This report summarises the results from two epidemiological studies to investigate a possible association between an unexpected increase in narcolepsy cases following the use of the influenza A(H1N1)pdm09 vaccines. The studies were conducted by the Vaccine Adverse Event Surveillance and Communication (VAESCO) Consortium under the auspices of ECDC and undertaken in Denmark, Finland, France, Italy, the Netherlands, Norway, Sweden and the United Kingdom. This Technical Report In Brief accompanies the full Report ‘Narcolepsy in association with pandemic influenza vaccination- A multi-country European epidemiological investigation’.

This report summarises the results from two epidemiological studies conducted by the Vaccine Adverse Event Surveillance and Communication (VAESCO) Consortium undertaken in eight European Union (EU)/European Economic Area (EEA) countries in order to investigate a possible association between an unexpected increase in narcolepsy cases following the use of influenza A(H1N1)pdm09 vaccines. Narcolepsy is an underdiagnosed disease of widely unknown etiology.

This extended report aims to provide a broad overview of the epidemiology and virology of the 2009 pandemic in the European Union and European Economic Area countries. The main trends and information are derived from the analysis and interpretation of the epidemiological and virological data and other analyses provided to the European Centre for Disease Prevention and Control’s European Surveillance system through the European Influenza Surveillance Network.

This guide is intended for use by those involved in pandemic preparedness planning, generic preparedness and implementation of IHR core capacities in European countries. The document describes good practice for pandemic preparedness planning based on lessons learned from the 2009 pandemic.