The profile of the COvid-19 VACcination register SAFEty study in Sweden (CoVacSafe-SE)

  • Rickard Ljung Swedish Medical Products Agency, Uppsala, Sweden
  • Anders Sundström Swedish Medical Products Agency, Uppsala, Sweden
  • Maria Grünewald Swedish Medical Products Agency, Uppsala, Sweden
  • Charlotte Backman Swedish Medical Products Agency, Uppsala, Sweden
  • Nils Feltelius Swedish Medical Products Agency, Uppsala, Sweden
  • Rolf Gedeborg Swedish Medical Products Agency, Uppsala, Sweden
  • Björn Zethelius Swedish Medical Products Agency, Uppsala, Sweden
Keywords: COVID-19, SARS-CoV-2, pharmacovigilance, epidemiological, surveillance, monitoring, safety, efficacy, vaccine, signal detection


Background: The coronavirus disease 2019 (COVID-19) vaccines have been rapidly implemented in national vaccination programs world-wide after accelerated approval processes. The large population exposure achieved in very short time requires systematic monitoring of safety. The Swedish Medical Products Agency has launched a project platform for epidemiological surveillance to detect and characterise suspected adverse effects of COVID-19 vaccines in Sweden.

Methods: The platform includes all individuals 12 years or older in Sweden in 2021 and will be updated annually. Data, including vaccine and COVID-19 disease data, socioeconomic and demographic data, comorbidity, prescribed medicines and healthcare utilisation outcomes, are obtained from several national registers in collaboration with other Swedish Government agencies. Data from 2015 to 2019 are used as a historical comparison cohort unexposed to both the COVID-19 pandemic and to the COVID-19 vaccines.

Results: The primary study cohort includes 8,305,978 adults 18 years and older permanently residing in Sweden on 31 December 2020. The historical control cohort includes 8,679,641 subjects. By 31 July 2021, around 50% of those 18 years and older and two-thirds of those 50 years and older were vaccinated with at least one dose, 90% of those 70 years or older had two doses.

Conclusions: The nationwide register-based study cohort created by the Swedish Medical Products Agency with regular updates of individual level linkage of COVID-19 vaccination exposure data to other health data registers will facilitate both safety signal detection and evaluation and other pharmacoepidemiological studies.


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  1. World Health Organization. Coronavirus (COVID-19) dashboard. Available from: [cited 23 October 2021].

  2. Nohynek H, Jokinen J, Partinen M, Vaarala O, Kirjavainen T, Sundman J, et al. AS03 adjuvanted AH1N1 vaccine associated with an abrupt increase in the incidence of childhood narcolepsy in Finland. PLoS One 2012;7:e33536. doi: 10.1371/journal.pone.0033536

  3. Partinen M, Saarenpää-Heikkilä O, Ilveskoski I, Hublin C, Linna M, Olsén P, et al. Increased incidence and clinical picture of childhood narcolepsy following the 2009 H1N1 pandemic vaccination campaign in Finland. PLoS One 2012;7:e33723. doi: 10.1371/journal.pone.0033723

  4. Persson I, Granath F, Askling J, Ludvigsson JF, Olsson T, Feltelius N. Risks of neurological and immune-related diseases, including narcolepsy, after vaccination with Pandemrix: a population- and registry-based cohort study with over 2 years of follow-up. J Intern Med 2014;275:172–90. doi: 10.1111/joim.12150

  5. Feltelius N, Persson I, Ahlqvist-Rastad J, Andersson M, Arnheim-Dahlström L, Bergman P, et al. A coordinated cross-disciplinary research initiative to address an increased incidence of narcolepsy following the 2009–2010 Pandemrix vaccination programme in Sweden. J Intern Med 2015;278:335–53. doi: 10.1111/joim.12391

  6. Granath F, Gedeborg R, Smedje H, Feltelius N. Change in risk for narcolepsy over time and impact of definition of onset date following vaccination with AS03 adjuvanted pandemic A/H1N1 influenza vaccine (Pandemrix) during the 2009 H1N1 influenza pandemic. Pharmacoepidemiol Drug Saf 2019;28:1045–53. doi: 10.1002/pds.4788

  7. Wijnans L, Lecomte C, de Vries C, Weibel D, Sammon C, Hviid A, et al. The incidence of narcolepsy in Europe: before, during, and after the influenza A(H1N1)pdm09 pandemic and vaccination campaigns. Vaccine 2013;31:1246–54. doi: 10.1016/j.vaccine.2012.12.015

  8. Barker CI, Snape MD. Pandemic influenza A H1N1 vaccines and narcolepsy: vaccine safety surveillance in action. Lancet Infect Dis 2014;14:227–38. doi: 10.1016/S1473-3099(13)70238-X

