Essentially "everyone 6 months and older should get a flu vaccine each year... it’s especially important that certain people get vaccinated either because they are at high risk of having serious flu-related complications or because they live with or care for people at high risk for developing flu-related complications," www.cdc.gov.
Who are at high risk of having serious flu-related complications?:
- Asthma (even if it’s controlled or mild)
- Chronic lung disease (such as COPD and cystic fibrosis)
- Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)
- Blood disorders (such as sickle cell disease)
- Kidney disorders
- Liver disorders
- Weakened immune system due to disease or medication (such as people with HIV or AIDS, or cancer, or those on chronic steroids)
- People who are morbidly obese
- People who live in nursing homes and other long-term care facilities
- People who live with or care for those at high risk for complications from flu