Poster, 'Keep flu to yourself', illustration of ill person in bed closing door on busy next door room. 'Flu, one of 800 health education posters produced for the Central Council for Health Education (1927-69), Health Education Council (1969-87) and Health Education Authority (1987-2000).

Flu or influenza is caused by an infectious virus which easily spreads from person to person through infected droplets in coughs and sneezes. The poster lists symptoms, which include headaches, sore throat, shivering, aching limbs and tiredness. Once symptoms have appeared you should go to bed for at least 48 hours and stay away from other people. Flu is infectious one day before the symptoms appear and for two days afterwards.

Regular immunisation is recommended for those at high risk from flu, including people aged 65 years and over and those with a low immune system.