FDA Letter - Viral Mutation Revision Letter The FDA “Viral Mutation Revision Letter” (September 23, 2021) adds new EUA Conditions of Authorization for certain molecular, antigen, and serology COVID-19 IVDs to address potential performance impacts from emerging SARS-CoV-2 variants. It requires developers to update authorized labeling within a defined timeframe to include variant-related limitations, conduct ongoing evaluations of mutation impacts (including multi-analyte targets), and rapidly notify FDA and implement additional risk-mitigation labeling if concerns arise. It is used to standardize post-authorization surveillance and communication about variant-driven performance changes across EUA-authorized tests. primary file regulatory fda-policy 2021-09-23_FDA Letter - Viral Mutation Revision Letter.md regulatory/fda-policy/2021-09-23_FDA Letter - Viral Mutation Revision Letter.md 2021_09_23 pdf Public Domain 1664 2666 gfile-url xfile-github-download-url pdf-gdrive-url pdf-github-url github-markdown-url github-markdown-download-url web-pdf-url web-slides-url youtube-url web-url