Objective To assess the association between covid-19 vaccines and risk of thrombocytopenia and thromboembolic events in England among adults. Design Self-controlled case series study using national data on covid-19 vaccination and hospital admissions. Setting Patient level data were obtained for approximately 30 million people vaccinated in England between 1 December 2020 and 24 April 2021. Electronic health records were linked with death data from the Office for National Statistics, SARS-CoV-2 positive test data, and hospital admission data from the United Kingdom’s health service (NHS). Participants 29 121 633 people were vaccinated with first doses (19 608 008 with Oxford-AstraZeneca (ChAdOx1 nCoV-19) and 9 513 625 with Pfizer-BioNTech (BNT162b2 mRNA)) and 1 758 095 people had a positive SARS-CoV-2 test. People aged ≥16 years who had first doses of the ChAdOx1 nCoV-19 or BNT162b2 mRNA vaccines and any outcome of interest were included in the study. Main outcome measures The primary outcomes were hospital admission or death associated with thrombocytopenia, venous thromboembolism, and arterial thromboembolism within 28 days of three exposures: first dose of the ChAdOx1 nCoV-19 vaccine; first dose of the BNT162b2 mRNA vaccine; and a SARS-CoV-2 positive test. Secondary outcomes were subsets of the primary outcomes: cerebral venous sinus thrombosis (CVST), ischaemic stroke, myocardial infarction, and other rare arterial thrombotic events. Results The study found increased risk of thrombocytopenia after ChAdOx1 nCoV-19 vaccination (incidence rate ratio 1.33, 95% confidence interval 1.19 to 1.47 at 8-14 days) and after a positive SARS-CoV-2 test (5.27, 4.34 to 6.40 at 8-14 days); increased risk of venous thromboembolism after ChAdOx1 nCoV-19 vaccination (1.10, 1.02 to 1.18 at 8-14 days) and after SARS-CoV-2 infection (13.86, 12.76 to 15.05 at 8-14 days); and increased risk of arterial thromboembolism after BNT162b2 mRNA vaccination (1.06, 1.01 to 1.10 at 15-21 days) and after SARS-CoV-2 infection (2.02, 1.82 to 2.24 at 15-21 days). Secondary analyses found increased risk of CVST after ChAdOx1 nCoV-19 vaccination (4.01, 2.08 to 7.71 at 8-14 days), after BNT162b2 mRNA vaccination (3.58, 1.39 to 9.27 at 15-21 days), and after a positive SARS-CoV-2 test; increased risk of ischaemic stroke after BNT162b2 mRNA vaccination (1.12, 1.04 to 1.20 at 15-21 days) and after a positive SARS-CoV-2 test; and increased risk of other rare arterial thrombotic events after ChAdOx1 nCoV-19 vaccination (1.21, 1.02 to 1.43 at 8-14 days) and after a positive SARS-CoV-2 test. Conclusion Increased risks of haematological and vascular events that led to hospital admission or death were observed for short time intervals after first doses of the ChAdOx1 nCoV-19 and BNT162b2 mRNA vaccines. The risks of most of these events were substantially higher and more prolonged after SARS-CoV-2 infection than after vaccination in the same population. To guarantee the confidentiality of personal and health information only the authors have had access to the data during the study in accordance with the relevant licence agreements.

中文翻译：

---

covid-19 疫苗接种和 SARS-CoV-2 阳性检测后血小板减少和血栓栓塞的风险：自我对照病例系列研究


目的 评估英国成人中新冠肺炎 (covid-19) 疫苗与血小板减少症和血栓栓塞事件风险之间的关联。使用有关 covid-19 疫苗接种和住院情况的国家数据设计自我对照病例系列研究。设置 获得了 2020 年 12 月 1 日至 2021 年 4 月 24 日期间英格兰约 3000 万人接种疫苗的患者水平数据。电子健康记录与国家统计办公室的死亡数据、SARS-CoV-2 阳性检测数据和入院数据相关联数据来自英国医疗服务体系（NHS）。参与者 29 121 633 人接种了第一剂疫苗（19 608 008 人接种了牛津-阿斯利康 (ChAdOx1 nCoV-19) 疫苗，9 513 625 人接种了辉瑞 BioNTech (BNT162b2 mRNA) 疫苗），1 758 095 人的 SARS-CoV-2 呈阳性测试。该研究纳入了首次接种 ChAdOx1 nCoV-19 或 BNT162b2 mRNA 疫苗且年龄≥16 岁的人以及任何感兴趣的结果。主要结局指标主要结局是在 3 次暴露后 28 天内因血小板减少症、静脉血栓栓塞和动脉血栓栓塞相关的入院或死亡：第一剂 ChAdOx1 nCoV-19 疫苗；第一剂 BNT162b2 mRNA 疫苗； SARS-CoV-2 检测呈阳性。次要结局是主要结局的子集：脑静脉窦血栓形成（CVST）、缺血性中风、心肌梗死和其他罕见的动脉血栓事件。结果 研究发现，接种 ChAdOx1 nCoV-19 疫苗后（第 8-14 天的发病率比为 1.33，95% 置信区间为 1.19 至 1.47）以及 SARS-CoV-2 检测呈阳性（第 8-14 天为 5.27、4.34 至 6.40）后，血小板减少症的风险增加。 8-14天）； ChAdOx1 nCoV-19 疫苗接种后静脉血栓栓塞的风险增加（1.10、1.02 至 1.18 8-14 天）和 SARS-CoV-2 感染后（8-14 天 13.86、12.76 至 15.05）； BNT162b2 mRNA 疫苗接种后（15-21 天为 1.06、1.01 至 1.10）和 SARS-CoV-2 感染后（15-21 天为 2.02、1.82 至 2.24）动脉血栓栓塞风险增加。二次分析发现，ChAdOx1 nCoV-19 疫苗接种后（8-14 天为 4.01、2.08 至 7.71）、BNT162b2 mRNA 疫苗接种后（15-21 天为 3.58、1.39 至 9.27）以及 SARS-CoV 阳性后，CVST 风险增加-2测试； BNT162b2 mRNA 疫苗接种后（15-21 天为 1.12、1.04 至 1.20）和 SARS-CoV-2 检测呈阳性后，缺血性中风的风险增加； ChAdOx1 nCoV-19 疫苗接种后（8-14 天为 1.21、1.02 至 1.43）和 SARS-CoV-2 检测呈阳性后，其他罕见动脉血栓事件的风险增加。结论 在首次接种 ChAdOx1 nCoV-19 和 BNT162b2 mRNA 疫苗后，在短时间内观察到导致入院或死亡的血液学和血管事件风险增加。在同一人群中，与接种疫苗后相比，感染 SARS-CoV-2 后大多数事件的风险要高得多且持续时间更长。为了保证个人和健康信息的机密性，只有作者根据相关许可协议才能在研究期间访问数据。