With summer travel at an all-time high, new COVID-19 variants are brewing. Officials at the World Health Organization (WHO) recently added another one to its list of variants under monitoring: XFG.
XFG is spreading most widely in Southeast Asia, although cases have been reported in 38 countries. In the U.K., it accounts for 30% of COVID-19 infections, and in the U.S., 14% of confirmed cases are XFG, according to the U.S. Centers for Disease Control and Prevention (CDC). (These data are likely incomplete: the CDC notes that since less data are being reported, the variant trackers are not precise.)
Here’s what we know so far about XFG.
It’s a “variant under monitoring“
This designation is the least urgent of WHO’s variant categories, which escalate from “variant under monitoring” to “variant of interest” to “variant of concern.” But while variants under monitoring pose a low immediate risk to people, they show signs of being able to grow and potentially spread more easily than other circulating variants that don’t get an official WHO designation. WHO is watching XFG closely, but it is so new that experts aren’t sure yet what the health consequences of such growth might be.
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XFG is different from existing variants
XFG is still in the Omicron family. It derives from the JN.1 Omicron group, which is the target of the latest COVID-19 vaccine. XFG is a combination of two other variants that have recombined: LF.7 and LP.8.1.2.
It is growing globally. Samples of XFG sent to the global database of genetic virus sequences jumped from 7% of all COVID-19 samples in May 2025 to nearly 23% a few weeks later, according to WHO. Compared to the variant NB.1.8.1—which is currently dominant in many countries, including in the U.S.—XFG contains nine additional mutations in the spike protein.
Vaccines seem to work against it
Scientists are currently studying how well people are protected against severe disease from XFG. Researchers conducted lab studies using human cells and a “pseudovirus” stand-in for XFG, as well as animal studies, and found slightly lower immune responses to XFG.
While the data aren’t complete yet, those results are encouraging since they suggest that existing vaccines used in the U.S., which target JN.1, should continue to provide some protection against severe disease and hospitalization—even if it’s less robust than protection against the JN.1 variant specifically. WHO says the genetic analysis of XFG also shows that antiviral drugs nirmatrelvir (Paxlovid) and remdesivir (Veklury) should also be effective.