The currently available influenza vaccines give 70-80 per cent protection against infection with influenza virus strains well matched with those in the vaccine. Protection lasts for about one year. After immunisation, antibody levels may take up to 10-14 days to reach protective levels.

While influenza activity is not usually significant before the middle of November, the influenza season can start early and therefore the ideal time for immunisation is between September and early November. Within the UK, influenza immunisation is targeted at those individuals who are most at risk from the secondary complications of influenza infection.

They include:

• All those aged 65 years and over
• All those aged six months and over in the specified at-risk groups
• All pregnant women, irrespective of their stage of pregnancy
• Those living in long-stay residential care homes or other long-stay care facilities where rapid spread is likely to follow introduction of infection and cause high morbidity and mortality
• Those in receipt of a carer's allowance, or those who are the main carer of an elderly or disabled person whose welfare may be at risk if the carer falls ill
• Other people involved directly in delivering healthcare such that they and vulnerable patients are at increased risk of exposure to influenza
• Health and social care staff directly involved in the care of their patients or clients.

In 2013-2014, the universal childhood influenza vaccine programme with live attenuated influenza intra-nasal vaccine commenced across the UK, targeting children aged two to three years and varying pilot groups across the country. For the 2014/15 programme, all pre-school children aged two to five years and all primary schoolchildren are eligible for immunisation. Influenza vaccine uptake in 2013-2014 in England was similar to recent seasons in the elderly (73.2 per cent), in under 65-year-olds in a pre-defined clinical risk group (52.3 per cent) and in pregnant women (39.8 per cent), while an increase was seen in healthcare workers (54.8 per cent) compared to 2012-2013 (45.6 per cent).

In England, an uptake of 42.6 per cent and 39.6 per cent was achieved in two and three-yearolds respectively and an overall uptake of 52.5 per cent in the primary school age pilots targeting four to 11-year-olds. There is considerable scope to improve these levels through pharmacy services.