According to the latest data from the Centers for Disease Control and Prevention (CDC), a COVID variant known as KP.3 is becoming more prominent in the United States.

KP.3, a descendant of Omicron, has become more dominant in recent months. As of mid-April, KP.3 made up only 1.8% of COVID cases. However, by June 8—the most recent date for which variant data are available—KP.3 made up about 25% of cases, making it the most dominant variant.

“The latest data from the CDC projects that approximately a quarter of [COVID-19] infections in the U.S. are currently caused by KP.3,” Hannah Wang, MD, medical director of molecular microbiology and virology at Cleveland Clinic, told Verywell. “KP.3 is closely related to other ‘FLiRT’ variants KP.1 and KP.2, as well as the newly emerging LB.1.” (KP.1, KP.2, and KP.3 are colloquially referred to as the “FLiRT” variants because the technical names of their mutations include the letters “F,” “L,” “R,” and “T.”)

If you’ve recently had COVID-19, there is a good chance you had one of these newer variants. “Together, these variants make up approximately 70% of currently circulating [COVID-19 infections],” Wang said. (That said, unless you submit a viral sample to a laboratory for sequencing, it’s impossible to tell which variant you have or had; at-home tests do not distinguish between COVID-19 variants.)

While there haven’t been any recent changes in the number of deaths or hospitalizations COVID-19 is causing, there was an uptick in the test positivity rate during the first week of June, per CDC data.

Experts say it’s important to test yourself for COVID-19 if you suspect you may have a virus, even though cold and flu season has passed.

What We Know About KP.3

Though KP.3 has become more dominant recently, experts aren’t seeing any new or unusual symptoms.

“There is no evidence yet that symptoms of KP.3 or other FLiRT variants are associated with new symptoms beyond what we’ve seen with recent other strains of the virus,” Wang said.

In general, healthcare providers aren’t seeing anything “new or different” with the new KP.3 variant, Waleed Javaid, MD, epidemiologist and director of Infection Prevention and Control at Mount Sinai Downtown, told Verywell.

There’s no reason to believe rapid tests won’t detect KP.3 or viral mutations. Like other viruses, the virus that causes illness with COVID mutates to become more adaptable. These mutations occur when the virus’s genetic code changes, which may make it easier to infect more people.

However, COVID-19 tests weren’t built to detect only some variants. Rapid tests—which work by detecting proteins known as antigens from the virus that causes COVID-19—can’t specify which variant a person has; they’ve been designed to detect all variants.

When to Test for COVID

Despite the warmer weather, COVID-19 is still circulating. Wang said she has seen the current data, showing an uptick in cases reflected in her region.

“We are seeing a similar frequency and distribution of [the dominant] variants in our region based on local surveillance sequencing data,” she explained. “We are seeing a slight increase in the [COVID-19] test positivity rate, similar to other parts of the country, but overall hospitalization and emergency department visit rates still remain relatively low.”

If you suspect you may have COVID-19, it’s important to test yourself, especially if you plan on being around any immunocompromised members of your community. “Consider testing before coming in contact with people who have a high risk of getting severe COVID-19, like [older adults], people who are immunocompromised, and others with certain medical conditions,” Javaid said.

Two scenarios should prompt you to test, Javaid added: You should use a rapid test if you’ve been exposed to someone with a confirmed case of COVID or if you’re experiencing symptoms of the virus, such as fever or chills, fatigue, cough, or sore throat.

Certain health conditions may prompt certain people to test outside of these two scenarios, Wang added. “There are some other reasons your healthcare provider may recommend testing,” and you should consult with a healthcare provider about how frequently you should test if you have any chronic medical conditions.

• If you test for COVID-19 and your result is positive, seek medical care if you’re at high risk for a severe infection; if not, you should isolate until your symptoms have lifted, per the CDC.
• If you test for COVID-19 and your result is negative, that doesn’t mean you definitely don’t have an infection. You may have tested too early before the virus was detectable.
• If you tested for COVID-19 after experiencing symptoms but got a negative result, you should test again 48 hours later, per the Food and Drug Administration (FDA).
• If you tested for COVID after exposure to the virus but got a negative result, you should test again 48 hours later, then once more 48 hours after the second test, for three tests.