In a new memo, the United States Food & Drug Administration (FDA) has documented and warned both patients and healthcare providers of the risk of Omicron, the latest variant of SARS-CoV-2, displaying reduced sensitivity to rapid antigen tests.
Rapid antigen tests, sometimes referred to as lateral flow tests, are often used in occupational and healthcare settings due to the ability for the test to produce a result within 15 minutes.
Many businesses that have required documentation of a negative COVID-19 test to enter, for example, have often been utilizing these rapid antigen tests for this purpose. The issue of reduced sensitivity, however, means those infected with the Omicron variant may have an increased chance of producing false negatives on a lateral flow test.
Per the FDA:
The FDA is collaborating with the National Institutes of Health’s (NIH) RADx program to study the performance of antigen tests with patient samples that have the omicron variant. RADx recently performed preliminary studies evaluating the performance of some antigen tests using patient samples containing live virus, which represents the best way to evaluate true test performance in the short-term. Early data suggests that antigen tests do detect the omicron variant but may have reduced sensitivity.
At present, the FDA reiterates that rapid tests given FDA-approval to be sold on the market remain authorized. “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 memo reads.
Organizations like the Centers for Disease Control and Prevention (CDC) have long recommended the usage of a molecular test to confirm suspicions of infection or preliminary rapid antigen test results. A molecular COVID-19 test, most often referred to as an RT-PCR test, detects active infection of SARS-CoV-2, the virus that causes COVID-19.
While servicing our greater community and particularly vulnerable patient populations, due to our specialization in also servicing nursing home residents, Aculabs has found its ability to perform same-day-result RT-PCR tests to be one of the most effective tools to assist in the diagnosis of COVID-19. The quick ability to detect active infection of COVID-19 also helps reduce the spread of the virus, important for both patients and healthcare workers.
The FDA memo itself highlights the inherent limitations of all rapid testing, while reiterating the importance of molecular testing. “[If] a person tests negative with an antigen test but is suspected of having COVID-19, such as experiencing symptoms or have a high likelihood of infection due to exposure, follow-up molecular testing is important for determining a COVID-19 infection. 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.”
Outpatients who wish to schedule an appointment for a RT-PCR test may do so at our Patient Portal, while our nursing home clients can continue to order COVID-19 testing through LabGen, our Online Web Portal.
Click here to read the full 12/28/21 memo from the FDA.