Table 1.

Guidelines for administering the influenza vaccine (adapted from recommendations of the Centers for Disease Control and Prevention¹)

Target groups	Timing and administration	Contraindications
People aged ≥65 years	Vaccine may be given any time during flu season	Previous anaphylactic reaction to vaccine, its components, or to eggs
Residents of nursing homes and chronic care facilities with chronic medical conditions	Optimal time for vaccination is from October through mid-November	Acute febrile illness
Adults and children who have chronic pulmonary or cardiovascular disorders	May be given concurrently with the pneumococcal vaccine and with other routine childhood vaccinations	Previous vaccine-related Guillain-Barre syndrome (vaccine may be justified in high risk patients)
Adults and children with other chronic medical problems such as diabetes, renal dysfunction, or immunosuppression	Only split-virus vaccines (known as “split”, subvirion”, or “purified-surface antigen” vaccines) should be administered to children (<12 years) due to their decreased potential for febrile reactions*
Children and teenagers receiving long-term treatment with aspirin should receive the influenza vaccine to reduce the risk of Reye's syndrome
Women in the 2nd or 3rd trimester of pregnancy during the influenza season	Should be administered intramuscularly: the deltoid is the preferred site in adults, the anterolateral aspect of thigh is preferred in infants and younger children
People who can transmit influenza to those who are at high risk (for example, healthcare providers, caretakers, household members)
Other groups to consider include people infected with HIV, travelers to regions with known epidemics, and anyone who wishes to reduce their risk of influenza illness

^*At recommended doses, the immunogenicity and side effects of split and whole virus vaccines are similar in adults.