What Is the Razor Blade Throat COVID Variant?
The “razor blade throat” COVID symptom refers to an unusually severe sore throat associated with the NB.1.8.1 subvariant, also called the Nimbus variant. First observed in the U.S. in mid-2025, this strain appears to target the upper respiratory tract, especially the oropharynx, causing intense pain described by patients as “swallowing glass.” According to physicians in Texas and California, it’s now considered a key early sign of NB.1.8.1 infection.
NB.1.8.1 is a recombinant subvariant of Omicron and has gained traction due to its unique symptom profile. Unlike previous strains where throat irritation was mild or late-stage, NB.1.8.1 tends to trigger oropharyngeal inflammation early in the infection cycle. This makes diagnosis more straightforward in some cases, especially when paired with headache and fatigue.
The term “razor blade throat” was coined informally by patients and ER staff due to the stabbing, raw pain reported. From a medical standpoint, this pain may be linked to viral replication concentrated in the oropharyngeal tissue, where inflammation activates nerve endings more acutely. While still classified under mild-to-moderate COVID severity, the distinct throat pain has prompted concern for misdiagnosis as strep or flu.
Why This Symptom Is Causing Concern
The razor blade throat symptom is causing concern because it presents earlier, feels more severe, and disrupts daily life more than sore throats from past COVID variants. In contrast to the scratchy throat reported during early Omicron waves, NB.1.8.1’s sore throat is often the first and most dominant symptom, leading some patients to delay testing or mistake it for a bacterial infection. This delay can result in unnoticed spread of the virus.
One reason for the heightened concern is symptom severity. Patients describe the pain as sharp, constant, and debilitating, often interfering with eating, sleeping, or speaking. ER physicians report cases where patients initially assumed they had strep throat or tonsillitis due to the level of discomfort. This misidentification not only slows diagnosis but also increases the risk of community transmission if individuals aren’t isolating promptly.
Another issue is the psychological impact of such intense symptoms. For many, a sore throat that feels like “swallowing glass” adds anxiety or urgency that wasn’t common with more muted symptoms seen in recent subvariants. While NB.1.8.1 does not appear to cause more hospitalizations than prior strains, its symptom presentation is trickier, severe enough to alarm, yet not always recognized as COVID until confirmed via testing.
Symptoms of the NB.1.8.1 COVID Variant
The NB.1.8.1 subvariant, nicknamed the Nimbus variant, is associated with a distinct symptom profile led by the “razor blade throat.” Unlike milder sore throats seen in prior Omicron strains, this variant causes intense oropharyngeal pain early in the infection. Common co-occurring symptoms include nasal congestion, headache, fatigue, and fever, which overlap with traditional COVID signs but present with greater discomfort and earlier onset.
Most patients infected with NB.1.8.1 report a sore throat as their first and most pronounced symptom, sharp, raw, and worsening with swallowing. In clinical observations, this sore throat may last 3 to 5 days, peaking within the first 48 hours. Fatigue and headache often accompany it, suggesting a strong immune response early in the infection process, possibly linked to the virus’s replication in the throat and upper respiratory tract.
Other symptoms reported include nasal congestion, loss of appetite, and low-to-moderate fever. While the variant does not appear to increase severity in terms of hospitalizations, the symptom experience is more intense. This leads some patients to seek care sooner or request antibiotics, despite the illness being viral. Understanding this symptom cluster helps differentiate NB.1.8.1 from seasonal flu or allergies, especially relevant during summer 2025 respiratory spikes.
How the “Nimbus” Variant Is Spreading
The NB.1.8.1 subvariant, known as the Nimbus variant, is spreading rapidly in parts of the U.S. and abroad, Recent CDC data estimating it now accounts for roughly 37% of COVID cases nationwide as of early June 2025. Initial surges were reported in California and Texas, with subsequent clusters in Asia, particularly China, suggesting global transmissibility. While the variant’s severity appears consistent with other Omicron descendants, its rapid spread and unique symptom profile have drawn attention.
Epidemiologists note that NB.1.8.1 is not necessarily more dangerous but is more transmissible, especially in indoor, close-contact environments. The sore throat symptom may contribute to under-testing early on, as people often assume it’s a cold or allergy-related. That delay in isolation could help explain its swift spread across states. Wastewater surveillance has also confirmed rising viral loads in several metropolitan regions, matching clinical case trends.
