FLiRT COVID variant is now the leading variant across the US

The most recent update to the CDC COVID Data Tracker dashboard indicates that between April 28, 2024, and May 11, 2024, the newest COVID variant, KP.2, accounted for 28.2% of all reported COVID-19 cases across the United States. This variant is an Omicron subvariant that is very closely related to the JN.1 Omicron variant.

CDC data revealed that the following variants account for a detectable percentage of COVID cases in the US in descending order:

1. KP.2 (28.2%)
2. JN.1 (15.7%)
3. JN.1.7 (13.3%)
4. JN.1.16 (10.0%)
5. JN.1.13.1 (8.0%)
6. KP.1.1 (7.1%)
7. JN.1.11.1 (5.4%)
8. JN.1.8.1 (4.8%)
9. KQ.1 (3.8%)
10. JN.1.18 (2.6%)
11. JN.1.13 (0.1%)

David Ho, MD, a virologist at Columbia University, told the New York Times that the KP.2 subvariant may be better at infiltrating immune systems than JN.1, making it slightly more infectious. He attributes these differences to changes in the spike protein.

Although the proportion of cases attributed to KP.2 has risen over the past months, it does not indicate a significant change in COVID-19 rates overall.  The dashboard estimates that positive tests have only increased by 0.1% in the past week, and there has been no substantial change in COVID-19 deaths. Additionally, hospitalization rates associated with COVID-19 declined by 26.7% between April 14, 2024, and April 20, 2024. Furthermore, COVID-19-related emergency department visits decreased by 7.6% throughout the past week.

While COVID rates seem relatively stable, it will likely take some time to assess whether the emergence of KP.2 will lead to a rise in cases.

“I don’t want to say that we already know everything about KP.2,” said Ziyad Al-Aly, MD, the chief of research and development at the Veterans Affairs St. Louis Healthcare System, in a statement to the NYT. “But at this time, I’m not seeing any major indications of anything ominous.”

The symptoms of the KP.2 variant are similar to those of other COVID variants, according to Peter Chin-Hong, MD, an infectious disease specialist at the University of California, San Francisco, in the NYT. These symptoms include sore throat, runny nose, coughing, headache, body aches, fever, congestion, fatigue, and shortness of breath. However, this variant also may be linked to diarrhea, nausea, and vomiting.

Although this variant differs from what the current COVID-19 vaccines are designed to protect against, experts maintain that the available vaccines will offer some protection against the new variant, and formulations for new vaccines could offer greater protection.

“I still suspect that our immunity, whether from natural infection or vaccine, is still going to hold up well against this and protect us from severe disease, but maybe it’ll be just a little bit less efficacious than it would have been against some of these more recent variants … [but] I’m not too concerned,” Scott Roberts, MD, an infectious-disease physician at Yale School of Medicine, told the Washington Post. “We know COVID’s going to evolve over time, and this is sort of the next iteration of it.”