Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA.
Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Clin Infect Dis. 2021 Nov 16;73(10):1882-1886. doi: 10.1093/cid/ciab234.
Protection afforded from prior disease among patients with coronavirus disease 2019 (COVID-19) infection is unknown. If infection provides substantial long-lasting immunity, it may be appropriate to reconsider vaccination distribution.
This retrospective cohort study of 1 health system included 150 325 patients tested for COVID-19 infection via polymerase chain reaction from 12 March 2020 to 30 August 2020. Testing performed up to 24 February 2021 in these patients was included. The main outcome was reinfection, defined as infection ≥90 days after initial testing. Secondary outcomes were symptomatic infection and protection of prior infection against reinfection.
Of 150 325 patients, 8845 (5.9%) tested positive and 141 480 (94.1%) tested negative before 30 August. A total of 1278 (14.4%) positive patients were retested after 90 days, and 62 had possible reinfection. Of those, 31 (50%) were symptomatic. Of those with initial negative testing, 5449 (3.9%) were subsequently positive and 3191 of those (58.5%) were symptomatic. Protection offered from prior infection was 81.8% (95% confidence interval [CI], 76.6-85.8) and against symptomatic infection was 84.5% (95% CI, 77.9-89.1). This protection increased over time.
Prior infection in patients with COVID-19 was highly protective against reinfection and symptomatic disease. This protection increased over time, suggesting that viral shedding or ongoing immune response may persist beyond 90 days and may not represent true reinfection. As vaccine supply is limited, patients with known history of COVID-19 could delay early vaccination to allow for the most vulnerable to access the vaccine and slow transmission.
新型冠状病毒疾病 2019（COVID-19）感染者既往疾病提供的保护尚不清楚。如果感染提供了大量持久的免疫力，那么重新考虑疫苗接种分布可能是合适的。
这项回顾性队列研究纳入了一个医疗系统的 150325 例患者，这些患者在 2020 年 3 月 12 日至 2020 年 8 月 30 日期间通过聚合酶链反应检测 COVID-19 感染。在这些患者中，截至 2021 年 2 月 24 日进行的检测均包括在内。主要结局是再感染，定义为初次检测后 90 天以上的感染。次要结局是症状性感染和既往感染对再感染的保护作用。
在 150325 例患者中，8845 例（5.9%）检测结果为阳性，141480 例（94.1%）在 8 月 30 日之前检测结果为阴性。共有 1278 例（14.4%）阳性患者在 90 天后接受了再次检测，其中 62 例可能发生了再感染。其中，31 例（50%）出现症状。在最初检测结果为阴性的患者中，5449 例（3.9%）随后转为阳性，其中 3191 例（58.5%）出现症状。既往感染的保护率为 81.8%（95%置信区间[CI]，76.6-85.8），对症状性感染的保护率为 84.5%（95%CI，77.9-89.1）。这种保护作用随着时间的推移而增加。
COVID-19 患者既往感染对再感染和症状性疾病有高度保护作用。这种保护作用随着时间的推移而增加，这表明病毒脱落或持续的免疫反应可能持续 90 天以上，且可能不是真正的再感染。由于疫苗供应有限，有已知 COVID-19 病史的患者可以推迟早期接种疫苗，以使最脆弱的人群能够获得疫苗，并减缓传播。
