Understanding the Severe Sore Throat Symptom in COVID Variant Nimbus

As the COVID-19 variant NB.1.8.1, commonly referred to as Nimbus, accounts for approximately one-third of recent cases in the United States, a particular symptom has drawn heightened attention: a painful sore throat that some describe as feeling like 'razor blades.' This alarming symptom has been reported widely since the variant's emergence in May 2025, particularly noted in China before it spread globally. According to Dr. Matthew S. Kelly, MD, MPH, chief of infectious diseases at the University of Arkansas for Medical Sciences, the 'razor blade sore throat' has become a signature characteristic of this variant.

The Nimbus variant is a subvariant of Omicron, which has been the predominant strain of the virus since late 2021. Research indicates that Omicron variants are more likely to cause throat issues than prior versions of the virus. Dr. Peter Chin-Hong, MD, a professor of medicine specializing in infectious diseases at the University of California, San Francisco, notes that up to 70% of COVID patients have reported sore throats, often severe. He explains that changes in the virus and the immune response of the body contribute to this phenomenon.

The mechanism behind the severe throat pain involves the virus's interaction with ACE2 receptors, which are present in high concentrations in the upper airway. As Nimbus binds more effectively to these receptors, inflammation ensues as the body mounts its immune response, leading to symptoms including swelling, redness, and fluid buildup. Dr. Chin-Hong further elaborates that while the virus initiates the response, the pain is largely due to the inflammatory reaction rather than the virus itself.

To alleviate the discomfort associated with a sore throat, healthcare professionals recommend anti-inflammatory medications such as ibuprofen. Dr. Chin-Hong suggests that if swallowing pills is painful, liquid formulations may be beneficial. Additionally, topical numbing agents, like throat sprays containing benzocaine, can provide short-term relief. Warm or cold liquids, including herbal teas or ice pops, may also help soothe the throat, although no definitive studies exist to support these remedies.

It's important to note that antibiotics are ineffective against viral infections such as COVID-19, and overprescribing them poses risks, including the disruption of the microbiome. Similarly, corticosteroids should not be used as a quick fix for throat pain, as they may lead to prolonged symptoms and increase hospitalization rates, as reported in a 2025 study published in the Pharmacy journal.

For individuals experiencing a sore throat, it is advisable to conduct at-home COVID tests, as they remain effective for detecting the virus. Should symptoms worsen, particularly with signs of severe bacterial infection, medical consultation is essential. Dr. Chin-Hong encourages vigilance, particularly as cases of Nimbus may lead to a summer surge in infections. He advocates for vaccination, especially among older adults and those with chronic health conditions, as current vaccines are formulated to target Omicron variants.

The emergence of Nimbus highlights the ongoing evolution of COVID-19 and its variants, reminding the public of the importance of continued vigilance and proactive health measures. As the medical community continues to study and understand these variants, maintaining public awareness and access to effective treatments will be crucial in managing symptoms and preventing severe outcomes.