Association of COVID-19 vaccines ChAdOx1 and BNT162b2 with major venous, arterial, or thrombocytopenic events: A population-based cohort study of 46 million adults in England

• DOI: 10.1371/journal.pmed.1003926
• Publication Date: 2022-02-22T18:25:22Z
• Authors: William N. Whiteley; Samantha Ip; Jennifer A. Cooper; Thomas Bolton; Spencer Keene; Venexia Walker; Rachel Denholm; Ashley Akbari; Efosa Omigie; Sam Hollings; Emanuele Di Angel...; Spiros Denaxas; Angela Wood; Jonathan A. C. St...; Cathie Sudlow
• Keywords: Stroke

Thromboses in unusual locations after the Coronavirus Disease 2019 (COVID-19) vaccine ChAdOx1-S have been reported, although their frequency with vaccines of different types is uncertain at a population level. The aim this study was to estimate population-level risks hospitalised thrombocytopenia and major arterial venous thromboses COVID-19 vaccination.In whole-population cohort study, we analysed linked electronic health records from adults living England, 8 December 2020 18 March 2021. We estimated incidence rates hazard ratios (HRs) for arterial, venous, thrombocytopenic outcomes 1 28 >28 days first vaccination dose BNT162b2 vaccines. Analyses were performed separately ages <70 ≥70 years adjusted age, age2, sex, ethnicity, deprivation. also prespecified adjustment anticoagulant medication, combined oral contraceptive hormone replacement therapy history pulmonary embolism or deep vein thrombosis, coronavirus infection analyses thrombosis; diabetes, hypertension, smoking, antiplatelet blood pressure lowering lipid stroke, myocardial infarction thromboses. selected further covariates backward selection. Of 46 million adults, 23 (51%) women; 39 (84%) <70; 3.7 (8.1%) Asian British, 1.6 (3.5%) Black 36 (79%) White, 0.7 (1.5%) mixed 1.5 (3.2%) another ethnicity. Approximately 21 (46%) had between crude (per 100,000 person-years) all events as follows: prevaccination, 140 [95% confidence interval (CI): 138 142]; ≤28 post-ChAdOx1-S, 294 (281 307); 359 (338 382), post-BNT162b2-S, 241 (229 253); post-BNT162b2-S 277 (263 291). 546 (95% CI: 541 555); 1,211 (1,185 1,237); 1678 (1,630 1,726), 1,242 (1,214 1,269); 1,539 (1,507 1,572). Adjusted HRs (aHRs) ChAdOx1-S, compared unvaccinated rates, years, respectively, 0.97 0.90 1.05) 0.58 (0.53 0.63) thromboses, (0.86 0.95) 0.76 (0.73 0.79) Corresponding aHRs 0.81 (0.74 0.88) 0.57 0.62) 0.94 (0.90 0.99) 0.72 (0.70 0.75) thrombotic higher younger both Rates intracranial thrombosis (ICVT) aged (aHRs 2.27, 95% 1.33 3.88 1.71, 1.35 2.16, respectively), but not (0.59, 0.24 1.45 1.00, 0.75 1.34) unvaccinated. corresponding absolute excess ICVT 0.9 3 per million, varying by age sex. main limitations are (i) it relies on accuracy coded healthcare data identify exposures, covariates, outcomes; (ii) use primary reason hospital admission measure outcome, which improves positive predictive value may lead an underestimation incidence; (iii) potential unmeasured confounding.In observed increases that small its effect reducing morbidity mortality, more precise estimates <40 needed. For people generally lower either unvaccinated, suggesting suitable group.