FDA Monitoring Impact of SARS-CoV-2 Mutations on Results of Authorized COVID-19 Molecular Tests

The US Food and Drug Administration (FDA; Silver Spring, MD, USA) has alerted clinical laboratory staff and health care providers that it is monitoring the potential impact of viral mutations, including an emerging variant from the UK known as the B.1.1.7 variant, on authorized SARS-CoV-2 molecular tests.

The FDA has also warned that false negative results can occur with any molecular test for the detection of SARS-CoV-2 if a mutation occurs in the part of the virus’s genome assessed by that test. The SARS-CoV-2 virus can mutate over time, like all viruses, resulting in genetic variation in the population of circulating viral strains, as seen with the B.1.1.7 variant. The presence of SARS-CoV-2 genetic variants in a patient sample can potentially change the performance of a SARS-CoV-2 test. The FDA has reminded clinical laboratory staff and health care providers about the risk of false negative results with all laboratory tests, including molecular tests. Laboratories should expect some false results to occur even when very accurate SARS-CoV-2 tests are used, according to the FDA. However, the FDA believes that the risk that these mutations will impact overall testing accuracy is low. Tests that rely on the detection of multiple regions of the genome may be less impacted by genetic variation in the SARS-CoV-2 genome than tests that rely on detection of only a single region.


According to the FDA, three currently authorized molecular tests, MesaBiotech Accula, TaqPath COVID-19 Combo Kit, and Linea COVID-19 Assay Kit, may be impacted by genetic variants of SARS-CoV-2, although the impact does not appear to be significant. Importantly, the detection pattern that appears with the TaqPath and Linea diagnostic tests when certain genetic variants are present may help with early identification of new variants in patients to reduce further spread of infection. The FDA has said that it is taking additional actions to ensure authorized tests remain accurate by working with test developers and conducting ongoing data analysis to evaluate all currently authorized molecular tests.

“The FDA will continue to monitor SARS-CoV-2 genetic viral variants to ensure authorized tests continue to provide accurate results for patients,” said FDA Commissioner Stephen M. Hahn, M.D. “While these efforts continue, we are working with authorized test developers and reviewing incoming data to ensure that health care providers and clinical staff can quickly and accurately diagnose patients infected with SARS-CoV-2, including those with emerging genetic variants. At this time, we believe the data suggests that the currently authorized COVID-19 vaccines may still be effective against this strain. The FDA will continue to keep health care providers and the public informed of any new information as it becomes available.”

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US Food and Drug Administration (FDA)