You are here

Article Text

Article menu
Infectious diseases
Original research
SARS-CoV-2 vaccination, ABO blood group and risk of COVID-19: population-based cohort study
  1. Joel G Ray1,2,
  2. Alison L Park2
  1. 1Medicine, St. Michael's Hospital, Toronto, Ontario, Canada
  2. 2ICES, Toronto, Ontario, Canada
  1. Correspondence to Dr Joel G Ray; RayJ{at}smh.ca

Abstract

Objective To compare outcomes between O and non-O blood groups, and by modified RNA (mRNA) and adenovirus-vectored (Ad-V) vaccines.

Design Population-based cohort study.

Setting All of Ontario, Canada. Linked data sets captured clinical encounters, vaccinations and laboratory testing for SARS-CoV-2.

Participants Individuals aged 12+ years with known ABO blood group and free of SARS-CoV-2 before 15 January 2021.

Main outcomes measures The main exposure, first SARS-CoV-2 vaccination, was modelled in a time-varying manner. O and non-O blood group was known prior to vaccination. SARS-CoV-2 infection, and severe COVID-19 (hospitalisation or death), were assessed starting 14 days after vaccination, up to 27 June 2021.

Results 2 472 261 individuals were included. 1 743 916 (70.5%) had at least one vaccination, of which 24.6% were fully vaccinated. Those vaccinated were more likely to be women, older in age, residing in a higher-income area and have higher rates of certain comorbid conditions, like cancer, diabetes and hypertension. Relative to unvaccinated, after receiving their first mRNA (adjusted HR (aHR) 0.46, 95% CI 0.44 to 0.47) or Ad-V (aHR 0.49, 95% CI 0.44 to 0.54) vaccine, the risk of SARS-CoV-2 infection was lower, as was severe COVID-19 (aHR 0.29, 95% CI 0.20 to 0.43 (mRNA); aHR 0.29, 95% CI 0.26 to 0.33 (Ad-V)). Stratifying by blood group produced similar results. For example, after first mRNA vaccination, the aHR of severe COVID-19 was 0.31 (95% CI 0.27 to 0.36) among non-O blood groups, and 0.27 (95% CI 0.22 to 0.32) among O blood groups, relative to unvaccinated. Fully vaccinated individuals had the lowest risk of SARS-CoV-2 and severe COVID-19.

Conclusions SARS-CoV-2 infection and severe COVID-19 are reduced by vaccination. This effect does not vary by vaccine type or blood group, but is more pronounced among fully, than partially, vaccinated individuals.

  • HAEMATOLOGY
  • INFECTIOUS DISEASES
  • Epidemiology
  • COVID-19
  • Blood bank & transfusion medicine

Data availability statement

No data are available. No additional data available.

http://creativecommons.org/licenses/by-nc/4.0/

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

https://doi-org.ezproxy.u-pec.fr/10.1136/bmjopen-2021-059944

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Data availability statement

    No data are available. No additional data available.

    View Full Text

    Supplementary materials

    • Supplementary Data

      This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

    Footnotes

    • Contributors JR and ALP: Study concept, analysis and interpretation of the data, drafting of manuscript, manuscript revision and approval of final version.

    • Funding Funded by a grant from the Ontario Academic Health Sciences Centre AFP Innovation Fund, and the Ontario Ministry of Health (MOH).This study was also supported by ICES, which is funded by an annual grant from the Ontario MOH and the Ministry of Long-Term Care. Parts of this material are based on data and information compiled and provided by MOH and the Canadian Institute for Health Information.

    • Disclaimer The analyses, conclusions, opinions and statements expressed herein are solely those of the authors and do not reflect those of the funding or data sources; no endorsement is intended or should be inferred.

    • Competing interests None declared.

    • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.