Soni Apurv, Herbert Carly, Filippaios Andreas, Broach John, Colubri Andres, Fahey Nisha, Woods Kelsey, Nanavati Janvi, Wright Colton, Orwig Taylor, Gilliam Karen, Kheterpal Vik, Suvarna Thejas, Nowak Chris, Schrader Summer, Lin Honghuang, O'Connor Laurel, Pretz Caitlin, Ayturk Didem, Orvek Elizabeth, Flahive Julie, Lazar Peter, Shi Qiming, Achenbach Chad, Murphy Robert, Robinson Matthew, Gibson Laura, Stamegna Pamela, Hafer Nathaniel, Luzuriaga Katherine, Barton Bruce, Heetderks William, Manabe Yukari C, McManus David
medRxiv. 2022 Mar 2:2022.02.27.22271090. doi: 10.1101/2022.02.27.22271090.
There is a need to understand the performance of rapid antigen tests (Ag-RDT) for detection of the Delta (B.1.61.7; AY.X) and Omicron (B.1.1.529; BA1) SARS-CoV-2 variants.
Participants without any symptoms were enrolled from October 18, 2021 to January 24, 2022 and performed Ag-RDT and RT-PCR tests every 48 hours for 15 days. This study represents a non-pre-specified analysis in which we sought to determine if sensitivity of Ag-RDT differed in participants with Delta compared to Omicron variant. Participants who were positive on RT-PCR on the first day of the testing period were excluded. Delta and Omicron variants were defined based on sequencing and date of first RT-PCR positive result (RT-PCR+). Comparison of Ag-RDT performance between the variants was based on sensitivity, defined as proportion of participants with Ag-RDT+ results in relation to their first RT-PCR+ result, for different duration of testing with rapid Ag-RDT. Subsample analysis was performed based on the result of participants' second RT-PCR test within 48 hours of the first RT-PCR+ test.
From the 7,349 participants enrolled in the parent study, 5,506 met the eligibility criteria for this analysis. A total of 153 participants were RT-PCR+ (61 Delta, 92 Omicron); among this group, 36 (23.5%) tested Ag-RDT+ on the same day, and 84 (54.9%) tested Ag-RDT+ within 48 hours as first RT-PCR+. The differences in sensitivity between variants were not statistically significant (same-day: Delta 16.4% [95% CI: 8.2-28.1] vs Omicron 28.2% [95% CI: 19.4-38.6]; and 48-hours: Delta 45.9% [33.1-59.2] vs. Omicron 60.9% [50.1-70.9]). This trend continued among the 86 participants who had consecutive RT-PCR+ result (48-hour sensitivity: Delta 79.3% [60.3-92.1] vs. Omicron: 89.5% [78.5-96.0]). Conversely, the 38 participants who had an isolated RT-PCR+ remained consistently negative on Ag-RDT, regardless of the variant.
The performance of Ag-RDT is not inferior among individuals infected with the SARS-CoV-2 Omicron variant as compared to the Delta variant. The improvement in sensitivity of Ag-RDT noted with serial testing is consistent between Delta and Omicron variant. Performance of Ag-RDT varies based on duration of RT-PCR+ results and more studies are needed to understand the clinical and public health significance of individuals who are RT-PCR+ for less than 48 hours.
有必要了解快速抗原检测（Ag-RDT）在检测新冠病毒Delta（B.1.61.7；AY.X）和奥密克戎（B.1.1.529；BA1）变体方面的表现。
2021年10月18日至2022年1月24日招募无症状参与者，每48小时进行一次Ag-RDT和RT-PCR检测，持续15天。本研究是一项非预先指定的分析，旨在确定与感染奥密克戎变体的参与者相比，感染Delta变体的参与者中Ag-RDT的敏感性是否存在差异。检测期第一天RT-PCR呈阳性的参与者被排除。Delta和奥密克戎变体根据测序和首次RT-PCR阳性结果（RT-PCR+）的日期定义。基于敏感性比较变体之间的Ag-RDT性能，敏感性定义为在不同快速Ag-RDT检测持续时间内，Ag-RDT+结果的参与者相对于其首次RT-PCR+结果的比例。根据参与者在首次RT-PCR+检测后48小时内的第二次RT-PCR检测结果进行亚组分析。
在纳入母研究的7349名参与者中，5506名符合本分析的纳入标准。共有153名参与者RT-PCR呈阳性（61例Delta，92例奥密克戎）；在该组中，36名（23.5%）在同一天检测Ag-RDT呈阳性，84名（54.9%）在首次RT-PCR+后的48小时内检测Ag-RDT呈阳性。变体之间的敏感性差异无统计学意义（同一天：Delta为16.4%[95%CI：8.2-28.1]，奥密克戎为28.2%[95%CI：19.4-38.6]；48小时：Delta为45.9%[33.1-59.2]，奥密克戎为60.9%[50.1-70.9]）。在86名连续RT-PCR呈阳性的参与者中，这一趋势持续存在（48小时敏感性：Delta为79.3%[60.3-92.1]，奥密克戎为89.5%[78.5-96.0]）。相反，38名仅有一次RT-PCR呈阳性的参与者在Ag-RDT检测中始终呈阴性，无论变体如何。
与Delta变体相比，感染新冠病毒奥密克戎变体的个体中Ag-RDT的性能并不逊色。连续检测时Ag-RDT敏感性的提高在Delta和奥密克戎变体之间是一致 的。Ag-RDT的性能因RT-PCR+结果的持续时间而异，需要更多研究来了解RT-PCR阳性少于48小时的个体的临床和公共卫生意义。
