First-dose ChAdOx1 and BNT162b2 COVID-19 vaccines and thrombocytopenic, thromboembolic and hemorrhagic events in Scotland

Simpson, C.R. et al. (2021) First-dose ChAdOx1 and BNT162b2 COVID-19 vaccines and thrombocytopenic, thromboembolic and hemorrhagic events in Scotland. Nature Medicine, 27(7), pp. 1290-1297. (doi: 10.1038/s41591-021-01408-4) (PMID:34108714)

[img] Text
242820.pdf - Published Version
Available under License Creative Commons Attribution.

2MB

Abstract

Reports of ChAdOx1 vaccine–associated thrombocytopenia and vascular adverse events have led to some countries restricting its use. Using a national prospective cohort, we estimated associations between exposure to first-dose ChAdOx1 or BNT162b2 vaccination and hematological and vascular adverse events using a nested incident-matched case-control study and a confirmatory self-controlled case series (SCCS) analysis. An association was found between ChAdOx1 vaccination and idiopathic thrombocytopenic purpura (ITP) (0–27 d after vaccination; adjusted rate ratio (aRR) = 5.77, 95% confidence interval (CI), 2.41–13.83), with an estimated incidence of 1.13 (0.62–1.63) cases per 100,000 doses. An SCCS analysis confirmed that this was unlikely due to bias (RR = 1.98 (1.29–3.02)). There was also an increased risk for arterial thromboembolic events (aRR = 1.22, 1.12–1.34) 0–27 d after vaccination, with an SCCS RR of 0.97 (0.93–1.02). For hemorrhagic events 0–27 d after vaccination, the aRR was 1.48 (1.12–1.96), with an SCCS RR of 0.95 (0.82–1.11). A first dose of ChAdOx1 was found to be associated with small increased risks of ITP, with suggestive evidence of an increased risk of arterial thromboembolic and hemorrhagic events. The attenuation of effect found in the SCCS analysis means that there is the potential for overestimation of the reported results, which might indicate the presence of some residual confounding or confounding by indication. Public health authorities should inform their jurisdictions of these relatively small increased risks associated with ChAdOx1. No positive associations were seen between BNT162b2 and thrombocytopenic, thromboembolic and hemorrhagic events.

Item Type:Articles
Additional Information:EAVE II is funded by the Medical Research Council (MC_PC_19075) with the support of BREATHE: the Health Data Research Hub for Respiratory Health (MC_PC_19004), which is funded through the UK Research and Innovation Industrial Strategy Challenge Fund and delivered through Health Data Research UK. Additional support has been provided through Public Health Scotland and the Community Health and Social Care Directorate of the Scottish Government. R.H. acknowledges support from the National Institute for Health Research (NIHR) School for Primary Care Research, the NIHR Collaboration for Leadership in Applied Health Research and Care Oxford and the NIHR Oxford BREATHE Centre.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Katikireddi, Professor Vittal and Mccowan, Professor Colin
Authors: Simpson, C.R., Shi, T., Vasileiou, E., Katikireddi, S.V., Kerr, S., Moore, E., McCowan, C., Agrawal, U., Shah, S.A., Ritchie, L.D., Murray, J., Pan, J., Bradley, D.T., Stock, S.J., Wood, R., Chuter, A., Beggs, J., Stagg, H., Joy, M., Tsang, R.S.M., de Lusignan, S., Hobbs, R., Lyons, R.A., Torabi, F., Bedston, S., O’Leary, M., Akbari, A., McMenamin, J., Robertson, C., and Sheikh, A.
College/School:College of Medical Veterinary and Life Sciences > Institute of Health and Wellbeing > MRC/CSO SPHSU
Journal Name:Nature Medicine
Publisher:Nature Research
ISSN:1078-8956
ISSN (Online):1546-170X
Published Online:09 June 2021
Copyright Holders:Copyright © 2021 The Authors
First Published:First published in Nature Medicine 27(7): 1290-1297
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record