Their principal conclusion was that an increased incidence of narcolepsy was seen following a wave of upper airway infections (such as H1N1 influenza). They found no correlation between vaccination and narcolepsy. According to the authors, "the new finding of an association with infection, and not vaccination, is important as it suggests that limiting vaccination because of a fear of narcolepsy could actually increase overall risk."[8] Since narcolepsy is now believed to be an autoimmune disease,[7] the authors suspect that these upper airway infections trigger an immune response which leads ultimately to narcolepsy in susceptible individuals.