Written By: Longjam Dineshwori | Updated : December 30, 2021 11:35 AM IST
Rapid Antigen Tests (RAT) are now commonly used for point-of-care and mass surveillance testing to identify people infected with SARS-CoV-2, virus that causes COVID-19. Most of the currently authorized antigen tests for SARS-CoV-2 can provide results in approximately 15 30 minutes. Though antigen tests are relatively inexpensive, they are generally less sensitive compared to real-time reverse transcription polymerase chain reaction (RT-PCR) tests.
Can rapid antigen tests can detect Omicron? They do detect the Omicron variant but may have reduced sensitivity, said the US Food and Drug Administration (FDA).
The FDA conducted a study in collaboration with the US National Institutes of Health (NIH) to evaluate the performance of some of the currently available antigen tests on the Omicron variant of COVID-19. The researchers used patient samples containing live virus, which is considered the best way to evaluate true test performance in the short-term. Based on the study findings, the researchers concluded that antigen tests can detect the Omicron variant but it may be less sensitive.
Lateral flow test, which rely on the detection of a viral antigen in the patient's sample, is said to be more effective than the antigen test in detecting Covid variants. It is used in the UK an alternative to the PCR test. According to a study from the UK Health Security Agency, lateral flow tests are as equally effective at detecting Omicron and Delta variants of coronavirus.
In such case, the FDA recommends follow-up molecular testing is important for determining a Covid-19 infection. However, it says that if you test positive with an antigen test, you should self-isolate and seek follow-up care with a health care provider to determine the next steps.
