As a new, more infectious strain of SARS-CoV-2 spreads further from the United Kingdom and across the United States, the U.S. Food and Drug Administration (FDA) is advising that its impact on molecular tests will likely be low, with three approved tests currently affected.
The variant, known as B.1.1.7, can provide false negative results on tests for SARS-CoV-2 — the virus that causes COVID-19 — according to the FDA. However, such results can occur with any molecular test, and particularly if mutations affect the part of the virus’s genome assessed by that test, as SARS-CoV-2, like all viruses, has the potential to mutate over time. As a result, while the FDA believes the impending impact on testing accuracy to be low, it intends to conduct ongoing data analyses to evaluate 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,” Dr. Stephen Hahn, FDA Commissioner, said. “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.”
Notably, tests that rely on detection within multiple regions of a patient’s genome may be less affected by genetic variation in the SARS-CoV-2 genome than those with a narrow focus on a single region. This means that three currently authorized tests — MesaBiotech Accula, TaqPath COVID-19 Combo Kit, and Linea COVID-19 Assay Kit — may be impacted by the genetic variants, although not significantly. Even then, the FDA notes that the detection pattern provided by genetic variants when facing the TaqPath and Linea tests may actually help with the early identification of new variants.