This Topic Minibite covers immunisation against seasonal influenza (flu), and is based on guidance from the Department of Health's Immunisation against infectious disease — the 'Green Book' chapter 19, Influenza (updated in July 2008). 

Please note there is a separate CKS topic on influenza that covers the treatment of people with seasonal influenza and the post-exposure prophylaxis of people who have not been immunised against seasonal influenza.