The FDA sent out an alert Jan. 8 stating that new coronavirus strains may cause false negative results in molecular COVID-19 tests.
The agency said false negatives can occur in any molecular COVID-19 test if a mutation occurs in the part of the coronavirus' genome that is used by the test to detect infection.
At least 52 cases of a COVID-19 variant first found in the U.K. have been identified in the U.S. Another variant first found in South Africa has been detected in a handful of cases in the U.K., France, Switzerland, Japan, Austria and Zambia.
The FDA said it is working with test developers and evaluating all authorized molecular tests to see how effective they are against COVID-19 variants, and said it believes the risk that the variants will impact overall testing accuracy is low.
"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," said FDA commissioner Stephen Hahn, MD.
Tests that use multiple regions of the virus' genome may be less affected by mutated strains than tests that use just a single region, the FDA said.
The agency named three specific tests — the MesaBiotech Accula, TaqPath COVID-19 Combo Kit, and Linea COVID-19 Assay Kit — as being potentially affected by the COVID-19 variants, but said the impact doesn't appear to be significant. The FDA also said that the detection pattern that the TaqPath and Linea tests use when certain genetic variants are present in the coronavirus may actually help identify new variants of the virus early, which would help reduce the spread of infection.
Read the full FDA alert here.