NEW YORK, May 24 (Reuters) - The so-called FLiRT

variants of SARS-CoV-2 coronavirus that cause COVID-19 have been

the dominant forms of the virus circulating this year globally,

according to the World Health Organization

The moniker FLiRT is an acronym for the locations of the

mutations the variants share on the virus' spike protein. One of

them, called KP.2, has become the most commonly circulating

variant in the United States over the past month, according to

the U.S. Centers for Disease Control and Prevention.

Here is what you need to know about FLiRT.

HOW ARE THE FLIRT VARIANTS DIFFERENT FROM PREVIOUS

VARIANTS?

The FLiRT variants, which also include KP.2's "parental" lineage

JN.1, have three key mutations on their spike protein that could

help them evade antibodies, according to Johns Hopkins

University.

ARE THE FLIRT VARIANTS MORE CONTAGIOUS OR LIKELY TO CAUSE

MORE SEVERE ILLNESS?

Dr. Aaron Glatt, chief of infectious diseases at Mount

Sinai South Nassau Hospital in Oceanside, New York, and a

spokesperson for the Infectious Diseases Society of America said

he has not seen evidence of an uptick in disease or

hospitalizations, based on the data he tracks and experience

with his own patients.

"There have been some significant changes in the variants,

but I think in recent times it's not been as important, probably

because of the immunity many, many people already have" from

prior illness and vaccination.

CDC data suggests that COVID-related hospitalizations have

trended downwards in recent weeks and the number of patients in

emergency departments who have tested positive for COVID has

been about flat for the past month.

Data suggests that COVID rates are also down year-over-year.

The rate of COVID hospitalizations is less than half than a year

earlier, and the amount of the antiviral Paxlovid currently

being prescribed for COVID-19 is down around 60% from last year,

according to analyst notes.

DO CURRENT VACCINES WORK AGAINST THE FLIRT VARIANTS?

The current vaccines should still have some benefit against

the new variants, Glatt said.

Since 2022, health regulators have asked vaccine makers to

design new versions of the COVID-19 vaccines to better target

circulating variants. Last month, Europe's regulator said

vaccine makers should target the JN.1 variant. U.S. experts and

regulators will meet to discuss vaccine design on June 5 after

having postponed the meeting from May 16 in order to have more

time to "obtain surveillance data and other information."

Makers of vaccines based on messenger RNA (mRNA) technology

- Pfizer ( PFE ) with partner BioNTech, and Moderna ( MRNA )

- say they are waiting for the June 5 meeting before

settling on the design of their next vaccines.

Novavax ( NVAX ), which makes a more traditional

protein-based vaccine that takes longer to manufacture, has

begun producing a shot targeting JN.1 consistent with

recommendations from European regulators.