Despite high case counts, current data suggests hospitalization and mortality rates remain in line with other recent subvariants. However, the speed of transmission, and the discomfort of symptoms, has prompted renewed calls for vigilance. Public health officials are especially monitoring its impact in unvaccinated populations and those with waning immunity from prior boosters.
What Doctors and Experts Are Saying
Doctors and infectious disease experts are emphasizing that the razor blade throat symptom should not be ignored, it’s quickly becoming a clinical red flag for the NB.1.8.1 subvariant. According to Dr. Peter Chin-Hong, an infectious disease specialist at UCSF, “This kind of sore throat is unusually severe and should prompt immediate COVID testing, especially if accompanied by fatigue or congestion.” Many ER physicians report that patients with this symptom are often shocked to learn it’s COVID, not strep.
Virologists suggest the intense throat pain is likely due to virus replication focused in the oropharynx, a pattern observed in other upper respiratory variants but not typically this extreme. This may explain why some patients experience the sensation of “swallowing razor blades” even before other symptoms emerge. Medical experts now view this as a distinguishing feature of NB.1.8.1, which could help differentiate it from flu or RSV in clinical settings.
Public health agencies have not yet issued variant-specific guidelines but encourage testing at the first sign of unusual throat pain. Experts agree that early identification and isolation are crucial for slowing spread. As more data emerges, the sore throat could become a leading diagnostic cue, particularly during the summer respiratory virus season when symptoms can easily be confused with allergies or bacterial infections.
What To Do If You Have Razor Blade Throat
If you’re experiencing a severe sore throat that feels like “swallowing glass,” doctors recommend testing for COVID-19 immediately, especially given the rise of the NB.1.8.1 variant. Over-the-counter remedies like acetaminophen, throat sprays, lozenges, and warm fluids can help manage pain, but they won’t shorten the illness itself. Confirming COVID status is key for preventing further spread and guiding treatment decisions.
The CDC currently advises testing if you have any unusual or worsening symptoms, and this includes excruciating sore throat without a known bacterial cause. Rapid antigen tests are generally reliable within the first few days of symptom onset. If positive, isolate for at least 5 days and wear a mask for 10 days when around others, especially indoors. If symptoms worsen or breathing becomes difficult, seek medical care promptly.
On average, the razor blade throat symptom lasts 3 to 5 days, often improving before other symptoms resolve. Fatigue and congestion may linger slightly longer. Most people recover at home without complications, but hydration and rest are critical. If you’re unsure whether your pain is COVID-related, it’s best to test rather than wait, especially during peak variant waves like summer 2025.
Comparison: Razor Blade Throat vs Other COVID Symptoms
The “razor blade throat” symptom sets NB.1.8.1 apart from earlier COVID variants due to its intensity and early onset. While Delta was known for chest tightness and Omicron for mild, scratchy throats, NB.1.8.1 produces sharp, localized pain in the oropharynx that many patients say feels worse than strep. This makes it easier to misidentify, and potentially underreport, without timely testing.
Unlike variants that featured loss of smell, shortness of breath, or gastrointestinal symptoms, NB.1.8.1’s symptom cluster centers more on upper respiratory pain and fatigue. It’s not that other symptoms are absent, they still occur, but the sore throat is disproportionately more prominent. This suggests the virus is replicating more heavily in the throat region early on, a theory supported by viral load studies in recent cases.
What makes NB.1.8.1 stand out isn’t a higher severity overall, but its distinct diagnostic signal. A sore throat this painful appearing as the first symptom is rare across respiratory illnesses. Recognizing this difference helps distinguish it from seasonal colds or flu, especially when fever is absent. For clinicians and patients alike, the nuance lies not in what the symptoms are, but how and when they show up.
FAQ: Razor Blade Throat and COVID
Can COVID feel like razor blades in the throat?
Yes. With the NB.1.8.1 (Nimbus) variant, many patients report a sore throat so severe it feels like “swallowing razor blades.” This is due to intense inflammation in the oropharynx caused by early viral replication.
How long does razor blade throat last?
On average, the severe throat pain lasts 3 to 5 days, often peaking within the first 48 hours. It typically improves before other symptoms like fatigue or nasal congestion resolve.
Is razor blade throat dangerous?
While painful, the symptom itself is not typically dangerous. However, it may indicate active viral shedding and should prompt testing and isolation to prevent further spread.
Should I go to the ER for severe throat pain?
If the pain prevents swallowing fluids or breathing becomes difficult, seek emergency care. Otherwise, most cases can be managed with rest, hydration, and over-the-counter remedies at home.
Trusted Resources
World Health Organization (WHO)
