

Follow-up duration (months): 2
Vaccines:
  • 1 dose of BNT162b2
  • 1 dose of ChAdOx1-S
Variant description :
Variant name: Alpha
Evidence: Indirect evidence (prevalence of variant in the population: 40 to 95%)
Documents
available

Protocol

NR

Statistical plan

NR

Data-sharing stated: No
Data accessibility: NR
General comment Some concerns around bias in selection of participants into the study (test-negative design).