The Coviral Portal: Multi-Cohort Viral Loads and Antigen-Test Virtual Trials for COVID-19

BackgroundRegulatory approval of new over-the-counter tests for infectious agents such as SARS-CoV-2 has historically required that clinical trials include diverse groups of specific patient populations, making the approval process slow and expensive. Showing that populations do not differ in their viral loads--the key factor determining test performance--could expedite the evaluation of new tests. Methods46,726 RT-qPCR-positive SARS-CoV-2 viral loads were annotated with patient demographics and health status. Real-world performance of two commercially available antigen tests was evaluated over a wide range of viral loads. An open-access web portal was created allowing comparisons of viral-load distributions across patient groups and application of antigen-test performance characteristics to patient distributions to predict antigen-test performance on these groups. FindingsIn several cases distributions were surprisingly similar where a difference was expected (e.g. smokers vs. non-smokers); in other cases there was a difference that was the opposite direction from expectations (e.g. higher in patients who identified as White vs. Black). Sensitivity and specificity of antigen tests for detecting contagiousness were similar across most groups. The portal is at https://arnaoutlab.org/coviral/. ConclusionsIn silico analyses of large-scale, real-world clinical data repositories can serve as a timely evidence-based proxy for dedicated trials of antigen tests for specific populations. Free availability of richly annotated data facilitates large-scale hypothesis generation and testing. FundingFunded by the Reagan-Udall Foundation for the FDA (RA and JEK) and via a Novel Therapeutics Delivery Grant from the Massachusetts Life Sciences Center (JEK).