[Flu vaccine in children: state of the art]

Influenza is an acute respiratory illness that year to year causes considerable morbidity and mortality. . All children, healthy or at high risk, are susceptible to this infection. Influenza vaccine seems to be effective in preventing influenza-like illness, laboratory-confirmed infection, and hospitalizations and deaths, demonstrating cost-effectiveness. Inactivated and live-attenuated vaccines have a similar efficacy profile. . Due to high influenza associated hospitalization rates in children, some countries have recommended incorporating influenza vaccination into the universal immunization program for healthy infants between 6-24 months of age. Considering that this public-health policy has been incorporated in Chile, local studies assessing its impact are needed.