Abstract
Rapid qualitative antigen tests are essential for the management of COVID-19, but their sensitivity and specificity vary. This study prospectively evaluated the diagnostic performance of a newly developed product, the SARS-CoV-2 Rapid antigen test 2.0 （Roche Diagnostics GmbH, Mannheim, Germany） in anterior nasal and nasopharyngeal samples, comparing results with reverse transcription polymerase chain reaction（RT-PCR）in nasopharyngeal samples. The symptomatic participants or asymptomatic participants with a history of close contact with COVID-19 patients were consecutively enrolled. The study also evaluated the sensitivities across different viral loads in pooled samples with known viral RNA levels and compared them with those of a previous product. Among 287 participants, 283 were symptomatic and 187 tested positive for SARS-CoV-2; 179 nasopharyngeal samples had viral loads ≥ 1,000 copies/test. The antigen test had a sensitivity of 92.5%（ 95% confidence interval ［CI］: 87.8%-95.8%） and specificity of 100%（ 95% CI: 96.4%-100%） in anterior nasal samples. When stratified by viral loads in the corresponding nasopharyngeal samples（≥ 105 , ≥ 104 to < 105 , ≥ 103 to < 104 , ≥ 102 to < 10 3 , and < 102 viral copies/test）, the sensitivities were 95.9%, 91.3%, 70.0%, 100%, and 40%, respectively. For nasopharyngeal samples, the sensitivity and specificity of the antigen test were 97.3%（95% CI: 93.9%-99.1%）and 99.0%（95% CI: 94.6%-100%）, respectively. In the evaluation of pooled samples, the SARS-CoV-2 Rapid antigen test 2.0 demonstrated a lower limit of detection for SARS-CoV-2 compared to the previous product. The SARS-CoV-2 Rapid antigen test 2.0 exhibited sufficient diagnostic performance, with improved detection performance over the previous products.
