Accepted for Publication: February 23, 2022.
Published Online: April 20, 2022. doi:10.1001/jamacardio.2022.0583
Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2022 Karlstad Ø et al. JAMA Cardiology.
Corresponding Author: Rickard Ljung, MD, PhD, MPH, Division of Use and Information, Swedish Medical Products Agency, PO Box 26, SE-751 03 Uppsala, Sweden (rickard.ljung@lakemedelsverket.se).
Author Contributions: Drs Karlstad and Ljung had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Drs Karlstad, Hovi, and Husby contributed equally to this study and are considered co–first authors; Drs Hviid and Ljung contributed equally and are considered co–senior authors.
Concept and design: Karlstad, Hovi, Husby, Selmer, Nohynek, Sundström, Grünewald, Gulseth, Hviid, Ljung.
Acquisition, analysis, or interpretation of data: Karlstad, Hovi, Husby, Härkänen, Selmer, Pihlström, Hansen, Gunnes, Sundström, Wohlfahrt, Nieminen, Grünewald, Gulseth, Hviid, Ljung.
Drafting of the manuscript: Karlstad, Husby, Härkänen, Nohynek, Ljung.
Critical revision of the manuscript for important intellectual content: Karlstad, Hovi, Husby, Härkänen, Selmer, Pihlström, Hansen, Nohynek, Gunnes, Sundström, Wohlfahrt, Nieminen, Grünewald, Gulseth, Hviid.
Statistical analysis: Karlstad, Härkänen, Selmer, Pihlström, Hansen, Gunnes, Sundström, Grünewald, Ljung.
Obtained funding: Gulseth, Hviid.
Administrative, technical, or material support: Karlstad, Nohynek, Gulseth.
Supervision: Hovi, Husby, Nohynek, Wohlfahrt, Hviid, Ljung.
Conflict of Interest Disclosures: Dr Karlstad reported participating in research projects funded by Novo Nordisk and LEO Pharma, all regulator-mandated phase 4 studies with funds paid to his institution and outside the submitted work. Dr Hovi reported being affiliated with the Finnish Institute for Health and Welfare and was thus obligated by legislation to investigate the potential postmarketing harmful effects of vaccines during the conduct of the study. Dr Husby reported receiving funding from the Lundbeck Foundation. Dr Nohynek reported receiving nonfinancial support from WHO SAGE (Strategic Advisory Group of Experts) and the Global Advisory Committee on Vaccine Safety during the conduct of the study; and being employed by the Finnish Institute for Health and Welfare (THL), which receives research funding from Sanofi Pasteur, GlaxoSmithKline, and Pfizer for research studies not related to the current study nor to COVID-19. Dr Sundström reported participating in research funded by governmental agencies, universities, Astellas Pharma, Janssen Biotech, AstraZeneca, Pfizer, Roche, (then) Abbott Laboratories, (then) Schering-Plough, UCB Nordic, and Sobi, with all funds paid to Karolinska Institutet, outside the submitted work. Dr Nieminen reported receiving grants from Sanofi Pasteur outside the submitted work; and being employed by THL. Dr Grünewald reported being involved in the European Medicines Agency regulatory assessment of Comirnaty; being previously employed at a drug development consultancy firm with cross-product responsibilities; and being involved on a project for pertussis vaccines funded by Sanofi Pasteur, Merck Sharp & Dohme Corp, and GlaxoSmithKline at the Swedish Agency of Infectious Disease Control. Dr Gulseth reported participating in research projects and clinical trials funded by Novo Nordisk, GlaxoSmithKline, AstraZeneca, and Boehringer-Ingelheim paid to Oslo University Hospital; and receiving personal fees from Sanofi-Aventis. Dr Hviid reported receiving grants from The Lundbeck Foundation during the conduct of the study. Dr Ljung reported receiving grants from Sanofi Aventis paid to his institution outside the submitted work; and receiving personal fees from Pfizer outside the submitted work. No other disclosures were reported.
Additional Information: Among us, Dr Hviid had full access to all the Danish data, Dr Hovi had full access to all the Finnish data, Dr Karlstad had full access to all the Norwegian data, Dr Ljung had full access to all the Swedish data, and Dr Härkänen had full access to all the meta-analyses data in the study, and each investigator takes responsibility for the integrity of the data and the accuracy of the respective analyses. In addition, Drs Husby, Hansen, and Wohlfahrt, of the Statens Serum Institut, analyzed the Danish data and are responsible for those analyses; Drs Karlstad, Selmer, and Gunnes, of the Norwegian Institute of Public Health, conducted and are responsible for the analyses of the Norwegian data; Drs Hovi and Härkänen, of the Finnish Institute for Health and Welfare, conducted and are responsible for the analyses of the Finnish data; and Drs Pihlström, Sundström, Grünewald, and Ljung, of the Swedish Medical Products Agency, conducted and are responsible for the analyses of the Swedish data.