The following information relates to the 2025-26 flu season.
Flu can be very serious. It is caused by a virus, which is spread by coughs and sneezes. Symptoms of flu can be mild but can also lead to more serious illnesses such as bronchitis and pneumonia (lung infections), which may need treatment in hospital.
Flu is very infectious, and symptoms can come on very quickly. Symptoms of flu include a high temperature, tiredness and weakness, headache, aches and pains and a cough. More information about flu is available from NHS 111 Wales - Health A-Z : Flu (external site)
There are outbreaks of flu most winters, especially in hospitals and care homes.
In a normal winter, thousands of people will die from flu-related illnesses in the UK. Having a flu vaccine every year is one of the best ways to help protect against flu.
There are cases of flu every winter. It is very important to get your flu vaccine every year if you are eligible.
Flu vaccines are quick and very safe and could prevent weeks of serious illness.
If you have any questions or want more information, you can go to 111.wales.nhs.uk (external site), talk to your doctor or nurse, or contact NHS 111 Wales by calling 111.
To find out more about the vaccine, including its contents and possible side effects, go to www.medicines.org.uk/emc (external site). You will need to enter the name of the vaccine in the search box.
You should report suspected side effects online at www.mhra.gov.uk/yellowcard (external site), by downloading the Yellow Card app, or by calling 0800 731 6789 (Monday to Friday, 9am to 5pm).
The schedule showing which immunisations are routinely offered in Wales is available from phw.nhs.wales/CompleteSchedule