Dr. Howard Smith Oncall

x Vidcast:  https://youtu.be/YT89x809C88   The 3 common rapid antigen tests currently in use in the US have similar analytic sensitivities for the Omicron variant as they do for the Delta variant but all tests were incapable of detecting infection when low levels of virus were present.  Researchers at Harvard report these findings after testing 30 known Omicron positive samples and 30 known Delta positive samples with each of 3 rapid antigen tests: the BinaxNOW CoVid-19 Antigen Card, the iHealth COVID-19 60 Antigen Rapid Test, and the FlowFlex COVID-19 Antigen Home Test.  Levels of virus in each sample were determined using the Roche PCR assay.   In general, all 3 tests were equally capable of diagnosing the presence of Omicron and Delta with fairly similar sensitivities.  The Binax and the FlowFlex tests were both only decisively positive for slightly higher levels of virus than the iHealth test.  All tests were decisively negative for low virus levels. None of the tests could detect low virus levels with Ct