Omicron is currently behind a majority of COVID-19 cases. Its subvariant BA.5 accounts for nearly 90% of newly reported infections in the United States, per estimates by the Centers for Disease Control and Prevention.

Although hospitalizations and deaths rose, the number of daily cases didn’t. Experts said that cases are being gravely undercounted. A big reason behind this trend is the popularity of at-home tests.

How accurate are at-home COVID tests?

When the pandemic began, at-home tests were considered to be about 70% to 80% accurate. The polymerase chain reaction test, or PCR test — typically available at a hospital or a lab — is usually more on the mark.

But the dawn of omicron has changed the efficacy of these tests.

“As mutation occurs, it may somehow change the structure of these different proteins, which may result in a decrease in detection by the antigen testing,” said Esther Babady, who is chief of the clinical microbiology service at Memorial Sloan Kettering Cancer Center in New York, per CNBC.

“It can also be that earlier in the infection by BA.4 and BA.5, you don’t produce enough of the SARS-CoV-2 protein,” she added.

Data from the FDA suggested that these at-home tests “do detect the omicron variant but may have reduced sensitivity.”

The federal agency consistently tests and monitors the different rapid test brands, according to The Hill.

What should I do if my at-home COVID test is negative but I have COVID symptoms?

If you suspect you have COVID-19, even though your rapid test was negative, the FDA advises to follow up with a PCR test — especially if you are experiencing symptoms.

When is the best time to take a COVID-19 test?

It’s important to test at the right time and that is when you start experiencing symptoms. According to CNET, “asymptomatic people or someone with mild symptoms might be more likely to have a false negative result than someone who has a lot of symptoms.”

“Under these conditions, at-home tests are as effective at detecting omicron as with other variants,” Sandra Adams, a professor of biology and virologist at Montclair State University, told New Jersey Advance Media

“The accuracy varies with when the tests are taken,” she added.

What are the top omicron symptoms to look out for?

As I previously reported, omicron subvariants have a shorter incubation period, which is why the symptoms may appear earlier.

The most common omicron-related symptoms are:

  • Cough.
  • Fatigue.
  • Congestion.
  • Runny nose.