
Meet Stratus: The New COVID Variant You Need to Know About!
2025-07-08
Author: Yu
COVID's Latest Challenge: The XFG Variant Explained
Brace yourselves! The world is now facing yet another variant of SARS-CoV-2, the virus behind COVID-19, and it’s called XFG, or ‘Stratus’ for short. The World Health Organization (WHO) has classified it as a "variant under monitoring" as of late June, joining the ranks of over 1,000 subvariants under the Omicron lineage.
What Does 'Variant Under Monitoring' Mean?
When a variant is marked as ‘under monitoring’, it signifies that it possesses traits that may pose a heightened threat compared to other circulating strains. As of late June, XFG is one of seven such variants actively observed for any concerning developments.
The Genetic Makeup of Stratus: A Recombinant Variant
XFG is intriguing since it's a recombinant variant, formed from the fusion of two subvariants: LF.7 and LP.8.1.2. Recombinants are denoted with an 'X' at the start of their names. This merging could potentially lead to properties that allow it to evade our immune defenses, making past infections and vaccinations less effective.
Spike Protein Changes and Mutation Insights
One of the primary concerns with XFG is the four significant mutations found in its spike protein—an essential element that enables the virus to latch onto human cells. Early laboratory tests suggest a concerning trend: antibody effectiveness against XFG might be nearly half as effective compared to other subvariants, raising alarms about potential spread.
Where is Stratus Spreading?
The emergence of XFG was first noted on January 27, and by June 22, researchers had documented over 1,648 sequences from 38 countries, making up 22.7% of the global cases. This is a substantial uptick from just 7.4% four weeks earlier. XFG is rapidly closing in on the dominance held by another variant, NB.1.8.1—formerly in the lead.
Global Impact: Countries Most Affected
Current data reveals that India is grappling with the highest detection rates of XFG, surpassing 50%, with Spain at 42%, and the UK and US tallying over 30%. In Australia, although NB.1.8.1 is still the major variant, XFG is making strides, constituting about 5% of cases.
Common Concerns: Severity and Symptoms
Naturally, people are wondering: Is XFG more dangerous? What symptoms should we watch for? While some reports suggest a higher likelihood of causing 'hoarseness' or a raspy voice, conclusive evidence about its severity or transmissibility compared to other variants is still elusive.
Will Vaccines Stand Up Against XFG?
As the virus evolves, so do our vaccines. The latest updates target emerging subvariants, including the recent JN.1 variant that Stratus descends from. Fortunately, available vaccines are believed to still offer strong protection against XFG, especially against severe cases.
The Vaccination Dilemma
Despite the ongoing risk posed by XFG, vaccination rates remain troublingly low in regions like Australia, especially among the elderly, with only 32.3% of those aged 75 and over having received a booster in the past six months. Health officials stress the importance of getting vaccinated and taking precautions.
Final Thoughts: The WHO's Assessment
As we closely monitor the situation with XFG, the WHO currently judges the global risk posed by this subvariant to be low. The standard advice remains: Get vaccinated, maintain good health practices, and be alert for new information on evolving COVID-19 variants.