New Delhi, 19 June 2025: A new sub-variant of COVID‑19, officially known as NB.1.8.1 and informally dubbed “Nimbus,” is rapidly gaining ground in the United States. It now accounts for a significant percentage of COVID cases across the country as of early June 2025. Global health agencies have placed this variant under monitoring due to its rapid spread and unusual symptom profile.
Alarming Symptom: ‘Razor Blade Throat’
What truly sets Nimbus apart is a distinctive and painful symptom described by many as a “razor blade throat.” Patients have reported a sore throat so severe that it feels like swallowing broken glass or metal shards. While sore throats are common with upper respiratory infections. The intensity and consistency of this particular symptom with Nimbus have drawn the attention of doctors and health officials alike.
Geographical Spread and Transmission Patterns
Nimbus has been identified across multiple U.S. states including California, Washington, Virginia, New York, Massachusetts, and Connecticut. Wastewater surveillance and genomic sequencing have confirmed its spread in both urban and rural regions. Beyond the U.S., the variant is also circulating in several parts of Southeast Asia and the Mediterranean, suggesting international transmission routes.
Severity: More Painful, But Not Deadlier
Despite its unpleasant throat symptoms, current data suggests that Nimbus is not causing more severe illness or higher hospitalization rates than other Omicron sub-variants. Most cases have been mild to moderate, especially among vaccinated individuals. However, like previous variants, it can still pose serious risks to elderly people, the immunocompromised, and those with chronic conditions.
Existing Vaccines and Treatments Still Work
Preliminary evidence indicates that existing COVID-19 vaccines continue to provide protection against severe illness caused by Nimbus. Booster doses are especially effective at reducing the risk of hospitalization. Antiviral medications, such as Paxlovid, remain useful tools for treatment and are being recommended for high-risk individuals who test positive.
Symptoms Overview: Familiar With an Edge
The most widely reported symptom of Nimbus is the razor-sharp throat pain. But other common signs include fever, fatigue, nasal congestion, dry cough, and muscle aches. Some people also report gastrointestinal discomfort. In many ways, it resembles previous Omicron symptoms but with a heightened focus on the upper respiratory tract, particularly the throat and voice box.
What You Should Do if You Get It
If you experience sudden and severe throat pain accompanied by other cold-like symptoms, you should:
- Take a rapid COVID test.
- Seek antiviral treatment early, especially if you’re in a high-risk group.
- Stay home and isolate to avoid spreading the virus.
- Use throat lozenges, warm fluids, and over-the-counter pain relief to manage discomfort.
- Stay well-hydrated and monitor your symptoms.
Preventive Precautions Remain Crucial
Health experts continue to recommend:
- Staying up to date with COVID vaccinations, including boosters.
- Wearing masks in crowded or poorly ventilated areas.
- Practicing good hand hygiene.
- Avoiding close contact with sick individuals.
- Testing promptly if symptoms appear.
Nimbus has raised concerns mainly due to its unusually painful sore throat symptom. But it does not appear to be more dangerous than previous variants. Vaccination remains the most effective way to prevent serious outcomes, and early testing and treatment can help manage symptoms. While not a cause for panic, this new variant is a reminder that COVID-19 continues to evolve—and so must our awareness and response.
