Study registration: *
Publication Amirthalingam G, medRxiv, 2021
Dates: 2021-02-01 to 2021-06-20
Funding: Public/non profit (Public Health England)
Conflict of interest: Yes (MER reports that the Immunisation and Countermeasures Division (PHE) has provided vaccine manufacturers with post-marketing surveillance reports on pneumococcal and meningococcal infection, which the companies are required to submit to the UK licensing authority in compliance with their risk management strategy. A cost-recovery charge is made for these reports. EL report that the PHE Vaccine Evaluation Unit does contract research on behalf of GlaxoSmithKline, Sanofi, and Pfizer, which is outside the submitted work.)

Methods

Study design:Test-negative
Description of participants: Healthy adults aged 50-64 years in England
Inclusion criteria:
  • Healthy
  • aged 50-64 years
  • in England, UK
  • symptomatic within 10 days of COVID symptom onset
  • tested between February 1 to June 20, 2021.

Exclusion criteria:
  • A previous positive PCR or antibody result prior to 8 December 2020.

Follow-up duration (months): 4.63
Vaccines:
  • 1 or 2 doses of BNT162b2
  • 1 or 2 doses of ChAdOx1-S
Variant description :
Variant name: Alpha
Evidence: Indirect evidence (prevalence of variant in the population: *)
Documents
available

Protocol

NR

Statistical plan

No

Data-sharing stated: Yes
Data accessibility: Applications for relevant anonymised data should be submitted to the Public Health England Office for Data Release. Corresponding author: Gayatri Amirthalingam at gayatri.amirthalingam@phe.gov.uk
General comment In addition to the preprint, the supplementary material were used in data extraction and risk of bias assessment. Results were extracted for the subgroup aged 50-64; and for 1st dose 14-27 days since dose; or 2nd dose 65-84 days between doses with >=14 days since 2nd dose. Some cases were Delta variant instead but the prevalence was not reported.

Almost all confounding domains were controlled for, except symptoms at the time of intended vaccination. There is some potential for selection bias inherent to test-negative design. Protocol was not available.