Influenza is a viral disease that causes widespread illness every year.
Immunising people who are at risk of complications from the flu is the most important way we have to reduce the number of flu infections and deaths.
Influenza immunisation is recommended for people in known high-risk groups.
People who work or live with people who are at risk of serious complications should also be immunised to avoid spreading the flu.
The vaccine cannot give you a dose of flu because it does not contain any live virus.