​An important conclusion from this process is that the current situation, with B viruses dominating (80%), is likely to continue through the season.

This initiative was taken following the indication of a potential association between the 2009 pandemic influenza A(H1N1) monvalent vaccine and the occurrence of narcolepsy following reports, especially in children from Finland and Sweden.

This recommendation for the Northern Hemisphere is the same as for the season 2010-2011 and for the Southern Hemisphere season.

In February 2011, ECDC published a report concerning a rise in narcolepsy in children and adolescents in some northern countries.

​The European Parliament adopted a resolution on the evaluation of the pandemic in its sitting on the 8th March 2011.

A four-fold increased incidence of narcolepsy in vaccinated children/adolescents compared to unvaccinated children was observed in this register-based cohort study.

In late March, 2011 ECDC reported that the Swedish Medical Product Agency published preliminary results from an on-going cohort study involving 5.3 million people, where 67% of children and adolescents and 51.0% of adults were vaccinated with Pandemrix.

The European Medicines Agency (EMA) was key in the Europe during the 2009 pandemic concerning the authorisation and the benefit – risk assessment of the novel pandemic vaccines.