Influenza is a vaccine-preventable disease. However, influenza virus spreads among children in schools and daycare centers, then to families and communities, causing uncontrolled epidemics every winter. The United States Food and Drug Administration evaluated and approved an investigational live-attenuated, cold-adapted, trivalent influenza vaccine for licensure, for prevention of influenza in healthy children and healthy adults, 5 through 49 years of age. Could protection of healthy schoolchildren against influenza limit its spread and benefit society?