[Influenza]

Yearly epidemics and occasional pandemics with Influenza have been observed for several hundred years. During the last pandemic the reported deaths due to confirmed influenza was lower than expected. New epidemiologic analyses demonstrate that the severity has probably been underestimated. In addition, cohort data from severely ill patients support the use of neuraminidase inhibitors in complicated influenza infections. Due to the increasing divergence of the two circulation Influenza B strains, WHO has recommended a quadrivalent vaccine. Several quadrivalent vaccines have been successfully developed. The association of adjuvanted 2009 pandemic vaccine and narcolepsy is still debated, new data from several countries contribute to this discussion. Avian viruses have fuelled all pandemics since 1918. Surveillance of avian influenza viruses is thus regarded essential for pandemic preparedness. In 2013 a new avian influenza virus, H7N9 has cause human infections and deaths. This new strain has low pathogenicity in birds and thus surveillance is especially challenging.