In the closing months of 2025, two new Covid-19 variants—nicknamed Nimbus (NB.1.8.1) and Stratus (XFB)—have become the latest focus of attention in both the UK and the US. While these variants are not thought to cause more severe illness than earlier strains, they are spreading quickly and producing unusual symptoms that have doctors and patients taking notice. The most distinct symptom reported so far is an extremely painful sore throat, often described as feeling like swallowing “razor blades.” This, along with the usual cough, fatigue, and runny nose, has become one of the key indicators of infection.
In the UK, data from the Health Security Agency (UKHSA) shows infection positivity rates have increased from 7.6% to 8.4% in a single week. Hospital admissions have also edged upward, from 2.0 to 2.73 per 100,000 people. Although these numbers are far below the pandemic peaks of previous years, the steady rise has health officials concerned about additional strain during the winter months, when flu and other respiratory illnesses are already common.
In the US, CDC wastewater tracking—a reliable early indicator of Covid spread—shows moderate levels nationwide, though several states are now recording very high concentrations of the virus, especially in the Northeast. This trend suggests that infections are climbing on both sides of the Atlantic.
Dr. Aaron Glatt, an infectious disease expert in the US, has noted that patients with these new variants often report sore throats of unusual severity. “Some describe it as if their throat is lined with razor blades,” he said. While throat pain has been a known Covid symptom since early in the pandemic, the level of discomfort linked to Nimbus and Stratus seems particularly intense.
Symptoms and Transmission
Aside from sore throats, patients with the new variants continue to experience the standard range of Covid symptoms—fever, headache, nasal congestion, cough, and fatigue. However, the sharp, croaky throat and even temporary voice changes are standing out as unique features of these new strains.
Experts emphasize that while these symptoms can be very unpleasant, there is no evidence that Nimbus or Stratus cause more serious disease than earlier forms. The main concern is how efficiently they spread. Genetic mutations have made them highly transmissible, meaning they can move through communities faster, which could still burden hospitals even if most cases remain mild.
Health Advice and Vaccination
Health agencies are responding by intensifying vaccination campaigns. In the UK, the winter rollout is already underway, prioritizing over-75s, care home residents, pregnant women, immunocompromised people, and children. Covid and flu vaccines are being offered together in many places, with flu nasal sprays now available to toddlers in community pharmacies.
In the US, vaccination efforts continue but with lower public participation than in previous years. Some private pharmacies are now offering Covid boosters independently, with prices reported as high as £99 ($134).
Public health guidance remains consistent: if you have symptoms, stay home if possible, avoid contact with vulnerable individuals, and wear a mask in crowded spaces. Anyone with a high fever or who feels unwell enough to miss work should assume they may be contagious. Although free testing is limited, rapid test kits are still available for purchase in pharmacies.
Vaccine Controversy
The renewed rise in cases has coincided with a wave of misinformation following a controversial South Korean study published in Biomarker Research. The study suggested that Covid vaccines “might raise the risk of cancer,” though it provided no scientific mechanism or credible evidence to support the claim.
Health experts around the world have dismissed the study as misleading, pointing out that no reliable data links Covid vaccination to cancer. Researchers note that vaccine effects on DNA repair and tumor suppression have been extensively studied, with no harmful pathways identified. Professor Lawrence Young, a virologist from the University of Warwick, called the paper’s conclusions “hugely overblown.”
The situation echoes recent misinformation spread by cardiologist Dr. Aseem Malhotra, who falsely implied Covid vaccines could be connected to cancers in members of the British royal family. His claims were quickly discredited by scientists and distanced by the political party that hosted his talk. The overwhelming scientific consensus remains unchanged: Covid vaccines are safe, effective, and a key tool in preventing serious illness and death.
Living With Covid
Nearly six years into the pandemic, most societies have shifted toward “living with Covid” rather than trying to eliminate it entirely. Governments no longer impose widespread lockdowns; instead, individuals are encouraged to take responsibility for limiting transmission. That means staying home when sick, wearing masks in crowded places, and keeping vaccinations up to date.
Still, maintaining public vigilance has become increasingly difficult. After years of constant pandemic news, many people are simply tired. Yet Covid remains an evolving virus that continues to mutate. Nimbus and Stratus are not catastrophic, but they are a clear reminder that the virus hasn’t disappeared—it’s simply entered a long-term phase of coexistence.
The Bigger Picture
The rise of Nimbus and Stratus underscores a broader truth: pandemics rarely end suddenly. Instead, they fade gradually, with waves of resurgence caused by new mutations. For already stretched healthcare systems, even a moderate increase in hospitalizations can create serious challenges. And for families, even a “mild” Covid infection still disrupts work, school, and daily routines—especially for those caring for vulnerable loved ones.
These new variants highlight the need for continued caution, clear communication, and scientific trust. Vaccines, masks, and responsible behavior remain the most effective defenses against the virus. At the same time, fighting misinformation is equally vital, as false claims about vaccine risks can be as harmful as the virus itself.
Conclusion
The new Covid-19 variants, Nimbus and Stratus, are spreading rapidly in both the UK and the US. They bring with them distinctive symptoms—especially the severe, razor-blade-like sore throat—and high transmissibility, even if they don’t appear more deadly. Health authorities are urging people to stay alert, get vaccinated, and take precautions during the winter season.
Covid may no longer dominate global headlines as it once did, but it continues to evolve, adapt, and remind us of its presence. The story of Nimbus and Stratus isn’t about fear—it’s about preparedness. The world has learned to live with the virus, but vigilance and science remain our strongest allies in keeping it under control.