Objective To estimate the effectiveness of mRNA vaccines against moderate and severe covid-19 in adults by time since second, third, or fourth doses, and by age and immunocompromised status. Design Test negative case-control study. Setting Hospitals, emergency departments, and urgent care clinics in 10 US states, 17 January 2021 to 12 July 2022. Participants 893 461 adults (≥18 years) admitted to one of 261 hospitals or to one of 272 emergency department or 119 urgent care centers for covid-like illness tested for SARS-CoV-2. Main outcome measures The main outcome was waning of vaccine effectiveness with BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine during the omicron and delta periods, and the period before delta was dominant using logistic regression conditioned on calendar week and geographic area while adjusting for age, race, ethnicity, local virus circulation, immunocompromised status, and likelihood of being vaccinated. Results 45 903 people admitted to hospital with covid-19 (cases) were compared with 213 103 people with covid-like illness who tested negative for SARS-CoV-2 (controls), and 103 287 people admitted to emergency department or urgent care with covid-19 (cases) were compared with 531 168 people with covid-like illness who tested negative for SARS-CoV-2. In the omicron period, vaccine effectiveness against covid-19 requiring admission to hospital was 89% (95% confidence interval 88% to 90%) within two months after dose 3 but waned to 66% (63% to 68%) by four to five months. Vaccine effectiveness of three doses against emergency department or urgent care visits was 83% (82% to 84%) initially but waned to 46% (44% to 49%) by four to five months. Waning was evident in all subgroups, including young adults and individuals who were not immunocompromised; although waning was morein people who were immunocompromised. Vaccine effectiveness increased among most groups after a fourth dose in whom this booster was recommended. Conclusions Effectiveness of mRNA vaccines against moderate and severe covid-19 waned with time after vaccination. The findings support recommendations for a booster dose after a primary series and consideration of additional booster doses. No additional data available.

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来自 VISION 网络的美国成年人对中度和重度 covid-19 的疫苗有效性减弱：测试阴性病例对照研究

目的 评估 mRNA 疫苗对成人中度和重度 covid-19 的有效性，按从第二剂、第三剂或第四剂起的时间以及年龄和免疫功能低下状态进行评估。设计测试阴性病例对照研究。2021 年 1 月 17 日至 2022 年 7 月 12 日在美国 10 个州设置医院、急诊科和紧急护理诊所。参与者 893 461 名成人（≥18 岁）入住 261 家医院之一或 272 家急诊科或 119 家紧急护理中心之一用于检测 SARS-CoV-2 的类似 covid 的疾病。主要结果测量 主要结果是在 omicron 和 delta 期间使用 BNT162b2 (Pfizer-BioNTech) 或 mRNA-1273 (Moderna) 疫苗的疫苗有效性减弱，并且使用基于日历周和地理区域的逻辑回归，delta 之前的时期占主导地位在调整年龄、种族、种族、当地病毒传播、免疫功能低下状态和接种疫苗的可能性。结果 45 903 名因 COVID-19 入院的人（病例）与 213 103 名因 SARS-CoV-2 检测呈阴性的 COVID 样疾病患者（对照组）和 103 287 名因感染 COVID-19 入院的急诊科或紧急护理人员进行了比较covid-19（病例）与 531,168 名 SARS-CoV-2 检测呈阴性的 covid 样疾病患者进行了比较。在 omicron 期间，需要住院的 covid-19 疫苗的有效性在第 3 剂后两个月内为 89%（95% 置信区间为 88% 至 90%），但在第 3 剂后下降至 66%（63% 至 68%）。五个月。三剂疫苗对急诊科或急诊就诊的有效性最初为 83%（82% 至 84%），但在 4 至 5 个月后下降至 46%（44% 至 49%）。所有亚组均明显减弱，包括年轻人和未免疫功能低下的个体；虽然在免疫功能低下的人中减弱更多。在推荐该加强剂的第四剂之后，大多数组的疫苗有效性增加。结论 mRNA 疫苗对中度和重度 covid-19 的有效性在接种疫苗后随着时间的推移而减弱。研究结果支持在主要系列后加强剂量的建议和考虑额外加强剂量的建议。没有可用的额外数据。结论 mRNA 疫苗对中度和重度 covid-19 的有效性在接种疫苗后随着时间的推移而减弱。研究结果支持在主要系列后加强剂量的建议和考虑额外加强剂量的建议。没有可用的额外数据。结论 mRNA 疫苗对中度和重度 covid-19 的有效性在接种疫苗后随着时间的推移而减弱。研究结果支持在主要系列后加强剂量的建议和考虑额外加强剂量的建议。没有可用的额外数据。