US Food And Drug Administration Calls Rapid COVID-19 Test Inaccurate Detecting Omicron Variant

Illustration of the COVID-19 rapid antigen test kit. (Wikimedia Commons/dronepicr)

JAKARTA - Rapid home tests for COVID-19 are more likely to give false negative results, with the highly mutated Omicron variant compared to its predecessor, the US Food and Drug Administration (FDA) says.

The news comes as the United States faces a major spike in cases that experts say are under-captured as a result of the testing crisis, with long waiting times for more accurate polymerase chain reaction (PCR tests) and in-house test kits in limited supply.

In a statement, the FDA said it was working with the National Institutes of Health (NIH) to study the performance of home tests, also known as 'antigen' tests, on patient samples containing live versions of the Omicron variant.

"Initial data suggest that the antigen test did detect the Omicron variant, but may have reduced its sensitivity," the agency said, citing CNA December 29.

Sensitivity is a measure of how likely the test is to detect a positive.

The previous testing focused on heat-activated virus samples, rather than live, better viruses, and performance degradation has not been seen as of yet, the statement added.

However, the FDA said it would continue to allow the use of the antigen test, which works by detecting the surface protein of the coronavirus, with individuals having to continue to use it according to instructions.

For example, some rapid tests instruct the user to take two tests, at a certain time interval, to confirm a negative result.

If someone tests negative with a rapid test but is thought to have COVID-19, either because of their symptoms or exposure, they are still advised to get a molecular test such as PCR.

This test detects the genetic material of the virus. In addition, this test is more accurate because it can make millions of copies of viral RNA, so even very small amounts can be detected.