Figure. Daily incidence of acute respiratory illness (ARI) cases at base infirmary, by case definition. Shaded segment of bar indicates ARI cases that met the definition of influenzalike illness (ILI) (temperature >37.8°C). Nonshaded segment indicates ARI cases that did not meet the ILI criterion (non-ILI). Arrows: a) vaccination campaign initiation, b) vaccination campaign termination, c) day 14 after campaign initiation.