Emerg Infect Dis. 2021 May;27(5):1343-1352. doi: 10.3201/eid2705.204365.
We investigated what proportion of the population acquired severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and whether the herd immunity threshold has been reached in 10 communities in Qatar. The study included 4,970 participants during June 21-September 9, 2020. Antibodies against SARS-CoV-2 were detected by using an electrochemiluminescence immunoassay. Seropositivity ranged from 54.9% (95% CI 50.2%-59.4%) to 83.8% (95% CI 79.1%-87.7%) across communities and showed a pooled mean of 66.1% (95% CI 61.5%-70.6%). A range of other epidemiologic measures indicated that active infection is rare, with limited if any sustainable infection transmission for clusters to occur. Only 5 infections were ever severe and 1 was critical in these young communities; infection severity rate of 0.2% (95% CI 0.1%-0.4%). Specific communities in Qatar have or nearly reached herd immunity for SARS-CoV-2 infection: 65%-70% of the population has been infected.
我们调查了卡塔尔 10 个社区中有多少人口感染了严重急性呼吸综合征冠状病毒 2（SARS-CoV-2），以及群体免疫阈值是否已经达到。该研究包括 2020 年 6 月 21 日至 9 月 9 日期间的 4970 名参与者。使用电化学发光免疫分析法检测 SARS-CoV-2 抗体。血清阳性率在社区之间从 54.9%（95%CI 50.2%-59.4%）到 83.8%（95%CI 79.1%-87.7%）不等，平均为 66.1%（95%CI 61.5%-70.6%）。一系列其他流行病学指标表明，活跃感染很少见，集群发生任何可持续的感染传播的可能性都很有限。在这些年轻的社区中，仅有 5 例感染是严重的，其中 1 例是危急的；感染严重率为 0.2%（95%CI 0.1%-0.4%）。卡塔尔的一些特定社区已经或几乎达到了 SARS-CoV-2 感染的群体免疫水平：65%-70%的人口已经感染。
