As COVID-19 continues to evolve, two new Omicron subvariants NB.1.8.1 (nicknamed Nimbus) and XFG (Stratus) have emerged on the global radar, prompting health authorities to closely monitor their spread. Though these strains don’t appear more dangerous than previous ones, they do bring subtle changes in symptoms, with some distinctive signs worth noting. Here is a detailed look at the latest known symptoms, what experts are saying, and how to protect yourself.
Overview of the New Strains
The World Health Organization has categorized Nimbus (NB.1.8.1) and Stratus (XFG) as variants under monitoring due to their rapid spread across multiple countries
Nimbus (NB.1.8.1)
- Called Nimbus informally by researchers
- Reports of a severe sore throat described as razor blade throat
- Common flulike symptoms include fever, fatigue, dry cough, congestion, and muscle aches
- Gastrointestinal issues such as diarrhea, nausea, vomiting, and even heartburn have been reported in a minority of cases
- Global distribution includes Asia, US, Canada, Europe, Australia, and more
Stratus (XFG)
- Recombinant variant XFG, called Stratus
- Notable symptom of hoarseness or a raspy voice, in addition to sore throat, dry cough, fever, muscle aches, and fatigue
- Emerging dominance in Asia and spreading globally
- No signs yet of increased severity compared to earlier Omicron strains
How These Symptoms Compare to Other Variants
While new variants still cause familiar things like cough, fever, fatigue, and sore throat, Nimbus’s extreme throat pain and Stratus’s hoarseness stand out as unusual. In contrast, earlier Omicron strains often produced more nasal congestion and loss of smell. These new features suggest slight changes in where and how the virus affects the respiratory tract
Severity and Transmission
- Neither variant has shown higher rates of hospitalization or more serious disease
- Both appear to evade immunity more effectively, making reinfection more likely
- Rapidly spreading: Nimbus represents around 37% of US wastewater-based cases; XFG ~9%
Timeline of Symptoms and Incubation
With Omicron descendants, symptoms typically appear 2 to 14 days post-exposure, often within 3 to 5 days
Selfcare and When to Seek Help
- Rest, stay hydrated, treat fever or pain with paracetamol or ibuprofen
- Soften sore throat with warm drinks, lozenges, honey but not for infants under 1
- If experiencing severe symptoms difficulty breathing, chest pain, confusion seek medical attention promptly
- Isolate at least 5 days, or more if symptoms persist follow local health guidelines
Protection and Vaccination
Existing vaccines remain effective at preventing severe disease, hospitalization, and death from these new subvariants
Testing and Detection
Standard rapid antigen or PCR tests still detect infection with these variants, even though they can’t identify which specific subvariant is present
Why Continued Vigilance Matters
These new variants highlight that COVID-19 has not disappeared it is continuing to evolve. Health officials emphasize ongoing surveillance, up-to-date vaccination, and basic prevention measures such as mask-wearing in crowded indoor spaces
Who Should Be Especially Careful
- The elderly and immunocompromised
- Pregnant individuals
- Those with chronic health conditions
- Caregivers and healthcare workers
Bottom Line
The Nimbus (NB.1.8.1) and Stratus (XFG) variants of COVID-19 are marked by unusual symptoms especially severe throat pain or hoarseness but appear no more dangerous than earlier Omicron strains. With vaccines still protecting against serious illness, staying informed, isolating when sick, and following health advice remains key to staying safe. Keep an eye on symptoms, test if needed, and consult a healthcare provider if you have concerns or persistent illness.
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