The U.S. drug regulator said on Friday genetic variants of COVID–19, including the one found in the UK, could lead to false-negative results from some molecular COVID–19 tests, but the risk of the mutations affecting overall testing accuracy is low.The U.S. Food and Drug Administration (FDA) said it has alerted lab staff and healthcare providers to the possible false-negative results and has asked them to consider such results in combination with clinical observations, and use a different test if COVID–19 is still suspected.
In a letter to clinical laboratory staff and health care providers on January 8, 2021, the FDA warned, “The SARS-CoV-2 virus can mutate over time, resulting in genetic variation in the population of circulating viral strains. The U.S. Food and Drug Administration (FDA) is alerting clinical laboratory staff and health care providers that false-negative results may occur with any molecular test for the detection of SARS-CoV-2 if a mutation occurs in the part of the virus’ genome assessed by that test. The FDA monitors the potential effects of genetic variation in molecular tests that have received Emergency Use Authorization (EUA) and has been doing so on an ongoing basis throughout the pandemic.”
The more contagious variant of COVID–19 that has swept through the United Kingdom has been reported in at least five U.S. states, National Institutes of Health Director Francis Collins said this week.
Scientists have said newly developed vaccines should be equally effective against the new variant.
Thermo Fisher Scientific Inc’s TaqPath COVID–19 combo kit and Applied DNA Sciences’ Linea COVID–19 assay kit were found to have significantly reduced sensitivity due to certain mutations, including the B.1.1.7 variant or the so-called UK variant, according to the agency.
However, the detection patterns of both tests may help with the early identification of new variants in patients, the FDA said.
The performance of Mesa Biotech’s Accula test can also be impacted by the genetic variants, the health regulator added.
Mesa said its test would tolerate the genetic variation presented by the new strain and that it should not have an impact on the clinical performance of the test.
Britain said in December rapid lateral flow tests being deployed in the country’s mass-testing program can identify the variant, while Roche said its molecular test for COVID–19 was unlikely to be affected by the mutant strain of the virus.
— By Vishwadha Chander