Study registration: *
Publication Lopez J, N Engl J Med, 2021
Dates: 26/10/2020 to 16/05/2021
Funding: Public/non profit (Funded by Public Health England)
Conflict of interest: no COI (The authors have declared no competing interest.)

Methods

Study design:Test-negative
Description of participants: Data on all symptomatic sequenced cases of COVID-19 in England
Inclusion criteria:
  • All positive PCR tests between 26 October 2020 and 16 May 2021
  • All negative community tests among individuals reporting symptoms were also extracted for the test negative case control analysis. Symptoms consistent with COVID-19: high temperature, new continuous cough, loss or change in sense of smell or taste.

Exclusion criteria:
  • Children aged under 16 years as of March 21st 2021 were excluded.
  • Data were restricted to individuals reporting symptoms and only individuals tested within 10 days of symptom onset were included to account for reduced sensitivity of PCR testing beyond this period.

Follow-up duration (months): 5
Vaccines:
  • 1 or 2 doses of BNT162b2
  • 1 or 2 doses of ChAdOx1-S
  • 1 or 2 doses of either BNT162b2 or ChAdOx1-S
Variant description :
Variant name: Delta
Evidence: Direct evidence (effectiveness determined by sequencing cases)
Documents
available

Protocol

NR

Statistical plan

NR

Data-sharing stated: NR
Data accessibility: "All relevant data are available in the manuscript or supplement"
General comment Some concerns over the possibility of uncontrolled confounding given the observational nature of the data, and uncertainty in how missing data were addressed.