Influenza Vaccines for the Future

Abstract

Ecological and active population-based surveillance studies have clearly shown the large burden of influenza disease in children, both in hospital and outpatient settings. Mortality and encephalitis due to influenza have also been reported. Two vaccines are licensed for use in children; trivalent inactivated and live attenuated vaccines. Both have been shown to be efficacious for the prevention of clinically and laboratory-confirmed influenza. In recent comparative trials in young children, live attenuated vaccines were shown to be more effective than trivalent inactivated vaccines for the prevention of laboratory-confirmed influenza. However, episodes of wheezing were increased in the youngest children receiving live attenuated vaccine. Trivalent inactivated influenza vaccine has an excellent safety profile and has been mainly associated with local pain and tenderness at the injection site. Vaccine efficacy for the inactivated vaccine has been shown to be greater in older children. Increased use of either influenza vaccine has the potential to reduce the disease burden in children and to extend herd protection to those who are not vaccinated.