Currently available antigen tests may not be able to detect the omicron SARS-CoV-2 variant as well as they could detect previous variants, an early laboratory study has found.
Antigen tests “do detect the omicron variant but may have reduced sensitivity,” the Food and Drug Administration reported in a Dec. 28 website post. The agency is studying the performance of the tests with patient samples containing the omicron variant in collaboration with the National Institutes of Health.
In the meantime, antigen tests are still federally authorized for use as directed, the FDA said. They are generally less sensitive than molecular tests. But their overall ability to detect infections, especially as part of serial testing programs, has been an infection control-plus for long-term care operators, who were provided with rapid, point-of-care antigen test kits starting in 2020.
Some test makers, such as Quidel, have found evidence that their devices do detect the omicron variant. Abbott’s BinaxNow system detects omicron in live samples “at equivalent sensitivity as other variants,” the company said in a statement last week.
Laboratory data do not replace clinical studies using patient samples with live virus, the FDA cautioned regarding its own new findings. Clinical studies are ongoing, it said.
