This maximum alert level issued by the WHO triggered a series of measures in Europe, including the activation of immunisation campaigns in several Member States which not only were very costly but were also overestimated in relation to the known severity of the virus, which, as the WHO stated at that time in May 2009, was moderate.
See WHO välja kuulutatud maksimaalne häiretase tõi Euroopas kaasa arvukalt meetmeid, muu hulgas ka vaktsineerimiskampaaniate käivitamise mitmes liikmesriigis, mis ei olnud mitte ainult väga kulukad, vaid ka viiruse teadaoleva raskusastme osas ülehinnatud, kuna tollel ajal, 2009. aasta mais, oli ohutase WHO hinnangul mõõdukas.