接种COVID-19疫苗可降低感染相关死亡率。不幸的是,疫苗诱导的免疫血栓性血小板减少症(VITT)在个体施用腺病毒载体疫苗(ChAdOx1nCoV-19和Ad26。COV2.S)引发了副作用的担忧。为了解决与此相关的疫苗犹豫,在接受两剂基于mRNA的COVID-19疫苗接种的患者中,必须确定VITT的发生率(定义为疫苗接种后4-28天内血小板计数减少50%和抗PF4免疫测定阳性).我们确定了克利夫兰诊所企业的223,345名患者的回顾性队列,从2020年12月4日至2021年6月6日在俄亥俄州东北部和佛罗里达州的任何地点接种了COVID-19疫苗。这些患者中有97.3%接受了基于mRNA的疫苗接种。选择以下患者:(1)疫苗接种前后的连续全血细胞计数以及(2)血小板计数降低≥50%的患者进行图表审查。主要结果是血栓事件的发生率,包括静脉血栓栓塞(VTE)和动脉血栓形成,疫苗接种后4-28天。在74例急性血栓形成的队列患者中,72(97.3%)病因明确,如活动性恶性肿瘤。在两名无缘无故的血栓形成患者中,只有一个有关于VITT的调查结果,用强阳性抗PF4抗体测定。在这个大的,多状态,回顾性队列,223,345名患者(其中97.2%接受了基于mRNA的mRNA-1273或BNT162b2疫苗),我们在接受mRNA疫苗的患者中检测到一例与VITT相关的病例.绝大多数在接种疫苗后4-28天出现血栓形成事件的患者表现出明确的病因。
Vaccination against COVID-19 reduces infection-related mortality. Unfortunately, reports of vaccine-induced immune thrombotic thrombocytopenia (VITT) in individuals administered adenovirus-vector-based vaccines (ChAdOx1 nCoV-19 and Ad26.COV2.S) have spurred side effect concerns. To address vaccine hesitancy related to this, it is essential to determine the incidence of VITT (defined by a 50% decrease in platelet count and positive anti-PF4 immunoassay within 4-28 days after vaccination) among patients administered two doses of an mRNA-based COVID-19 vaccination. We identified a retrospective cohort of 223,345 patients in the Cleveland Clinic Enterprise administered a COVID-19 vaccine at any location in Northeast Ohio and Florida from 12/4/2020 to 6/6/2021. 97.3% of these patients received an mRNA-based vaccination. Patients with: (1) a serial complete blood count both before and after vaccination and (2) a decrease in platelet count of ≥ 50% were selected for chart review. The primary outcome was the incidence of thrombotic events, including venous thromboembolism (VTE) and arterial thrombosis, 4-28 days post vaccination. Of 74 cohort patients with acute thrombosis, 72 (97.3%) demonstrated clear etiologies, such as active malignancy. Of two patients with unprovoked thrombosis, only one had findings concerning for VITT, with a strongly positive anti-PF4 antibody assay. In this large, multi-state, retrospective cohort, of 223,345 patients (97.2% of whom received the mRNA-based mRNA-1273 or BNT162b2 vaccines), we detected a single case that was concerning for VITT in a patient who received an mRNA vaccine. The overwhelming majority of patients with a thrombotic event 4-28 days following vaccination demonstrated clear etiologies.