As pollen counts soar and hay fever season hits the UK, a sneaky new Covid variant dubbed “Nimbus” (NB.1.8.1) is muddying the waters. With symptoms eerily similar to allergies, this fast-spreading strain is sending more Brits to the hospital—and it’s easy to mistake for a seasonal sniffle. Here’s what you need to know about Nimbus, how it stacks up against hay fever, and why vigilance is key.
A Tricky New Variant
Nimbus, a mutated descendant of the Omicron variant, has been making waves since its detection in January 2025. By late April, it accounted for 10.7% of global Covid cases, up from just 2.5% a month earlier, according to the World Health Organization (WHO), which has labeled it a “variant under monitoring.” In the UK, the strain is gaining ground, with 13 confirmed cases in England and small clusters in Northern Ireland and Wales.
The UK Health Security Agency (UKHSA) reports a 9.4% spike in Covid-related hospital admissions, with 947 patients admitted in the week ending May 31, 2025. Urban hubs like Birmingham, London, and Manchester are hit hardest, but rural areas aren’t immune. While researchers are still probing its transmissibility, early data suggests Nimbus spreads more easily than its predecessors, thanks to tweaks in its spike protein that may help it dodge immunity.
Covid vs. Hay Fever: A Symptom Showdown
Nimbus’s symptoms overlap with hay fever, making it a diagnostic headache during peak pollen season (March to September). Both can cause:
-
Sneezing
-
Runny or blocked nose
-
Headaches
-
Loss of smell
But there’s a catch: hay fever is an allergic reaction, while Covid is a viral infection that can knock you out for days—or worse. Dr. Luke Powles, Associate Clinical Director at Bupa, told The Sun, “This can make it harder to tell if sniffs and sneezes are being caused by an allergy or an infection like coronavirus.”
How to Spot the Difference
The NHS and experts like Dr. Powles point to key clues to separate Covid from hay fever:
-
High Temperature: A hallmark of Covid, not hay fever. If your chest or back feels hot to the touch (no thermometer needed), it’s likely Covid.
-
Severe Loss of Taste/Smell: More common with Covid than hay fever, where smell loss is milder.
-
Gastrointestinal Issues: Nimbus can trigger nausea, vomiting, or diarrhea—symptoms absent in hay fever.
-
Fatigue and Body Aches: Covid often leaves you drained or shivering, while hay fever symptoms are typically lighter.
-
“Razor Blade” Sore Throat: A standout Nimbus symptom, described as a sharp, stabbing pain when swallowing, often with redness or swollen glands.
Dr. Naveed Asif, a GP at The London General Practice, emphasized this throat pain as a red flag, noting, “Symptoms can vary widely, so vigilance is key.”
Why It Matters
Though Nimbus doesn’t appear to cause more severe illness than other Omicron subvariants, its rapid spread is concerning. The WHO and UKHSA reassure that current vaccines remain effective against severe outcomes, but waning immunity from prior infections or shots could leave some vulnerable. With testing down since the pandemic’s peak, the true case count is likely higher than reported, fueling fears of a summer surge.
The risk of long Covid—lingering symptoms like fatigue or brain fog for weeks or months—also looms. The Independent reported that Nimbus’s ability to infect cells more efficiently could drive its spread, even if it’s not deadlier.
What to Do
Confused about your symptoms? The NHS advises:
-
Test if Possible: Lateral flow tests, available at pharmacies, can confirm Covid.
-
Stay Home if Sick: If you have a fever or feel unwell, avoid contact with vulnerable people. Wear a mask if you must go out.
-
Resume Normal Activities: Once your fever’s gone or you feel better, you’re likely clear to go.
Dr. Chun Tang, a GP at Pall Mall Medical, told The Independent, “NB.1.8.1 isn’t too different from Omicron, but its spike protein tweaks might make it spread more easily.” He urged vaccination, especially for those over 75, care home residents, or immunocompromised individuals, who are eligible for free jabs. UKHSA data shows spring 2025 boosters cut hospitalization risk by 45% compared to unvaccinated individuals.
A Call for Caution
With pollen and Nimbus both in the air, it’s easy to shrug off a sniffle as allergies—but that could be a mistake. An NHS spokesperson told The Sun, “If you’re unsure whether you’re suffering from hay fever or Covid, it’s wise to limit contact with others, especially those who are vulnerable.” As hospital admissions climb and summer travel peaks, staying vigilant could keep you and your loved ones safe. Grab a test, watch for that fever, and don’t let Nimbus sneak up on you.
