Covid-19 Living Data

Study registration: *
Publication Chung H, BMJ, 2021
Dates: 2020-12-14 to 2020-12-19
Funding: Public/non profit (Canadian Immunization Research Network (CIRN) through a grant from the Public Health Agency of Canada and the Canadian Institutes of Health Research; the Public Health Agency of Canada, through the Vaccine Surveillance Reference group and the COVID-19 Immunity Task Force; ICES, which is funded by an annual grant from Ontario’s Ministry of Health (MOH) and Ministry of Long term Care (MLTC); the Ontario Health Data Platform (OHDP), a Province of Ontario initiative to support Ontario’s ongoing response to covid-19 and its related impacts.)
Conflict of interest: Yes (KW is chief executive officer of CANImmunize and serves on the data safety board for the Medicago covid-19 vaccine trial. SMM has received unrestricted research grants from Merck, GlaxoSmithKline, Sanofi Pasteur, Pfizer, and Roche-Assurex for unrelated studies. SMM has received fees as an advisory board member for GlaxoSmithKline, Merck, Pfizer, Sanofi Pasteur, and Seqirus. CHR has received an unrestricted research grant from Pfizer for an unrelated study.)

Methods
Methods	Study design:Test-negative Description of participants: People with COVID-like symptoms and with no history of COVID-19 tested for SARS-CoV-2 Inclusion criteria: Living in Ontario, Canada aged ≥16 years eligible for provincial health insurance tested for SARS-CoV-2 between 14 December 2020 and 19 April 2021 at least one relevant covid-19 symptom (based on self-report or observation, such as measured temperature), at the time of testing. Exclusion criteria: Tested positive for SARS-CoV-2 before 14 December 2020 recipients of the ChAdOx1 (Oxford-AstraZeneca) vaccine living in long term care Follow-up duration (months): 4.2
Vaccines:	1 or 2 doses
Variant description :
Variant description :	Variant name: Alpha Evidence: Direct evidence (effectiveness determined by sequencing cases)
Documents available	Protocol NR Statistical plan NR Data-sharing stated: Yes Data accessibility: www.ices.on.ca/DAS (email das@ices.on.ca) The full dataset creation plan and underlying analytic code are available from the authors upon request, understanding that the computer programs might rely upon coding templates or macros that are unique to ICES and are therefore either inaccessible or require modification.
General comment	Some concerns regarding residual confounding, bias in the selection of participants into the study, missing data on variant type and assessment of the severe disease outcome.