Background

There are limited data on the effectiveness of the vaccines against symptomatic coronavirus disease 2019 (Covid-19) currently authorized in the United States with respect to hospitalization, admission to an intensive care unit (ICU), or ambulatory care in an emergency department or urgent care clinic.

Methods

We conducted a study involving adults (≥50 years of age) with Covid-19–like illness who underwent molecular testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We assessed 41,552 admissions to 187 hospitals and 21,522 visits to 221 emergency departments or urgent care clinics during the period from January 1 through June 22, 2021, in multiple states. The patients’ vaccination status was documented in electronic health records and immunization registries. We used a test-negative design to estimate vaccine effectiveness by comparing the odds of a positive test for SARS-CoV-2 infection among vaccinated patients with those among unvaccinated patients. Vaccine effectiveness was adjusted with weights based on propensity-for-vaccination scores and according to age, geographic region, calendar time (days from January 1, 2021, to the index date for each medical visit), and local virus circulation.

Results

The effectiveness of full messenger RNA (mRNA) vaccination (≥14 days after the second dose) was 89% (95% confidence interval [CI], 87 to 91) against laboratory-confirmed SARS-CoV-2 infection leading to hospitalization, 90% (95% CI, 85 to 93) against infection leading to an ICU admission, and 91% (95% CI, 89 to 93) against infection leading to an emergency department or urgent care clinic visit. The effectiveness of full vaccination with respect to a Covid-19–associated hospitalization or emergency department or urgent care clinic visit was similar with the BNT162b2 and mRNA-1273 vaccines and ranged from 81% to 95% among adults 85 years of age or older, persons with chronic medical conditions, and Black or Hispanic adults. The effectiveness of the Ad26.COV2.S vaccine was 68% (95% CI, 50 to 79) against laboratory-confirmed SARS-CoV-2 infection leading to hospitalization and 73% (95% CI, 59 to 82) against infection leading to an emergency department or urgent care clinic visit.

Conclusions

Covid-19 vaccines in the United States were highly effective against SARS-CoV-2 infection requiring hospitalization, ICU admission, or an emergency department or urgent care clinic visit. This vaccine effectiveness extended to populations that are disproportionately affected by SARS-CoV-2 infection. (Funded by the Centers for Disease Control and Prevention.)

中文翻译：

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Covid-19 疫苗在门诊和住院护理环境中的有效性

背景

目前美国批准的针对有症状的 2019 年冠状病毒病 (Covid-19) 疫苗在住院、入住重症监护病房 (ICU) 或急诊科或急诊室的门诊护理方面的有效性数据有限。护理诊所。

方法

我们开展了一项研究，对象为患有 Covid-19 类疾病的成年人（≥50 岁），他们接受了严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 分子检测。我们评估了 2021 年 1 月 1 日至 6 月 22 日期间多个州 187 家医院的 41,552 例入院病例以及 221 个急诊科或紧急护理诊所的 21,522 例就诊病例。患者的疫苗接种状况记录在电子健康记录和免疫登记处。我们采用测试阴性设计，通过比较已接种疫苗的患者与未接种疫苗的患者中 SARS-CoV-2 感染检测呈阳性的几率来评估疫苗的有效性。疫苗有效性根据疫苗接种倾向评分以及年龄、地理区域、日历时间（从 2021 年 1 月 1 日到每次就诊索引日期的天数）和当地病毒传播情况进行权重调整。

结果

完整信使 RNA (mRNA) 疫苗接种（第二剂后≥14天）对于实验室确诊的 SARS-CoV-2 感染导致住院治疗的有效性为 89%（95% 置信区间 [CI]，87 至 91），90 %（95% CI，85 至 93）的感染导致进入 ICU，91%（95% CI，89 至 93）的感染导致急诊室或紧急护理诊所就诊。对于与 Covid-19 相关的住院、急诊科或紧急护理诊所就诊，全面接种疫苗的有效性与 BNT162b2 和 mRNA-1273 疫苗相似，在 85 岁或以上的成年人中，有效性范围为 81% 至 95%。患有慢性疾病的人以及黑人或西班牙裔成年人。Ad26.COV2.S 疫苗对导致住院的实验室确诊 SARS-CoV-2 感染的有效性为 68%（95% CI，50 至 79），对导致住院的感染的有效性为 73%（95% CI，59 至 82）。前往急诊室或紧急护理诊所就诊。

结论

美国的 Covid-19 疫苗对 SARS-CoV-2 感染非常有效，需要住院、入住 ICU、急诊科或紧急护理诊所就诊。这种疫苗的有效性扩展到了受 SARS-CoV-2 感染影响较大的人群。（由疾病控制和预防中心资助。）