The U.S. Food and Drug Administration is advising people to perform repeat, or serial, testing following a negative result on any at-home COVID antigen test, to reduce the risk an infection may be missed (false negative result) and to help prevent people from unknowingly spreading the SARS-CoV-2 virus to others.
At-home COVID-19 antigen tests detect proteins from the SARS-CoV-2, the virus that causes COVID. At-home COVID-19 antigen tests are less likely to detect the SARS-CoV-2 virus than molecular tests, such as polymerase chain reaction (PCR) tests. This is especially true early in an infection or in people who do not have COVID-19 symptoms.
Currently, all at-home COVID-19 antigen tests are FDA-authorized for repeat, or serial use. This means people should use multiple tests over a certain time period, such as 2-3 days, especially when those using the tests don’t have COVID-19 symptoms. The FDA is highlighting the continued need for repeat, or serial testing when people get a negative result with an at-home COVID-19 antigen test, including recommending additional testing over a longer period of time.
Over the course of the COVID-19 pandemic, public health scientists have continued to learn about the SARS-CoV-2 virus and the impact of variants on diagnostic tests that detect SARS-CoV-2. The new recommendations from the FDA are based on the latest study results from people with likely omicron infection showing that repeat testing after a negative at-home COVID-19 antigen test result increases the chance of an accurate result. COVID-19 diagnostic testing remains a cornerstone of our nation’s fight against COVID-19. At-home COVID-19 antigen tests, while not perfect, provide a fast and convenient COVID-19 testing option.
Before taking a COVID antigen test, the FDA suggests users:
- Be aware that at-home COVID-19 antigen tests are less accurate than molecular tests, and they may not detect the SARS-CoV-2 virus early in an infection. Testing soon after being exposed to someone with COVID-19 could lead to a false-negative result, especially if you don’t have symptoms, stressing the significance of repeat testing.
- Have several tests on hand so they can test more than once. You do not need to use the same brand of test each time for repeat testing. The FDA has an authorized list of At-Home OTC COVID-19 Diagnostic Tests.
- Be aware the FDA expects similar performance with Point of Care (POC) COVID-19 antigen tests performed at a clinic or doctor’s office. A negative POC COVID-19 antigen test result should also be followed up with repeat, or serial testing, and an at-home test could be used.