During the holiday season, many Americans opted for at-home COVID-19 testing ahead of many family and social gatherings.
However, with a continuing rise in cases across the country and here in New York state, many are starting to question how accurate these rapid antigen tests are at detecting the highly contagious omicron variant.
Dr. Chris Morley is a professor and chair of Public Health and Preventative Medicine at Upstate Medical University. He said it’s no secret that at-home tests aren’t fool-proof, especially for those who are asymptomatic.
“If you're not symptomatic, we've known since the number of rapid tests came on the market that they have a lower sensitivity,” he said.
Morley added that a false negative could be the result of testing someone with a low viral load, which is common in asymptomatic cases.
“Most of the rapid tests on the market, we've always known, especially in asymptomatic people, [tests] have had about a 50% sensitivity rate–which means they can potentially miss a lot of cases, especially in asymptomatic people,” said Morley.
In fact, in late December, the Food and Drug Administration issued a warning that at-home antigen tests do have reduced sensitivity to omicron.
“However, that's based on lab data, not on a widespread trial or you know, whole population data,” he said.
Morley said that while the omicron variant is different from previous strains, the nucleocapsid protein remains the same. That’s the protein that’s typically detected in both antigen and PCR tests, so he says, on paper, at-home tests should work.
“So for the most part, rapid antigen tests should, in theory, be working just about as well,” he said.
Even Abbott, the company that manufactures one of the most popular at-home tests–BinaxNow–said in a statement recently that their tests can indeed detect the new variant.
The bottom line is that omicron just hasn’t been around long enough to complete comprehensive studies about the efficacy of antigen tests at detecting it. In the meantime, experts recommend that if you’re presenting symptoms, a PCR test will provide you with the most accurate results.
