Evaluation of Four Strategies for SARS-CoV-2 Detection: Characteristics and Prospects

The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed an enormous burden on the global public health system and has had disastrous socioeconomic consequences. Currently, single sampling tests, 20-in-1 pooling tests, nucleic acid point-of-care tests (POCTs), and rapid antigen tests are implemented in different scenarios to detect SARS-CoV-2, but a comprehensive evaluation of them is scarce and remains to be explored. In this study, 3 SARS-CoV-2 inactivated cell culture supernatants were used to evaluate the analytical performance of these strategies. Additionally, 5 recombinant SARS-CoV-2 nucleocapsid (N) proteins were also used for rapid antigen tests. For the wild-type (WT), Delta, and Omicron strains, the lowest inactivated virus concentrations to achieve 100% detection rates of single sampling tests ranged between 1.28 × 10² to 1.02 × 10³, 1.28 × 10² to 4.10 × 10³, and 1.28 × 10² to 2.05 × 10³ copies/mL. The 20-in-1 pooling tests ranged between 1.30 × 10² to 1.04 × 10³, 5.19 × 10² to 2.07 × 10³, and 2.59 × 10² to 1.04 × 10³ copies/mL. The nucleic acid POCTs were all 1.42 × 103 copies/mL. The rapid antigen tests ranged between 2.84 × 10⁵ to 7.14 × 10⁶, 8.68 × 10⁴ to 7.14 × 10⁶, and 1.12 × 10⁵ to 3.57 × 10⁶ copies/mL. For the WT, Delta AY.2, Delta AY.1/AY.3, Omicron BA.1, and Omicron BA.2 recombinant N proteins, the lowest concentrations to achieve 100% detection rates of rapid antigen tests ranged between 3.47 to 142.86, 1.74 to 142.86, 3.47 to 142.86, 3.47 to 142.86, and 5.68-142.86 ng/mL, respectively. This study provided helpful insights into the scientific deployment of tests and recommended the full-scale consideration of the testing purpose, resource availability, cost performance, result rapidity, and accuracy to facilitate a profound pathway toward the long-term surveillance of coronavirus disease 2019 (COVID-19). IMPORTANCE In the study, we reported an evaluation of 4 detection strategies implemented in different scenarios for SARS-CoV-2 detection: single sampling tests, 20-in-1 pooling tests, nucleic acid point-of-care tests, and rapid antigen tests. 3 SARS-CoV-2-inactivated SARS-CoV-2 cell culture supernatants and 5 recombinant SARS-CoV-2 nucleocapsid proteins were used for evaluation. In this analysis, we found that for the WT, Delta, and Omicron supernatants, the lowest concentrations to achieve 100% detection rates of single sampling tests ranged between 1.28 × 10² to 1.02 × 10³, 1.28 × 10² to 4.10 × 10³, and 1.28 × 10² to 2.05 × 10³ copies/mL. The 20-in-1 pooling tests ranged between 1.30 × 10² to 1.04 × 10³, 5.19 × 10² to 2.07 × 10³, and 2.59 × 10² to 1.04 × 10³ copies/mL. The nucleic acid POCTs were all 1.42 × 10³ copies/mL. The rapid antigen tests ranged between 2.84 × 10⁵ to 7.14 × 10⁶, 8.68 × 10⁴ to 7.14 × 10⁶, and 1.12 × 10⁵ to 3.57 × 10⁶ copies/mL. For the WT, Delta AY.2, Delta AY.1/AY.3, Omicron BA.1, and Omicron BA.2 recombinant N proteins, the lowest concentrations to achieve 100% detection rates of rapid antigen tests ranged between 3.47 to 142.86, 1.74 to 142.86, 3.47 to 142.86, 3.47 to 142.86, and 5.68 to 142.86 ng/mL, respectively.