The study was made possible thanks to the collaboration of the Paediatric Investigators Collaborative Network on Infections in Canada (PICNIC) and the manuscript was written on behalf of PICNIC.
The authors declare that no funds, grants, or other support were received for this project during the preparation of this manuscript.
Financial interests: E. Ann Yeh reports grants from Biogen, Roche, Horizon Therapeutics and Alexion; honoraria from Prime and Novartis; and participation on advisory boards with Roche and Horizon Therapeutics. Jesse Papenburg reports grants from AbbVie, Sanofi Pasteur, Merck and MedImmune; consulting fees from Merck; and honoraria from AbbVie, AstraZeneca and Seegene. He is a member of the National Advisory Committee on Immunization. Marie-Astrid Lefebvre reports an honorarium from Takeda Canada. Tammie Dewan reports grants from the Sick Kids Hospital Foundation, the Canadian Institutes for Health Research (CIHR) and the Department of Pediatrics at the University of Calgary. Jared Bullard reports grants from CIHR, the Manitoba Medical Service Foundation and Research Manitoba. Manish Sadarangani reports grants from GlaxoSmithKline, Merck, Moderna, Pfizer, Sanofi Pasteur, Seqirus, Symvivo and VBI Vaccines, as well as participating on 2 data safety monitoring boards for COVID-19 vaccine trials. Rupeena Purewal reports honoraria and consulting fees from Verity Pharmaceuticals. Kirk Leifso reports a grant from the Hospital for Sick Children. Joanna Merckx reports a role as medical director of bioMerieux Canada. She is also an independent researcher, with a contract with Public Health Belgium, Sciensano for a study on the seroprevalence of SARS-CoV-2 in schools.
Joan Robinson conceptualized and designed the study, acquired data, wrote the first draft of the manuscript, approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.
Michelle Barton conceptualized and designed the study, acquired data and reviewed and revised the manuscript, approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.
Drs Morris, Bitnun, Gill, El Tal, Laxer, Yeh, Yea, Ulloa-Gutierrez, Brenes-Chacon, Yock-Corrales, Ivankovich-Escoto , Soriano-Fallas, Hernandez-de Mezerville, Papenburg, Lefebvre, Nateghian, Aski, Manafi, Dwilow, Bullard, Cooke, Dewan, Restivo, Lopez, Sadarangani, Roberts, Le Saux, Bowes, Purewal, Lautermilch, Wong, Piche, Top, Leifso, Foo, and Panetta provided input on the case report form, acquired or supervised the acquisition of data, reviewed and revised the manuscript, approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.
Dr Merckx contributed to analysis and interpretation of the data, reviewed and revised the manuscript, approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.
This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Health Research Ethics Board of the University of Alberta (March 2020/ Pro00099426) and subsequently by the ethics committee at each participating site.
Consent to participate
The need to obtain written consent from patients or parents was waived by the ethics committee at all participating sites.