Immunogenicity and Safety of a Cell-derived Influenza Vaccine in Adults Aged >= 18 and <= 64, Plus Revaccination

Inclusion Criteria 1. Willing and able to give informed consent and able to adhere to all protocol required study procedures. 2. Men and women aged \>= 18 and \<= 64 years. 3. Being in good health as judged by medical history, physical examination and clinical judgment of the investigator. Exclusion Criteria 1. Known to be allergic to constituents of the vaccine. 2. A serious adverse reaction after a previous (influenza) vaccination. Presence of any significant condition that may prohibit inclusion as determined by the investigator. 3. Having received vaccination against influenza or lab confirmed influenza within the previous six months before study vaccination.