Clinical Validation of Automated and Rapid mariPOC SARS-CoV-2 Antigen Test

Novel SARS coronavirus causing COVID-19 was recognized in late 2019. Diagnostics was quickly ramped up worldwide based on the detection of viral RNA. Based on the scientific knowledge for pre-existing coronaviruses, it was expected that the RNA of this novel coronavirus will be detected at significant rates from symptomatic and asymptomatic individuals due to existence of non-infectious RNA. To increase the efficacy of diagnostics, surveillance, screening and pandemic control, rapid methods, such as antigen tests, are needed for decentralized testing and to assess infectiousness. The objectives were to verify analytical sensitivity and specificity, and assess the clinical sensitivity, specificity and usability of a novel automated mariPOC SARS-CoV-2 test based on sophisticated optical laser technology detecting viral structure proteins. Analytical performance was verified using bacterial and viral preparations. Clinical performance of the test was evaluated against qRT-PCR in a retrospective study with nasopharyngeal swab specimens (N=211) collected from symptomatic patients suspected of acute SARS-CoV-2 infections. Sensitivity and specificity of the mariPOC test were 92.3% (12/13) and 100.0% (198/198), respectively. The test9s limit of detection was 22 PFU/test and it had no cross-reactions with the tested respiratory microbes. Our study shows that the mariPOC can detect infectious individuals already in 20 minutes while clinical sensitivity close to qRT-PCR is achieved in two hours or less. The test targets conserved epitopes of SARS-CoV-2 nucleoprotein, making it robust against strain variations. The new test is a promising and versatile tool for syndromic testing of symptomatic cases and for high capacity infection control screening.