FDA: Rapid COVID-19 Tests May Be Less Accurate for Omicron Variant

Employees of Nomi Health check in a long line of people for COVID-19 tests in North Miami on Dec. 21, 2021. Marta Lavandier/AP Photo

The U.S. Food and Drug Administration (FDA) said rapid COVID-19 tests could be less accurate when testing someone with the new Omicron variant.

Rapid tests, including the very commonly used antigen tests, can detect the Omicron variant, “but may have reduced sensitivity,” the FDA said in a statement on Dec. 28.

The FDA’s findings regarding at-home tests were based on preliminary studies conducted by the agency and the National Institutes of Health’s RADx program.

“Prior to completing these live virus tests, RADx conducted initial laboratory tests using heat-inactivated samples for some of the currently available antigen tests, which were able to detect the Omicron variant, with similar performance when detecting other variants,” the federal health agency said. “Heat-inactivated samples are patient samples with Omicron variant that have been heat-treated so that the virus is no longer live.”

However, the FDA said that people shouldn’t avoid using antigen tests despite the apparent inaccuracy issues.

“The FDA continues to authorize the use of these tests as directed in the authorized labeling and individuals should continue to use them in accordance with the instructions included with the tests,” the agency’s statement reads. “Antigen tests are generally less sensitive and less likely to pick up very early infections compared to molecular tests.”

According to the FDA statement, if an individual tests negative but has COVID-19 symptoms, it notes that “follow-up molecular testing is important for determining a COVID-19 infection.”

And “if a person tests positive with an antigen test, they should self-isolate and seek follow-up care with a health care provider to determine the next steps,” the agency said.

Last week, the FDA approved drugmaker Roche’s at-home rapid COVID-19 test kit, which can be used by people as young as 14. Roche, in a statement, said the kit is “able to produce accurate, reliable and quick results in as few as 20 minutes,” including with Omicron.

The warning comes as the UK Health Security Agency earlier this month found that those who contracted the variant, which was named by the World Health Organization in November, are less likely to become severely sick as compared with individuals who contract the Delta variant.

Two UK studies, including one from Imperial College London, estimated that Omicron patients were 20 to 25 percent less likely to need hospital care, while between 40 and 45 percent were less likely to be hospitalized for one night or more.

COVID-19 is the illness caused by the CCP (Chinese Communist Party) virus.