New COVID Variant 'Stratus' Spreads Globally: What Are the Symptoms?

Understanding the Rise of the XFG Variant

A new variant of the SARS-CoV-2 virus, known as XFG or "Stratus," is gaining traction in the United States. It has become the third-most common strain during the summer months, indicating a growing presence in the country’s ongoing battle against the pandemic.

First identified in Southeast Asia in January, XFG was initially a minor player in the U.S. with less than 0% of cases attributed to it until May. However, by late June, it had risen to account for up to 14% of reported cases, according to the Centers for Disease Control and Prevention (CDC). This rapid increase has drawn attention from health authorities around the world.

The World Health Organization (WHO) added XFG to its watchlist, but it assessed the global public health risk posed by the variant as "low." In a report released in late June, the WHO also noted that current vaccines are expected to remain effective against symptomatic and severe disease caused by this variant.

What Is the XFG Variant?

XFG is a combination of two existing variants: F.7 and LP.8.1.2. The latter is currently the second most prevalent strain in the United States. While the mutations present in XFG may help it evade immune responses, experts suggest that it is less likely to be highly contagious compared to other dominant variants.

Subhash Verma, a professor of microbiology and immunology at the University of Nevada, Reno, explained that there is currently no clear evidence that XFG causes more severe illness or different symptoms than earlier Omicron variants. He emphasized that there are no immediate public health concerns associated with this variant.

How Common Is XFG?

Although XFG is spreading globally, it has not yet become the primary source of infection in the United States. The CDC has adjusted its tracking methods due to lower reporting rates from states, which has made it more challenging to monitor the spread of variants in real time.

According to the latest data for the two-week period ending June 21, XFG accounted for 14% of U.S. cases. This places it behind NB.1.8.1 (43%) and LP.8.1 (31%), making it the third most prevalent strain. The rise in XFG's prevalence has been gradual but consistent, increasing from 0% in March to 2% in April, 6% in late May, 11% in early June, and finally reaching 14% in late June.

Globally, the WHO observed an uptick in XFG cases in June. Data from 38 countries showed that XFG accounted for 7.4% of positive tests in the first week of May, rising to 22.7% by the end of the month.

What Are the Symptoms of XFG?

There is no evidence that XFG causes distinct symptoms different from those seen with other variants. However, some anecdotal reports on social media and news outlets have linked hoarseness to this strain.

The CDC lists the following as common symptoms of COVID-19:

• Fever or chills
• Cough
• Shortness of breath or difficulty breathing
• Sore throat
• Congestion or a runny nose
• New loss of taste or smell
• Fatigue
• Muscle or body aches
• Headache
• Nausea or vomiting

The agency advises seeking medical care if any of the following symptoms occur:

• Trouble breathing
• Persistent pain or pressure in the chest
• New confusion
• Inability to wake or stay awake
• Depending on skin tone, lips, nail beds, and skin may appear pale, gray, or blue

Health officials continue to monitor the situation closely, emphasizing that current vaccines remain effective against the variant and that no significant public health threats have been identified so far.