The evaluated SARS-CoV-2 antigen rapid fluorescence immunoassays reliably identified patients within the first 5 days of symptom onset, when respiratory secretions carried high viral loads. This high performance suggests that these tests might play an important role for future PCR-independent strategies to detect early or infective cases.
Rapid SARS-CoV-2 antigen detection by immunofluorescence - a new tool to detect infectivity