Why rapid COVID tests aren't more accurate and how scientists hope to improve them

How much should you trust the results of a rapid antigen test? That's a question many people are asking these days amid recent research and anecdotes suggesting these tests may be less sensitive to omicron. Researchers are working fast to figure out what's going on and how to improve the tests.

That includes people like Dr. Wilbur Lam, a professor of pediatrics and biomedical engineering at Emory University and one of the lead investigators assessing COVID-19 diagnostic tests for the federal government. His research team began evaluating rapid antigen tests against live samples of the omicron variant last December in the lab, and in early assessments, he says, some tests failed to detect the coronavirus "at a concentration that we would have expected them to catch it if it were another variant."

That finding prompted the Food and Drug Administration to update its online guidance in late December to note that, while rapid antigen tests do detect the omicron variant, "they may have reduced sensitivity."