Background

Mass indoor gatherings were banned in early 2020 to prevent the spread of SARS-CoV-2. We aimed to assess, under controlled conditions, whether infection rates among attendees at a large, indoor gathering event would be similar to those in non-attendees, given implementation of a comprehensive prevention strategy including antigen-screening within 3 days, medical mask wearing, and optimised ventilation.

Methods

The non-inferiority, prospective, open-label, randomised, controlled SPRING trial was done on attendees at a live indoor concert held in the Accor Arena on May 29, 2021 in Paris, France. Participants, aged 18–45 years, recruited via a dedicated website, had no comorbidities, COVID-19 symptoms, or recent case contact, and had had a negative rapid antigen diagnostic test within 3 days before the concert. Participants were randomly allocated in a 2:1 ratio to the experimental group (attendees) or to the control group (non-attendees). The allocation sequence was computer-generated by means of permuted blocks of sizes three, six, or nine, with no stratification. The primary outcome measure was the number of patients who were SARS-CoV-2-positive by RT-PCR test on self-collected saliva 7 days post-gathering in the per-protocol population (non-inferiority margin <0·35%). This trial is registered with ClinicalTrials.gov, NCT04872075.

Findings

Between May 11 and 25, 2021, 18 845 individuals registered on the dedicated website, and 10 953 were randomly selected for a pre-enrolment on-site visit. Among 6968 who kept the appointment and were screened, 6678 participants were randomly assigned (4451 were assigned to be attendees and 2227 to be non-attendees; median age 28 years; 59% women); 88% (3917) of attendees and 87% (1947) of non-attendees complied with follow-up requirements. The day 7 RT-PCR was positive for eight of the 3917 attendees (observed incidence, 0·20%; 95% CI 0·09–0·40) and three of the 1947 non-attendees (0·15%; 0·03–0·45; absolute difference, 95% CI −0·26% to 0·28%), findings that met the non-inferiority criterion for the primary endpoint.

Interpretation

Participation in a large, indoor, live gathering without physical distancing was not associated with increased SARS-CoV-2–transmission risk, provided a comprehensive preventive intervention was implemented.

Funding

French Ministry of Health.

Translation

For the French translation of the abstract see Supplementary Materials section.

中文翻译：

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在大型现场室内聚会 (SPRING) 期间预防 SARS-CoV-2 传播：一项非劣效性、随机、对照试验

 背景

2020 年初禁止大规模室内聚会，以防止 SARS-CoV-2 的传播。我们的目的是评估在受控条件下，考虑到实施包括 3 天内抗原筛查、佩戴医用口罩、并优化通风。

 方法

这项非劣效性、前瞻性、开放标签、随机、对照 SPRING 试验是在 2021 年 5 月 29 日在法国巴黎雅高体育馆举行的现场室内音乐会的参加者身上进行的。参与者年龄在 18 至 45 岁之间，通过专门网站招募，没有合并症、COVID-19 症状或近期接触过病例，并且在音乐会前 3 天内进行过快速抗原诊断测试，结果呈阴性。参与者以 2:1 的比例随机分配到实验组（参加者）或对照组（未参加者）。分配序列是计算机通过大小为 3、6 或 9 的排列块生成的，没有分层。主要结局指标是按方案人群中采集后 7 天的自体唾液 RT-PCR 测试显示 SARS-CoV-2 阳性的患者人数（非劣效性界值 <0·35%） 。该试验已在 ClinicalTrials.gov 注册，NCT04872075。

 发现

2021年5月11日至25日期间，共有18 845人在专门网站上注册，并随机抽取10 953人进行预登记现场访问。在 6968 名预约并接受筛查的参与者中，6678 名参与者被随机分配（4451 名被分配为参加者，2227 名被分配为非参加者；中位年龄 28 岁；59% 为女性）； 88% (3917) 的与会者和 87% (1947) 的未与会者遵守了后续要求。第 7 天，3917 名参加者中的 8 名（观察发生率，0·20%；95% CI 0·09–0·40）和 1947 名未参加者中的 3 名（0·15%；0·40）的 RT-PCR 呈阳性。 03–0·45；绝对差异，95% CI -0·26% 至 0·28%），结果符合主要终点的非劣效性标准。

 解释

如果实施了全面的预防干预措施，参加没有保持身体距离的大型室内现场聚会与 SARS-CoV-2 传播风险增加无关。

 资金

法国卫生部。

 翻译

有关摘要的法文翻译，请参阅补充材料部分。