Emerging XFG 'Stratus' COVID-19 Variant: Key Symptoms and Global Spread

A new COVID-19 variant, designated as XFG and commonly referred to as 'Stratus', has recently surfaced, prompting health authorities to closely monitor its spread. As of late June 2025, Stratus has been detected in 38 countries, with the World Health Organization (WHO) officially categorizing it as a Variant Under Monitoring (VUM). This variant, classified as a recombinant subvariant of the Omicron lineage, exhibits unique mutations that differentiate it from its predecessors.

The designation 'Stratus' reflects its genesis from a blend of previous Omicron strains, specifically LF.7 and LP.8.1.2. Recombinant variants like Stratus typically begin with the letter 'X', indicating their complex genetic makeup. According to a recent study published in The Lancet, Stratus has been genetically sequenced over 1,648 times globally, indicating significant transmission potential.

Despite the increase in cases, the WHO has assessed the global public health risk posed by Stratus as low, indicating that it does not appear to lead to more severe illness than previous strains. Current vaccines continue to provide substantial protection against severe disease and hospitalization, even in the presence of this variant.

Experts note that the symptoms associated with the Stratus variant are generally mild, particularly among vaccinated individuals. However, one notable symptom that distinguishes Stratus from other variants is the increased incidence of hoarseness or a raspy voice, which is believed to be a result of the variant's targeting of the upper respiratory tract. Other common symptoms include scratchy throat, nasal congestion, fatigue, low-grade fever, and muscle aches. Interestingly, the loss of smell or taste, which was prevalent with earlier variants, appears to be less common with Stratus.

Dr. Emily Thompson, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, stated, "While the symptoms are mild, the presence of hoarseness is something we are closely monitoring as it may indicate a unique interaction with the respiratory system."

The potential for Stratus to evade immune responses is another area of concern for scientists. The mutations in its spike protein may allow it to partially escape the antibodies generated from prior infections or vaccinations. Nonetheless, the WHO reassures that existing vaccines remain effective against severe outcomes.

The emergence of the Stratus variant underscores the ongoing evolution of the SARS-CoV-2 virus, necessitating continuous vigilance from public health officials and the scientific community. The WHO advises that, while caution is warranted, there is no immediate cause for alarm based on current data.

In light of Stratus's spread, health officials encourage continued adherence to public health measures, particularly in crowded or poorly ventilated settings. Further research will be essential in understanding the full implications of this new variant and its potential impact on global health in the coming months.

**Disclaimer:** This article is intended for informational purposes only and should not replace professional medical advice. Always consult healthcare providers regarding any medical concerns.