COVID-19 variants may lead to false negatives with molecular tests - FDA

The FDA, however, said the risk that these mutations will impact overall testing accuracy is low.

Signage is seen outside of FDA headquarters in White Oak, Maryland. (photo credit: REUTERS)
Signage is seen outside of FDA headquarters in White Oak, Maryland.
(photo credit: REUTERS)
Genetic variants of the novel coronavirus, including the one found in UK, could impact the performance of some molecular COVID-19 tests and lead to false negative results, the US Food and Drug Administration (FDA) said on Friday.
The agency has alerted clinical laboratory staff and health care providers to the possible false negative results from any molecular test, and has asked them to consider such results in combination with clinical observations, and repeat testing with a different test if COVID-19 is still suspected.
The FDA, however, said the risk that these mutations will impact overall testing accuracy is low.
The more contagious variant of COVID-19 that has swept through the United Kingdom has been reported in at least five states in the US, National Institutes of Health Director Francis Collins said this week.
Scientists have said newly developed vaccines should be equally effective against the new variant.
The FDA said on Friday its analysis found the performance of three tests, that have received emergency use authorization, to be impacted by genetic variants of the coronavirus, but noted that the impact does not appear to be significant.
Thermo Fisher Scientific Inc's TaqPath COVID-19 combo kit and the Linea COVID-19 assay kit were found to have significantly reduced sensitivity from mutations, including the B.1.1.7 variant or the so-called UK variant, according to the agency.
However, since both the tests are designed to detect multiple genetic targets, the overall test sensitivity should not be impacted, the FDA said.
Mesa Biotech's Accula SARS-COV-2 test performance can also be impacted by the genetic variants, according to the health regulator.