More than 2,460 patients were in hospitals with the illness each day at the start of the month.
An expert has revealed whether it is possible to contract flu more than once in a season, as the NHS recently reported its “busiest” winter week due to hospital admissions. Flu is just one of several illnesses that have been rife in the UK in recent months.
NHS England has also warned of high cases of COVID-19, respiratory syncytial virus (RSV), and norovirus, resulting in 98,101 patients in hospital each day for the week ending February 4. Although flu cases had reduced since January, more than 2,462 patients were still hospitalised with the illness each day that week, including 122 in critical care.
With all these illnesses going around it does feel like everyone has had something this winter. But are you able to get flu more than once in a season?
The flu season typically starts in October and lasts until around March or April. There are four types of flu, known as A, B, C, and D, but winter flu is usually caused by type A and B.
Flu A also has two variants that are common this time of year, H1N1 and H3N2. c, an infectious disease expert at Johns Hopkins Centre for Health Security, Dr Amesh Adalja, told US news site Koin that it is possible to have flu more than once in a season.
“You could get influenza (A) and then get influenza B, yes,” he said. “Or you could get infected very early in the season, and then by the end of the season your immunity wears off, so yes you can get infected more than once.”
In the US, influenza A has been the more dominant type this year, making up 2,642 of the 2,693 lab-confirmed cases of flu during the fourth week of 2025. However, in the UK, the NHS reported that cases of influenza B have increased in the fifth week of the year.
Among each of the main flu types, there are multiple strains, and the viruses continue to mutate. Cleveland Clinic infectious disease specialist Dr Donald Dumford, explained more.
He said: “If you got H1N1 first, then I expect you would be well protected for the H1N1 strain for the next several months. You could still get infected with another strain like H3N2.”
Flu symptoms come on very quickly and can include:
- A sudden high temperature
- An aching body
- Feeling tired or exhausted
- A dry cough
- A sore throat
- A headache
- Difficulty sleeping
- Loss of appetite
- Diarrhoea or tummy pain
- Feeling sick and being sick.
You should start to feel better by resting at home, drinking plenty of water, and taking ibuprofen or paracetamol. However, if your symptoms do not improve after seven days you should call 111.
The NHS warns: “Flu is very infectious and easily spread to other people. You’re more likely to give it to others in the first five days. Flu is spread by germs from coughs and sneezes, which can live on hands and surfaces for 24 hours.”
To reduce the risk of spreading flu you should:
- Wash your hands often with warm water and soap
- Cover your mouth and nose with a tissue when you cough or sneeze (if you do not have a tissue, cough or sneeze into the bend of your elbow, not into your hand)
- Bin used tissues as quickly as possible.
Try to stay at home and avoid contact with other people if you have a high temperature or you do not feel well enough to do your normal activities.