Study registration: *
Publication Skowronski DM, medRxiv, 2021
Dates: 2021-03-01 to 2021-10-02
Funding: Public/non profit (Provincial health authorities )
Conflict of interest: Yes (GDS received a grant paid to his institution for a meningococcal seroprevalence study from Pfizer in 2016. MK received grants/contracts paid to his institution from Roche, Hologic and Siemens, unrelated to this work. MS has been an investigator on projects, unrelated to the current work, funded by GlaxoSmithKline, Merck, Pfizer, Sanofi-Pasteur, Seqirus, Symvivo and VBI Vaccines. All funds have been paid to his institute, and he has not received any personal payments. RG received honoraria for an RSV Coordinators Workshop funded by AbbVie. Other authors have no conflicts of interest to disclose.)
Description of participants: SARS-CoV-2 test-positive cases and test-negative controls 18 years and over residing in British Columbia, Canada
Follow-up duration (months): 7.2
|Variant description :
Variant name: Delta|
Evidence: Direct evidence (effectiveness determined by sequencing cases)
The pre-print article and supplementary material were used in data extraction and risk of bias assessment. The study assessed SARS-CoV-2 infection and hospitalization vaccine effectiveness in British Columbia (analysed here) and Quebec (analysed separately) using a test-negative case control design adjusting for age, sex, week, and region.
Concerns over uncontrolled confounding and the lack of a statistical analysis plan.