Risk groups for severe influenza

The influenza risk groups include people who are more likely than others to develop severe disease, resulting in hospitalisation or death, if they should be infected. The most recent published ECDC review indicated strong evidence for immunising two large risk groups:

• Older adults
• All persons (over six months of age) with chronic medical conditions

There is no sharp cut-off age for older adults, however many countries use the age of 65 years as a threshold, while other countries use younger ages.

The list of chronic medical conditions in patients often recommended for vaccination in EU/EEA Member States include diseases affecting the following:

• respiratory system e.g. asthma
• cardiovascular system e.g. coronary artery disease
• endocrine system e.g. diabetes
• hepatic system e.g. liver cirrhosis
• renal system e.g. chronic renal failure
• neurological/neuromuscular conditions e.g. parkinsonism

In addition to the above:

• any condition compromising respiratory functions e.g. morbid obesity (BMI > 40), physical handicap in children and adults
• immunosuppression due to disease or treatment including due to haematological conditions and HIV infection.

The WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommends that pregnant women be prioritised for immunisation above all groups. It also advises that the following groups be immunised:

• young children
• women up to 2 weeks postpartum
• individuals younger than 19 years of age on long-term aspirin or salicylate-containing medications
• older people
• individuals over six months of age with chronic conditions
• healthcare workers with patient contact

This guidance is described in a 2012 position paper and background paper on influenza vaccination, updating its 2005 guidance.

Read more on external websites

WHO Strategic Advisory Group of Experts on immunization

WHO vaccine position papers on Influenza