Epidemiological studies have demonstrated an association between H1N1 influenza infection and vaccinations.This article reviews the various studies, and suggests the biological mechanisms explaining why and how H1N1 influenza infection or Aids To Daily Living vaccine stimulates the autoimmune response, thereby resulting in narcolepsy.Among the vaccines, the effect of Pandemrix was scrutinized more than other vaccines, due to its higher association with an increase of narcolepsy onset.The consequences of using other vaccines Sleeper Sofa which contain same or different adjuvants as Pandemrix, were also analyzed.