In our last update, we discussed the four pathways for making available SARS-CoV-2 tests through FDA’s EUA process. In the time since, FDA introduced a fifth pathway during its April 29, 2020 virtual town hall specific for certain serology tests and on May 4, 2020 FDA updated their Policy for Diagnostic Tests for Coronavirus Disease-2019 during the Public Health Emergency.
FDA previously discussed their collaboration with the National Institutes of Health’s National Cancer Institute (NCI) and National Institute of Allergy and Infectious Diseases (NIAID) and the Centers for Disease Control and Prevention (CDC) to establish a capability at NIH to evaluate serological tests for developers. Following through with this collaboration, FDA issued an umbrella EUA last week for certain antibody tests that undergo validation at NCI, or another government agency designated by the FDA, as a new pathway for getting SARS-CoV-2 antibody tests to market. Tests that the FDA confirms meet the performance and labeling criteria included in that EUA may be added under the umbrella EUA, streamlining the submission and review of antibody tests to prioritize access while also focusing on accuracy.
In the FDA’s updated policy document, FDA published the long-awaited serology EUA templates for manufacturers (Appendix A) and for laboratories (Appendix B) that outline expected performance requirements for serology assays. In addition to cross-reactivity and class specificity testing, serology tests should demonstrate clinical agreement in the desired matrices (serum, plasma, etc.) using 30 confirmed antibody positive samples for each immunoglobulin (IgM and/or IgG) claimed and 75 confirmed negative samples. The minimum performance expected includes minimum overall 90.0% positive percent agreement and overall 95.0% negative percent agreement. For tests specifically identifying IgG or IgM, the minimum positive percent agreement for IgM is 70% and that for IgG is 90%. Additional point estimate requirements for these agreement requirements are detailed in the template as is information for visually read tests, fingerstick tests, and matrix equivalency study requirements.
FDA remains clear that antibody tests have not yet been validated for use in diagnosing SARS-CoV-2 infection, but these may be useful in identifying people why may have been exposed to the virus or who have recovered from COVID-19 infection. To stay current with FDA’s thinking on SARS-CoV-2 diagnostic tests, follow FDA’s COVID-19 IVD-specific FAQ page and tune into their weekly town hall series for which they also post past transcripts.
FDA Guidance for COVID-19 IVDs
Policy for Diagnostic Tests for Coronavirus Disease-2019 during the Public Health Emergency
FAQs on Diagnostic Testing for SARS-CoV-2
Emergency Use Authorizations
EUA template for manufacturers of nucleic acid tests
Virtual Town Hall Series - Immediately in Effect Guidance on Coronavirus (COVID-19) Diagnostic Tests