A new group of COVID variants are circulating in the U.S., according to tracking by the Centers for Disease Control and Prevention.

The family of variant, called “FLiRT,” after their mutations, are now the dominant strains in the U.S. One of the variants, KP.2, accounts for about 25% of all current infections in the U.S. Another FLiRT variant, KP.1.1, accounts for about 7.5%, behind only three JN strains, one of which, JN.1, was the predominant strain in the U.S. before being overtaken by KP.2.

The FLiRT variants – KP.2 and KP.1.1 – appear to be highly transmissible, TODAY reported, with current vaccines and immunity from prior infection believed to only provide partial protection, experts said.

Such changes are to be expected, according to the CDC.

“Viruses constantly change through mutation and sometimes these mutations result in a new variant of the virus. Some changes and mutations allow the virus to spread more easily or make it resistant to treatments or vaccines. As the virus spreads, it may change and become harder to stop,” the agency said on its website.

What are the symptoms of the newest COVID variants?

The symptoms appear to be similar to those caused by JN.1, which includes:

• Sore throat
• Cough
• Fatigue
• Congestion
• Runny nose
• Headache
• Muscle aches
• Fever or chills
• New loss of sense of taste or smell
• Shortness of breath or difficulty breathing
• Nausea or vomiting
• Diarrhea

COVID patients have reported a wide range of symptoms from mild to severe, typically appearing 2-14 days after exposure.