Adolescent|Adult|Age Distribution|Aged|Aged, 80 and over|Child|Child, Preschool|Computer Simulation|Data Interpretation, Statistical|Female|Finland|Humans|Incidence|Infant|Infant, Newborn|Influenza Vaccines|Influenza, Human|Male|Mass Vaccination|Middle Aged|Models, Statistical|Pandemics|Reproducibility of Results|Risk Assessment|Seasons|Sensitivity and Specificity|Sex Distribution|Young Adult