The U.S. Food and Drug Administration (FDA) has published a web page with a list of tests that may be impacted by genetic variants of SARS-CoV-2, such as Omicron.
The issue is whether a diagnostic test will produce accurate results if a mutation occurs in the virus in the gene target that the test is designed to detect. If a test detects multiple gene targets, it will still detect the presence of SARS-CoV-2 via the other targets and produce accurate test results, the FDA said.
In the case of Omicron, specifically, the FDA said a test from Tide Laboratories, which is a single-target test, may be impacted. “This test is expected to fail to detect the SARS-CoV-2 omicron variant (B.1.1.529) due to a nine-nucleotide deletion in the N-gene, spanning positions 28370-28362. The single genetic target of this test covers the portion of the N-gene where the deletions occur,” the FDA said.
The FDA noted that other tests may have one genetic target with reduced sensitivity due to a mutation in the Omicron variant related to the S gene, but test results should not be impacted because the tests detect multiple genetic targets in the virus. However, the agency also said these tests may signal that the Omicron variant is present in a sample, meaning that these specimens should be prioritized for sequencing.
The FDA said its analysis also has identified other tests, which have received emergency use authorization (EUA), that may be impacted by other genetic variants of SARS-CoV-2. However, overall performance should not be impacted because the tests detect multiple targets. The tests are:
- Linea COVID-19 Assay Kit from Applied DNA Sciences
- TaqPath COVID-19 Combo Kit from Thermo Fisher Scientific
- Xpert Xpress SARS-CoV-2, Xpert Xpress SARS-CoV-2 DoD, Xpert Omni SARS-CoV-2 from Cepheid
