Children younger than 5 years old. The risk for severe complications from seasonal influenza is highest among children younger than 2 years old
Persons aged 65 years or older
Persons younger than 18 years who are receiving long-term aspirin therapy
Adults and children who have chronic pulmonary (including asthma), cardiovascular (except hypertension), hepatic, hematological (including sickle cell disease), neurologic, neuromuscular, or metabolic disorders (including diabetes)