As the chill of autumn sets in and winter looms on the horizon, the UK finds itself once again in the grip of a seasonal surge in respiratory illnesses. According to the UK Health Security Agency (UKHSA), flu, COVID-19, and respiratory syncytial virus (RSV) are all circulating at heightened levels, with a spike in coronavirus cases and an uptick in hospital admissions for flu and RSV. While these viruses can strike at any time of year, their peaks typically coincide in the colder months, creating a perfect storm for the nation’s health services and vulnerable populations.
The landscape of winter bugs is complex, with multiple viruses—rhinovirus (the main culprit behind the common cold), adenovirus, human metapneumovirus (hMPV), and parainfluenza—also making their rounds. These pathogens often present with overlapping symptoms, making it tough for the average person to tell them apart. That’s why the UKHSA has issued fresh guidance to help the public navigate the differences and take steps to protect themselves and others.
“Last year’s flu vaccine had a significant impact on reducing severe illness, ranging from an almost 40% reduction in the number of those aged 65 and over being hospitalised, and a 75% reduction in those aged between two and 17 years,” the UKHSA stated in its recent explainer. The agency is urging everyone eligible to take up the offer of vaccination, especially as this season’s flu positivity rates have jumped from 1.9% to 3.3% in just a week, according to NHS England data. Nearly a million more people have already been vaccinated against flu this autumn compared to the previous year, reflecting both increased awareness and concern.
Flu itself is no ordinary cold. It’s a viral infection that hits the nose, throat, and lungs with force, often appearing rapidly and bringing extreme tiredness. The cold, by contrast, tends to creep in gradually, causing a runny nose, sneezing, watery eyes, and throat irritation, but rarely the fever or body aches that signal flu. The UKHSA warns that flu can lead to serious illness, particularly in children, older people, and those with long-term health conditions. Last winter, the UK saw around 8,000 deaths associated with flu—higher than the 3,500 recorded the previous year, but less than the 16,000 deaths during the 2022-2023 season.
Eligibility for the flu vaccine is broad: everyone aged 65 and over, those between 6 months and 65 with certain medical conditions, people living with immunocompromised individuals, frontline health and social care workers, all pregnant women, and children aged 2 and 3 years. School-aged children, from reception to year 11, are also offered a nasal spray vaccine through school immunisation teams.
COVID-19, meanwhile, continues to evolve. The latest figures reveal a 22.2% rise in confirmed cases across the UK in the week leading up to September 24, 2025, with deaths rising by 5.1%. Nearly 90% of new cases are now linked to two variants: NB.1.8.1 (‘Nimbus’) and XFG (‘Stratus’). According to virologist Lawrence Young of Warwick University, the Nimbus variant is spreading more easily, while Stratus has developed the ability to dodge antibodies from previous infections or vaccinations. Despite these changes, the UKHSA says there’s no evidence that these variants are causing more severe illness than their predecessors, though they continue to result in hospitalisations and deaths—especially among the elderly and immunosuppressed.
Symptoms of COVID-19 have shifted over time. “Today, many people now experience cold-like symptoms and some will also experience fever or chills, continuous cough, shortness of breath, tiredness, body aches, headache, sore throat, blocked nose, loss of appetite, nausea, diarrhoea, or change in sense of taste or smell,” the UKHSA explained. Some patients have reported a hoarse voice or a particularly painful sore throat, a symptom that’s been dubbed ‘razor-blade throat’ in the media. Vaccination remains the best defense, with over a million people receiving the COVID-19 vaccine so far this autumn. The vaccine is available to people aged 75 and over, care home residents, and those who are immunosuppressed.
As for the common cold, rhinovirus is the main offender. Its symptoms—blocked or runny nose, sneezing, sore throat, hoarse voice, cough, tiredness, and even a high temperature—develop over two to three days and can last longer in young children. The NHS highlights three main differences between colds and flu: flu symptoms come on fast, affect the whole body, and leave sufferers too exhausted to carry on as normal, while a cold tends to be milder and more localized to the nose and throat.
RSV is another major player in the winter illness line-up. It’s most common between November and February and can cause cough, wheezing, shortness of breath, tiredness, and fever. While many experience only mild symptoms, RSV can be especially serious for infants and older adults. The UKHSA notes that RSV causes bronchiolitis in infants, making it hard for them to breathe and feed. “You may see your baby experiencing fast or noisy breathing and being unsettled or difficult to comfort,” the agency advised. Bronchiolitis accounts for roughly 20,000 hospitalisations annually in children under one, and RSV leads to about 9,000 hospitalisations each year in people aged 75 and over in the UK.
To counter this, the NHS has introduced a vaccine for pregnant women—to protect newborns—and for adults aged 75 to 79. The vaccine isn’t currently recommended for those over 80, as there wasn’t enough data from clinical trials to confirm its effectiveness in that age group. When given during pregnancy, the RSV vaccine can reduce the risk of severe bronchiolitis in a baby’s first six months by 70%.
Other winter bugs, such as adenovirus, parainfluenza, and human metapneumovirus (hMPV), also circulate widely. These viruses usually cause mild, cold-like symptoms and can affect people of all ages. While they’re present year-round, they tend to spread more easily during the colder months and can sometimes lead to more severe respiratory infections in infants, older adults, and those with weakened immune systems.
With so many viruses circulating, how can people protect themselves and others? The UKHSA recommends staying at home if you have symptoms of flu or COVID-19 to protect the vulnerable. If you must go out while unwell, consider wearing a mask. Catching coughs and sneezes in a tissue, washing hands regularly, and opening windows when meeting others indoors can all help reduce the spread of respiratory infections. Some hospitals in England and Wales have even reintroduced mandatory face masks in certain departments to curb the rise in cases.
For those seeking more information, the UKHSA’s regular surveillance reports track the spread of these viruses, providing up-to-date data for the public and health professionals alike. The NHS website also offers guidance on telling the difference between colds and flu and advice on when to seek medical help.
As the nation braces for what could be a challenging winter, public health officials are clear: vaccination, vigilance, and common-sense hygiene are the best tools available. With the right precautions, the UK can weather the seasonal surge and protect its most vulnerable citizens.
