CHICAGO — A new family of COVID variants nicknamed “FLiRT” is spreading across the country, as vaccination rates in Chicago — as well as nationwide — remain concerningly low for some public health experts.

While symptoms and severity seem to be about the same as previous COVID strains, the new FLiRT variants appear to be more transmissible, said infectious disease expert Dr. Robert Murphy.

“A new, more contagious variant is out there,” said Murphy, executive director of Northwestern University’s Institute for Global Health and a professor of infectious diseases at the Feinberg School of Medicine. “COVID-19 is still with us, and compared to flu and RSV, COVID-19 can cause significant problems off-season.”

Murphy urged the public to get up to date on COVID shots, particularly individuals who are at higher risk for severe complications from the virus. While much of the population has some immunity from vaccination or previous COVID infections, Murphy noted that “with COVID-19, immunity wanes over time.”

One FLiRT variant, KP.2, is estimated to account for roughly a quarter of recent COVID cases, according to Centers for Disease Control and Prevention data from late April.

That means it has outpaced the previously most common strain, JN.1, which spurred much of the winter respiratory season’s spike in COVID cases and hospitalizations nationwide, coinciding with a spate of flu and RSV infections around the same time.

The JN.1 variant is estimated to account for about 22% of recent COVID cases across the country, according to CDC data from late April.

Another FLiRT variant, KP.1.1, comprises over 7% of COVID cases nationwide, the CDC data shows. The name “FLiRT” is an acronym using the technical names for the mutations that caused the family of variants.

Hannah Barbian, a virologist at the Regional Innovative Public Health Laboratory at Rush University Medical Center, has been tracking various COVID variants in Chicago. She said her laboratory has detected the KP.2 variant in Chicago but not KP.1.1, though she believes that variant will likely be detected soon as well.

“In general, lineages that emerge in the U.S., we detect them in Chicago,” she said.

...continued

©2024 Chicago Tribune. Visit at chicagotribune.com. Distributed by Tribune Content Agency, LLC.