The invention relates to a method for producing the flu virus, that comprises:a) administering a flu vaccine tohens； b) collecting the eggs of the vaccinated hens； c) triggering theembryogenesis process； d) infecting the embryonated eggs byinoculating a flu virus in the allantoic cavity； e) incubating the infectedembryonated eggs in temperature and humidity conditionsallowing the virus replication； and f) collecting the allantoic liquidcontaining the virus.
