title: Swine flu could come back in more virulent form after summer, European experts say.
authors.forename: Rory
authors.initials: R
authors.lastname: Watson
mesh_terms: D005060:Europe; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity*; D007251:Influenza, Human / Q000453:epidemiology*; D014774:Virulence