  9. Chrapkowska C, Galanis I, Kark M, Lepp T, Lindstrand A, Roth A, et al. Validation of the new Swedish vaccination register – accuracy and completeness of register data. Vaccine 2020;38:4104–10. doi: 10.1016/j.vaccine.2020.04.020

  10. Rolfhamre P, Jansson A, Arneborn M, Ekdahl K. SmiNet-2: description of an internet-based surveillance system for communicable diseases in Sweden. Euro Surveill 2006;11:15–16. doi: 10.2807/esm.11.05.00626-en

  11. Ludvigsson JF, Andersson E, Ekbom A, Feychting M, Kim JL, Reuterwall C, et al. External review and validation of the Swedish national inpatient register. BMC Public Health 2011;11:450. doi: 10.1186/1471-2458-11-450

  12. The National Board of Health and Welfare, Sweden. The national patient register. Available from: [cited 23 October 2021].

  13. Barlow L, Westergren K, Holmberg L, Talbäck M. The completeness of the Swedish Cancer Register: a sample survey for year 1998. Acta Oncol 2009;48:27–33. doi: 10.1080/02841860802247664

  14. The National Board of Health and Welfare, Sweden. The cancer register. Available from: [cited 23 October 2021].

  15. Wettermark B, Hammar N, Fored CM, Leimanis A, Otterblad Olausson P, Bergman U, et al. The new Swedish Prescribed Drug Register – opportunities for pharmacoepidemiological research and experience from the first six months. Pharmacoepidemiol Drug Saf 2007;16:726–35. doi: 10.1002/pds.1294

  16. The National Board of Health and Welfare, Sweden. The Swedish prescribed drug register Available from: [cited 23 October 2021].

  17. World Health Organization (WHO) Collaborating Centre for Drug Statistics Methodology. Available from: [cited 23 October 2021].

  18. Zettersten E, Engerström L, Bell M, Jäderling G, Mårtensson J, Block L, et al. Long-term outcome after intensive care for COVID-19: differences between men and women – a nationwide cohort study. Crit Care 2021;25:86. doi: 10.1186/s13054-021-03511-x

  19. Brooke HL, Talbäck M, Hörnblad J, Johansson LA, Ludvigsson JF, Druid H, et al. The Swedish cause of death register. Eur J Epidemiol 2017;32: 765–73. doi: 10.1007/s10654-017-0316-1

  20. Ludvigsson JF, Autio G, Almqvist C, Edstedt-Bonamy AK, Ljung R, Michaelsson K, et al. Registers of the Swedish Total Population and their use in medical research. Eur J Epidemiol 2016;31:125–36. doi: 10.1007/s10654-016-0117-y

  21. Ludvigsson JF, Svedberg P, Olen O, Bruze G, Neovius M. The longitudinal integrated database for health insurance and labour market studies (LISA) and its use in medical research. Eur J Epidemiol 2019;34:423–37. doi: 10.1007/s10654-019-00511-8

  22. National Board of Health and Welfare, Sweden. In Swedish: Registret över insatser till äldre och personer med funktionsnedsättning [Register on services for elderly and persons with disability]. Available from: [cited 23 October 2021].

  23. Statistics Sweden. Reports on statistical co-ordination for the Official Statistics of Sweden. Statistics on persons with foreign background guidelines and recommendations. Örebro: SCB; 2002, p. 3. Available from: [cited 23 October 2021].

  24. Statistics Sweden. Socioekonomisk indelning (SEI) [Swedish socioeconomic classification: reports on statistical co-ordination]. Stockholm: SCB; 1982. Available from: [cited 23 October 2021].

  25. Statistics Sweden. The Swedish Standard Classification of Occupations 2012 (SSYK 2012). Available from: [cited 23 October 2021].

  26. Karolinska Institutet. Swedish Medical Subjects Heading (MeSH) – health personnel. Available from: [cited 19 September 2021].

  27. Feltelius N, Gedeborg R, Holm L, Zethelius B. Utility of registries for post-marketing evaluation of medicines. A survey of Swedish health care quality registries from a regulatory perspective. Ups J Med Sci 2017;122:136–47. doi: 10.1080/03009734.2017.1285837

  28. Ebrahim S. Cohort profiles: what are they good for? Int J Epidemiol 2021;50:367–70. doi: 10.1093/ije/dyab054

  29. The Swedish Ethical Review Authority. Available from: [cited 23 October 2021].

  30. Swedish Parliament. Lag (2003:460) om etikprövning av forskning som avser människor [In English: Act on ethical review in human research]. Available from: [cited 23 October 2021].

How to Cite
Ljung R., Sundström A., Grünewald M., Backman C., Feltelius N., Gedeborg R., & Zethelius B. (2021). The profile of the COvid-19 VACcination register SAFEty study in Sweden (CoVacSafe-SE). Upsala Journal of Medical Sciences, 126(1).
Original Articles