Alert on Molecular Tests Used with Covid-19 Emerging Variant
FDA is alerting clinical laboratory staff and health care providers about the potential impact of viral mutations, including an emerging variant from the United Kingdom known as the B.1.1.7 variant, on authorized Covid-19 molecular tests, and that false negative results can occur with any molecular test if a mutation occurs in the part of the virus’s genome assessed by that test. “The FDA is taking additional actions to ensure authorized tests remain accurate by working with test developers and conducting ongoing data analysis to evaluate all currently authorized molecular tests,” the alert says. The agency believes that the risk that these mutations will impact overall testing accuracy is low, it says, adding that data suggest that the currently authorized Covid-19 vaccines may still be effective against the strain.
Three authorized molecular tests, MesaBiotech Accula, TaqPath COVID-19 Combo Kit, and Linea COVID-19 Assay Kit, may be impacted by Covid-19 genetic variants, but the impact does not appear to be significant, the alert says. “Importantly, the detection pattern that appears with the TaqPath and Linea diagnostic tests when certain genetic variants are present may help with early identification of new variants in patients to reduce further spread of infection,” it says. “The recently identified B.1.1.7 variant has been associated with an increased risk of transmission, therefore early identification of this variant in patients may help reduce further spread of infection.”