ABSTRACT

Data regarding protection against mortality and severe complications after Omicron BA.2 infection with CoronaVac and BNT162b2 vaccines remains limited. We conducted a case–control study to evaluate the risk of severe complications and mortality following 1–3 doses of CoronaVac and BNT162b2 using electronic health records database. Cases were adults with their first COVID-19-related mortality or severe complications between 1 January and 31 March 2022, matched with up-to 10 controls by age, sex, index date, and Charlson Comorbidity Index. Vaccine effectiveness against COVID-19-related mortality and severe complications by type and number of doses was estimated using conditional logistic regression adjusted for comorbidities and medications. Vaccine effectiveness (95% CI) against COVID-19-related mortality after two doses of BNT162b2 and CoronaVac were 90.7% (88.6–92.3) and 74.8% (72.5–76.9) in those aged ≥65, 87.6% (81.4–91.8) and 80.7% (72.8–86.3) in those aged 50–64, 86.6% (71.0–93.8) and 82.7% (56.5–93.1) in those aged 18–50. Vaccine effectiveness against severe complications after two doses of BNT162b2 and CoronaVac were 82.1% (74.6–87.3) and 58.9% (50.3–66.1) in those aged ≥65, 83.0% (69.6–90.5) and 67.1% (47.1–79.6) in those aged 50–64, 78.3% (60.8–88.0) and 77.8% (49.6–90.2) in those aged 18–50. Further risk reduction with the third dose was observed especially in those aged ≥65 years, with vaccine effectiveness of 98.0% (96.5–98.9) for BNT162b2 and 95.5% (93.7–96.8) for CoronaVac against mortality, 90.8% (83.4–94.9) and 88.0% (80.8–92.5) against severe complications. Both CoronaVac and BNT162b2 vaccination were effective against COVID-19-related mortality and severe complications amidst the Omicron BA.2 pandemic, and risks decreased further with the third dose.

摘要

关于用 CoronaVac 和 BNT162b2 疫苗感染 Omicron BA.2 后预防死亡和严重并发症的数据仍然有限。我们进行了一项病例对照研究，以使用电子健康记录数据库评估 1-3 剂 CoronaVac 和 BNT162b2 后严重并发症和死亡的风险。病例是在 2022 年 1 月 1 日至 3 月 31 日期间首次出现与 COVID-19 相关的死亡或严重并发症的成年人，并按年龄、性别、索引日期和 Charlson 合并症指数与多达 10 名对照匹配。使用针对合并症和药物调整的条件逻辑回归估计疫苗对 COVID-19 相关死亡率和严重并发症的类型和剂量数量的有效性。在 ≥65 岁的人群中，接种两剂 BNT162b2 和 CoronaVac 后疫苗对 COVID-19 相关死亡率的有效性（95% CI）分别为 90.7%（88.6-92.3）和 74.8%（72.5-76.9），87.6%（81.4-91.8） 80.7%（72.8-86.3）在 50-64 岁人群中，86.6%（71.0-93.8）和 82.7%（56.5-93.1）在 18-50 岁人群中。接种两剂 BNT162b2 和 CoronaVac 后，疫苗对严重并发症的有效性在≥65 岁的人群中分别为 82.1% (74.6–87.3) 和 58.9% (50.3–66.1)，在 65 岁以上的人群中分别为 83.0% (69.6–90.5) 和 67.1% (47.1–79.6) 50-64 岁，78.3% (60.8-88.0) 和 77.8% (49.6-90.2) 在 18-50 岁。观察到第三剂疫苗的风险进一步降低，特别是在 65 岁以上的人群中，BNT162b2 的疫苗有效性为 98.0% (96.5–98.9)，CoronaVac 的疫苗有效性为 95.5% (93.7–96.8)，死亡率为 90.8% (83.4–94.9)和 88.0% (80.8–92.5) 对严重并发症。