New COVID Variant ‘Stratus’ Spreading Widely
Vaccines Expected to Remain Effective Against XFG Strain
A novel COVID-19 variant, identified as XFG or “Stratus,” is now circulating across the United States and globally. Health officials anticipate that current COVID-19 vaccines will continue to offer protection against symptomatic and severe illness caused by this new strain.
US States Grapple with Rising Case Numbers
The Centers for Disease Control and Prevention (CDC) reports that numerous states are experiencing elevated or very high levels of COVID-19 cases. States such as Alabama, Alaska, California, Delaware, Florida, Hawaii, Kentucky, Louisiana, and Texas are among those with significant case counts. Additionally, Connecticut, Georgia, Indiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Jersey, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, Tennessee, Utah, Virginia, Washington, and Wisconsin are also observing an increase in infections attributed to the XFG variant.
Understanding the ‘Stratus’ Variant
Variant XFG is a recombinant strain, a genetic mix of two earlier variants: F.7 and LP.8.1.2. Scientists note that XFG possesses mutations that might enhance its ability to evade the immune system, although this does not necessarily indicate a faster rate of transmission.
First identified in Southeast Asia in January, XFG’s presence in the U.S. has grown steadily. It represented less than 0% of cases in March, rising to 2% in April, 6% in May, and approximately 14% by the end of June, according to CDC data.
Globally, a similar upward trend has been observed. The World Health Organization (WHO) reported that XFG constituted 7.4% of cases in early May, climbing to 22.7% across 38 countries by the close of June. The WHO has placed XFG on its watchlist, classifying its additional public health risk as “low” worldwide and affirming that existing COVID-19 vaccines are “expected to remain effective to this variant against symptomatic and severe disease.” The WHO currently monitors XFG as a SARS-CoV-2 variant under monitoring (VUM).
Common COVID-19 Symptoms Persist
The CDC continues to list the following as common symptoms associated with COVID-19, including infections by the XFG variant:
- Fever or chills
- Cough
- Fatigue
- Sore throat
- Loss of taste or smell
- Congestion
- Muscle aches
- Shortness of breath
- Headache
- Nausea or vomiting
Data so far suggest that this variant does not lead to more severe illness or higher mortality rates compared to other strains currently in circulation. As of August 2025, the Omicron subvariant BA.5.2.7, a descendant of Omicron, remained the dominant strain globally, accounting for over 60% of sequenced cases, according to GISAID data.