The World Health Organization has turned its analytical lens toward a fresh variant of COVID-19, tagged NB.1.8.1, colloquially known as Nimbus. This newly observed mutation, a spawn of the relentless Omicron lineage, was unearthed in late January and has stealthily infiltrated regions across Europe, the Americas, and the Western Pacific.
NB.1.8.1 appears to possess spike protein modifications that may supercharge its contagious nature. These spike proteins, akin to the virus’s lock-picking tools, assist in unlocking human cells, granting the virus entry.
While its footprint is expanding across the US, Canada, and at least 20 other nations, data suggests that it isn’t inflaming hospital beds or causing an alarming spike in sickness.
According to a risk profile released by the WHO, NB.1.8.1 accounted for 10.7% of sequenced infections in April — a jump from 2.5% just a month earlier. This incline, while sharp, has not been flagged as dangerous yet. The WHO has simply categorized the variant as “under monitoring” — a status short of serious concern, yet not entirely dismissible.
[WATCH] Minister of Health, Dr Aaron Motsoaledi has assured South Africans that the current Covid-19 variant, reported to be circulating in 22 countries is not a cause for concern. The new variant, Nimbus, is reported to have been detected in India, Europe, the US, Australia and… pic.twitter.com/IUYRt5taFi
— SABC News (@SABCNews) June 12, 2025
Current Landscape in the US: A Slow Reign
In American territory, most active COVID infections are still traced to the LP.8.1 strain — another branch from Omicron’s tree. But early indicators hint that NB.1.8.1 could soon supersede it as the dominant player.
CDC projections show NB.1.8.1 makes up roughly 37% of infections, running nearly neck and neck with LP.8.1 at 38%. Just a few weeks earlier, the same variant stood at a modest 15% — a notable leap suggesting quick dominance.
However, the CDC has signaled a caution: due to fewer lab-confirmed sequences being reported recently, their statistical confidence remains shaky, according to The Hill.
As per GISAID (Global Initiative on Sharing All Influenza Data), this evolving strain has been identified in 13 US states so far, including:
- California
- New York
- New Jersey
- Maryland
- Arizona
- Illinois
- Hawaii
- Massachusetts
- Ohio
- Rhode Island
- Vermont
- Virginia
- Washington
Risk Level & Immunity: An Equilibrium for Now
Presently, Nimbus does not signal an elevated global threat. The WHO affirms that current vaccines continue to shield effectively against grave illness and hospitalizations stemming from this strain.
“The vaccines we already have should still guard against both the symptoms and the severe impact caused by NB.1.8.1,” the WHO assessment notes. Despite parallel spikes in infections and hospital visits in certain nations where this variant is more rooted, there’s no verified data tying it to increased severity or mortality.
Lionel Gresh, WHO consultant, confirmed that while NB.1.8.1 is likely fueling rising cases in Canada, there’s been no notable shift in ICU usage, hospitalization rates, or COVID-linked deaths. Stability, not panic, remains the tone, as reported by The Hill.
What Are the Signs?
Symptoms tied to NB.1.8.1 echo those previously seen in the broader Omicron family. The well-known indicators include:
- Dry or persistent cough
- Recurrent fever
- Body exhaustion
- Muscle fatigue
- Stuffy nose or head congestion
- Headaches
- Nausea and occasional vomiting
- Loss of smell or taste
Gresh emphasizes a level-headed view: “Be as cautious as we’ve been with COVID in general. No need for more panic, nor less care.”
Interestingly, anecdotal reports from patients include a strange symptom dubbed “razor blade throat” — a sharp, painful feeling while swallowing. However, its exact linkage to NB.1.8.1 remains hazy. According to Ryan Gregory, a genome and evolution expert from the University of Guelph, this harsh sensation might originate from another respiratory bug rather than this particular variant, as per The Hill.
A Quiet Shifter, Not a Game Changer
While Nimbus (NB.1.8.1) subtly ascends the COVID stage, it’s not shaking the foundations just yet. For now, it stands as a variant to observe, not to fear. Stay informed, stay protected, and don’t let the name spook you — science, so far, has it under watchful control.