Pollock, Nira R.

SUMMARY The emergence and worldwide dissemination of SARS-CoV-2 required both urgent development of new diagnostic tests and expansion of diagnostic testing capacity on an unprecedented scale. The rapid evolution of technologies that allowed testing to move out of traditional laboratories and into point-of-care testing centers and the home transformed the diagnostic landscape. Four years later, with the end of the formal public health emergency but continued global circulation of the virus, it is important to take a fresh look at available SARS-CoV-2 testing technologies and consider how they should be used going forward. This review considers current use case scenarios for SARS-CoV-2 antigen, nucleic acid amplification, and immunologic tests, incorporating the latest evidence for analytical/clinical performance characteristics and advantages/limitations for each test type to inform current debates about how tests should or should not be used.

Abstract Diagnostic testing is a critical tool to mitigate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, but molecular testing capacity remains limited. Rapid diagnostic tests (RDTs) that detect SARS-CoV-2 protein antigens (Ag) offer the potential to substantially expand testing capacity and to allow frequent, large-scale, population screening. Testing is simple, rapid (results generally available within 15 minutes), and applicable for diagnosis at point of care. However, implementation of Ag RDTs requires a detailed understanding of test performance and operational characteristics in each testing scenario and population being evaluated. Successful implementation of Ag RDTs on a large scale should combine testing with technical oversight and with clinical and public health infrastructure, and will require production at levels much higher than presently possible. In this commentary, we provide detailed considerations for Ag RDT assessment and use cases to encourage and enable broader manufacturing and deployment.