The U.S. Food and Drug Administration (FDA) has sent an alert to clinical laboratory staff and healthcare providers regarding the potential effect of SARS-CoV-2 viral mutations causing false-negative results on diagnostic tests.
The FDA said it is monitoring an emerging variant of the SARS-CoV-2 virus from the U.K. known as the B.1.1.7 variant. The B.1.1.7 variant is associated with an increased risk of transmission of COVID-19, so early identification of the variant may help reduce further spread of infection.
The SARS-CoV-2 virus is like all viruses and can mutate over time. And variants like B.1.1.7 could be causing problems with diagnostic tests designed to detect earlier genetic variants of the SARS-CoV-2 virus.
The FDA said 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. Furthermore, laboratories should expect some false results to occur even when very accurate SARS-CoV-2 tests are used.
Diagnostic tests that detect multiple regions of the genome may be less affected by genetic variation in the SARS-CoV-2 genome than tests that rely on the detection of only a single region.
The FDA is keeping an eye on three diagnostic tests -- MesaBiotech Accula, TaqPath COVID-19 combo kit, and Linea COVID-19 assay kit -- which the agency believes are the most likely to be affected by genetic variants of SARS-CoV-2, but the effect appears to be insignificant. Plus, the detection pattern that appears with the TaqPath and Linea diagnostic tests when certain genetic variants are present may help with the early identification of new variants, the agency added.
The FDA is working to ensure authorized tests remain accurate by partnering with test developers and conducting ongoing data analysis to evaluate all currently authorized molecular tests.
"At this time, we believe the data suggests that the currently authorized COVID-19 vaccines may still be effective against this strain," said FDA Commissioner Dr. Stephen Hahn. "The FDA will continue to keep healthcare providers and the public informed of any new information as it becomes available."
To help with the effort to keep abreast of SARS-CoV-2 mutations, the FDA asks stakeholders to report any adverse events or suspected adverse events through MedWatch, the FDA Safety Information and Adverse Event Reporting program.