Across the United Kingdom and much of Europe, a familiar sound is echoing through crowded buses, schools, and office corridors: the cough. But this autumn, it’s not just the common cold making the rounds. COVID-19 and flu are both actively circulating, with experts warning that new variants—dubbed Stratus and Nimbus—are driving a fresh surge in cases, hospital admissions, and, for some, confusion about what’s making them ill.
According to the latest data from the UK Health Security Agency (UKHSA), COVID-19 activity remains at medium levels as of October 20, 2025, though it’s shown a slight decrease compared to the previous week. However, flu cases are on the rise, particularly among children and young adults. Dr. Conall Watson, a consultant epidemiologist at UKHSA, cautions, “Anyone experiencing flu or COVID-19 symptoms, including high temperature, cough and feeling tired or achy, should try to minimise contact with others, particularly with those who may be vulnerable.” He adds, “If you have symptoms and need to leave the house, our advice remains that you should consider wearing a face covering.”
This guidance is more relevant than ever, as the new Stratus (XFG and XFG.3) and Nimbus (NB.1.8.1) strains have become dominant. Between September 29 and October 5, 2025, Stratus accounted for about 35% of sequenced COVID cases in England, while Nimbus made up 11%. The World Health Organization (WHO) has classified both as “variants under monitoring,” signaling that scientists are watching for any signs of increased risk, but so far, there’s no evidence they cause more severe illness than previous variants.
Yet, these new strains come with some unusual and, frankly, uncomfortable symptoms. The most commonly reported sign of Stratus is a sudden hoarse voice. George Sandhu, deputy superintendent pharmacist at Well Pharmacy, explained to Sun Health, “One distinctive symptom which many people have noticed before testing positive for the latest Covid variant is a hoarse voice.” Meanwhile, the Nimbus strain has been linked to a sore throat so intense, it’s been described as a “razor blade throat.”
Social media has amplified reports of other odd symptoms, too. One US woman, Nev, shared her experience on TikTok after catching the virus in late August. She described her symptoms: “When I went to bed that night, my teeth were hurting, my jaw was hurting, and my head hurt really bad.” Her story struck a chord, with others chiming in about similar experiences, especially the unusual teeth and jaw pain. One commenter wrote, “The teeth pain was terrible! Never had that symptom til this time around.”
Common COVID symptoms continue to overlap with those of flu and seasonal colds, making it hard to tell them apart. The NHS lists twelve key signs: high temperature or chills, a new continuous cough, loss or change to your sense of taste or smell, shortness of breath, fatigue, body aches, headache, sore throat, blocked or runny nose, loss of appetite, diarrhea, and nausea or vomiting. Dr. Amir Bhogal, a superintendent pharmacist, notes, “A cold usually tends to be congestion-related. Whereas flu tends to be more heavy on the fever, chills, aches and tiredness. COVID is, most commonly, everything all at once.”
With so much overlap, testing remains the most reliable way to know what you’re dealing with. COVID tests are still free on the NHS for those eligible for treatment and are widely available for purchase at pharmacies and online retailers. Bhogal warns against ignoring a lingering cough or sore throat, saying, “Anything longer than three weeks after symptoms have subsided – particularly if it’s associated with a hoarse voice – should be checked by a doctor.” He points out that some patients initially diagnosed with a long COVID cough were later found to have whooping cough or a secondary bacterial infection.
While the severity of illness from Stratus and Nimbus appears similar to earlier COVID variants, the UKHSA emphasizes that the virus “is still causing severe illness, hospitalisations, and deaths – particularly among those with a weakened immune system and those 75 years old and over.” The agency reiterates that “autumn COVID-19 vaccines are our best defence against serious illness.”
Prevention remains a community effort. COVID experts across the European Union are now urging a return to face masks as cases spike. In Switzerland, Tanja Stadler, chair of the Swiss Confederation’s Covid scientific task force, told SonntagsZeitung, “In crowded, enclosed spaces, such as public transportation, [wearing a mask] is advisable for vulnerable people—those over 65 or those with compromised immune systems. Even those who aren’t vulnerable can protect themselves from troublesome infections and, at the same time, show solidarity with others.”
Marcel Tanner, professor emeritus of public health at the University of Basel, echoed this advice, saying, “After everything we’ve learned, it would be logical for anyone with a cold to wear a mask, at least on public transportation.” The message is clear: while mask mandates may not be in place, personal responsibility and solidarity are crucial, especially as the autumn season brings increased respiratory illnesses.
The WHO has deemed the Stratus strain a “low risk” globally, noting, “XFG is growing rapidly compared to co-circulating variants globally. However, XFG exhibits only marginal additional immune evasion over [other variant] LP.8.1.” The organization adds that, although cases and hospitalizations are rising in some regions, “there are no reports to suggest that the associated disease severity is higher as compared to other circulating variants.” Still, Stratus may be more adept at evading antibodies from previous infections or vaccinations, due to specific mutations in its spike protein, as Dr. Kaywaan Khan of Hannah London Clinic explained to Cosmopolitan UK.
With testing no longer required for most, the NHS now recommends following a “five-day rule” for those who test positive: isolate as much as possible for five days after your positive result. Children and young people should isolate for three days, as they tend to be contagious for a shorter period. The guidance also urges people to avoid contact with older individuals or anyone with a weakened immune system if they feel unwell, and to stay home if they have a fever or are unable to carry out normal activities.
As always, simple measures help prevent the spread of both COVID and flu: regular handwashing, covering your mouth and nose when coughing or sneezing, using and disposing of tissues properly, and ensuring good indoor ventilation. For those eligible, taking up the seasonal COVID vaccination remains the best protection against serious illness.
As the UK and Europe brace for another challenging winter, the message from health authorities and experts is one of vigilance, self-care, and community-mindedness. Whether it’s a hoarse voice, a razor-sharp sore throat, or just feeling “off,” knowing the signs—and taking action—can help protect not just yourself but those around you.
