Immunizing children and adolescents with inactivated influenza vaccine resulted in reduced rates of influenza in their community compared to a similar community in which children did not receive the vaccine, suggesting that vaccinating children may help prevent transmission of the virus and offer protection for unimmunized community residents, according to a study in the March 10 issue of
JAMA.
Influenza is a major cause of illness and death, resulting in an estimated 200,000 hospitalizations and 36,000 deaths annually in the United States alone. "Current vaccine policy focuses on immunizing those at high risk of complications of influenza. As a component of a broader policy to prevent the spread of influenza and reduce its complications, using immunization to interrupt community-wide transmission of influenza may be effective for protecting the entire population, including those at high risk," the authors write. They add that children and adolescents appear to play an important role in the transmission of influenza, and that selective vaccination against influenza among this group may interrupt virus transmission and protect those not vaccinated.
Mark Loeb, M.D., M.Sc., of McMaster University, Hamilton, Ontario, Canada, and colleagues assessed whether vaccinating children and adolescents with inactivated influenza vaccine could prevent influenza in other community members. Because randomizing entire communities to test the indirect benefit of vaccinating children and adolescents against influenza is not feasible in most settings, the researchers conducted their study among Hutterite (of the Anabaptist faith) colonies, which are rural communities found mostly in western Canada. "These tightly knit communities resemble extended families but are composed of single families each residing in their own house, where children and adolescents between the ages of 3 years and 15 years attend school. Approximately 60 to 120 people reside on each colony," the authors write.