New 'FLiRT' COVID variants spreading quickly across U.S. What are the symptoms?

C. A. Bridges, USA TODAY NETWORK - Florida

A new set of COVID-19 variants has been detected in wastewater surveillance and it's not as playful as the name would suggest.

The variants, labeled KP.2 but nicknamed FLiRT, made up nearly 25% of all cases reported in the U.S. between April 14 and 27, the Centers for Disease Control and Prevention (CDC) reported.

The previous COVID variant to watch was JN.1, which surged over the winter months and currently makes up 22% of COVID cases in the same two-week period. Other JN variants added up to 41% of all U.S. cases, while 7.5% were from FLiRT variant KP1.1, according to CDC data.

Future tracking may be limited because as of May 1, hospitals are no longer required to report COVID-19 hospital admissions, hospital capacity, or hospital occupancy data to the Department of Health and Human Services. "CDC strongly encourages ongoing, voluntary reporting of the data," the agency said.

What is the FLiRT COVID-19 variant?

FLiRT refers to a set of similar variants of the COVID-19 coronavirus that mutated from the JN.1 variant. The name comes from the positions of the mutations in the spike proteins. One of the variants, KP.2, is spreading rapidly.

Megan L. Ranney, MD, dean of the Yale School of Public Health, told WebMD that FLiRT was concerning because of changes in the spike protein that help the COVID virus take hold in the human body. The low rates of American booster vaccination are also a problem, and many people who have not had the virus for some time may be vulnerable to reinfection.

That combination may lead to a summer wave, experts say.

"I think these two mutations together are making KP.2 a better virus in that it maintains its ability to transmit, but also now evades some of the pre-existing immunity in the population,” Andrew Pekosz, Ph.D., virologist at Johns Hopkins University, told TODAY.com.

Early studies suggest that the FLiRT variants may be mutated enough that current vaccines, boosters and immunity may only provide partial protection, but that has not been verified or peer-reviewed.

What are the symptoms of the FLiRT COVID variant?

According to the CDC, the most common symptoms of any variant of COVID-19, including FliRT, are:

  • Fever or chills

  • Cough

  • Sore throat

  • Congestion or runny nose

  • Headache

  • Muscle or body aches

  • Shortness of breath or difficulty breathing

  • Fatigue

  • New loss of taste or smell

  • Brain fog (fuzziness, difficulty thinking or focusing).

  • Nausea or vomiting, mild diarrhea

Some people with COVID are asymptomatic and never display any symptoms, although they can still pass it to others. And many people with COVID have mild symptoms.

Is it the flu, COVID, RSV or a cold? How to tell the symptoms and what to do next

What should I do if I'm exposed to COVID?

If symptoms arise or you've been exposed to someone with COVID, get yourself tested and, if it's positive, observe the recommended isolation and distancing methods. Ask your healthcare provider for the antiviral Paxlovid, which has been shown to be highly effective for people at risk of severe complications.

Earlier this year, the CDC changed its recommendations about isolation for people with COVID-19 to bring them in line with recommendations for other common respiratory viruses. Previously they recommended five days, but now the CDC suggests you stay home if you feel sick whether you tested positive or not, and come back when you're fever-free for 24 hours.

According to the CDC, if you are showing any of the following signs, seek emergency medical care immediately:

  • Trouble breathing

  • Persistent pain or pressure in the chest

  • New confusion

  • Inability to wake or stay awake

  • Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

How many people died from COVID?

While public urgency has lapsed concerning COVID, 8,366 Floridians died from it last year and 2,557 have died already in 2024, according to data from the Florida Department of Health. Even people with mild or no symptoms at first have found themselves dealing with the debilitating effects of long COVID later.

Contributing: Gabe Hauari, USA TODAY

This article originally appeared on The Daytona Beach News-Journal: New COVID variants KP.2, KP1.1, nicknamed 'FLiRT,' spreading quickly

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