Influenza virus infection in infancy and early childhood.

Infants and young children have the highest influenza infection and hospitalisation rates in paediatrics. The immaturity of the infant's immune system and the absence of prior immunity and exposure to the virus are potential contributors. Although most children that suffer from influenza infection are otherwise healthy, an underlying chronic medical condition further increases the risk for complications. Annual immunisation with influenza vaccine is recommended for any child 6 months of age and older in whom prevention of disease is desirable, particularly for those with underlying medical conditions. Offering influenza vaccine to pregnant women who will deliver during the influenza season can potentially reduce the frequency and severity of influenza disease in infants less than 6 months of age. Family members, including other children and all other close contacts, should also receive influenza vaccine to reduce transmission to children at risk and infants in the first 6 months of life.