According to the Infectious Diseases Society Of America (IDSA), the proportion of illnesses caused by KP.2 is rapidly increasing. The other FLiRT variant, KP 1.1 is also circulating in the US. and the world threw travelers
- FLiRT COVID-19 variants, KP.1.1 and KP.2, are spreading in the U.S.
- The current COVID vaccine may not protect against them as well as previous variants.
- It’s not clear if these are more infectious than other variants.
New set of COVID-19 variants, nicknamed FLiRT, has been detected in wastewater surveillance, according to data from the Centers for Disease Control and Prevention.
From April 14 through April 27, the variant, labeled KP.2, makes up about 25% of the cases in the United States, according to the CDC. That makes it the new dominant variant in the country, overtaking JN.1. The JN.1 variant, which spread globally over the winter, made up 22% of COVID-19 cases in the U.S. in the same two-week span.
KP.1.1, another FLiRT variant that is circulating, made up about 7.5% of COVID-19 cases in that two-week span, according to CDC data.
SARS-COV-2, the virus that causes COVID-19, keeps churning out new variants. The latest is a duo, KP.2 and KP.1.1, known as the FLiRT variants, and they’re sparking speculation about a summer wave of new COVID-19 infections.
One FLiRT variant, KP.2 is now the dominant variant in the U.S., and it’s been quickly increasing in cases over the past few weeks. KP.2 now makes up nearly 25% of COVID-19 cases in the U.S., according to data from the Centers for Disease Control and Prevention (CDC).
But KP.2’s sister variant KP.1.1 is also rising in the ranks and currently makes up 7.5% of COVID-19 cases in the country. So, what are the FLiRT variants and how concerned should you be? Infectious disease doctors break down the latest COVID-19 strains.
Variants of FLiRT; KP.2 and KP.1.1
The FLiRT variants are the collective name given to KP.2 and KP.1.1. These are descendants of JN.1.11.1, a spinoff of JN.1, which was the most common variant in the U.S. until last week, explains Thomas Russo, M.D., professor and chief of infectious disease at the University at Buffalo in New York.
The name “FLiRT” isn’t random—it’s based on the technical names for their mutations, according to the Infectious Disease Society of America (IDSA). “These are part of the Omicron family,” Dr. Russo says. “They’re like siblings.”
There’s not a lot of detail about these variants available at the moment, but preliminary research shows that KP.2 has three changes in its spike protein compared to JN.1, Dr. Russo says. (In case you’re not familiar, the spike protein is what SARS-CoV-2 uses to latch onto your cells and infect you.)
How contagious are the FLiRT variants?
It’s worth pointing out that the portion of cases caused by KP.2 is increasing while the portion of cases caused by other variants is decreasing. That implies that there is something about KP.2 that gives it an advantage over the others, Dr. Russo says.
“It looks like KP.2 is less infectious than JN.1 but more immune evasive, which is why it’s increasing in prevalence,” Dr. Russo says.
Should be concerned about the FLiRT variants?
As of now, doctors say there’s nothing to suggest that the FLiRT variants are any more concerning to the general population than other recent COVID-19 variants. However, Dr. Schaffner points out that there is some early data that show KP.2 may be able to evade the protection from the vaccine a little more than previous COVID vaccines. (More on that in a moment.)
“As SARS-CoV2 continues to circulate, it will always be generating new variants,” says infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security.
How can distinguish FLiRT from other variants?
Doctors say that’s pretty tough. There’s nothing that you or your doctor would notice that would indicate that you have a FLiRT variant as opposed to another COVID-19 variant, Dr. Russo says.
In fact, the only way that the CDC has data on different variants is through genomic sequencing, which looks at the genetic code of the virus to see which variant you have—and that’s not something you’d get from even the best at-home COVID-19 tests or that your doctor would get from a rapid test in their office.
What are the symptoms of the FLiRT variants, KP.1.1 and KP.2?
Doctors say it’s hard to tell for sure right now, but Dr. Schaffner points out that previous variants haven’t looked that different when it comes to symptoms, either.
According to the CDC, these are the most common symptoms of COVID-19:
- Fever or chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue
- Muscle or body aches
- Headache
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
- Diarrhea
Still, “the loss of taste and smell seems less common now,” Dr. Schaffner says. It could be because of changes in the virus itself or because people have developed more immunity, either through vaccinations or being infected, he says. “We’re all experienced now with COVID,” he adds.
Is there a vaccine for the FLiRT variants?
Yes, the COVID-19 vaccine is protective against the FLiRT variants, although there is data to suggest that it might not be as effective as it’s been against other strains.
“It may be off to the side a little bit in regards to protection from the vaccine,” Dr. Schaffner says. “Protection is not zero, but it’s not quite as good as it was before.”
If you’re in a high-risk group and you haven’t gotten the updated vaccine, Dr. Schaffner recommends getting it to increase your protection throughout the summer. “For sure when the new vaccine comes out in the fall, we should all get it,” he says.
Do the FLiRT variants increase the risk for long COVID?
That’s not clear. “This is still very early days,” Dr. Schaffner says. As of right now, there is no indication that the FLiRT variants are any more risky for developing long COVID than other variants. However, that may change over time.
