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Summer is winding down, but COVID-19 activity is heating up, with cases and hospitalizations growing in most states, the latest federal data shows.
This late-summer surge is not unusual, public health experts say, and it’s important to keep in mind that COVID-19 cases are still lower than previous pandemic peaks.
“We’ve really been observing for the past several years that COVID seems to have two waves per year,” says Gavin Harris, M.D., an assistant professor in the Department of Medicine in the Division of Infectious Diseases at the Emory University School of Medicine.
“There’s the classic, traditional respiratory viral season in late fall and throughout the winter, and then COVID seems to also recur in the late summer months,” Harris said.
This year’s late-summer wave, however, comes at a time when many are wondering when updated vaccines will be available and who will be eligible to get them.
Here’s what we know so far about the virus and the vaccines as we head into 2025’s respiratory illness season.
What version of COVID is behind the summer surge?
A variant known as XFG, also nicknamed “Stratus,” is the dominant coronavirus strain currently circulating in the U.S., according to wastewater data collected by the U.S. Centers for Disease Control and Prevention (CDC). It has surpassed NB.1.8.1, which was the most common variant circulating at the beginning of the summer.
According to the World Health Organization, XFG is a hybrid variant of two omicron strains, LF.7 and LP.8.1.2. Harris says the symptoms it causes are similar to those of its predecessors. An infection from this strain can bring fever, chills and respiratory complaints (sore throat, cough, etc.).
Are manufacturers updating the COVID vaccines for the fall?
Yes. Earlier this year, the Food and Drug Administration advised vaccine manufacturers to update their formulas for the 2025-2026 respiratory virus season to target the JN.1 lineage of the omicron variant, preferentially using the LP.8.1 strain.
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