The purpose of this study is to evaluate the antibody response to each of the three influenza vaccine strains included in the licensed seasonal flu vaccine, as measured by hemagglutination inhibition (HAI) at 21 days post immunization in non-elderly and elderly subjects in compliance with the requirements of the current European Union (EU) recommendations for the evaluation of the immunogenicity for a new formulation of a licensed flu vaccine (CPMP/BWP/214/96).

Inclusion Criteria:

• Males or non-pregnant females and aged ≥ 18 years;
• Willing and able to adhere to visit schedules and all study requirements;
• Subjects read and signed the study-specific informed consent.

Exclusion Criteria:

• Subject or his/her family is employed by the participated hospital;
• Subjects received 2010-2011 seasonal influenza vaccine within the previous 6 months;
• History of hypersensitivity to eggs or egg protein or similar pharmacological effects to study medication
• Personal or family history of Guillain-Barré Syndrome
• An acute febrile illness within 1 week prior to vaccination;
• Current upper respiratory illness, including the common cold or nasal congestion within 72 hours
• Subjects with influenza-like illness as defined by the presence of fever (temperature ≥ 38°C) and at least two of the following four symptoms: headache, muscle/joint aches and pains (e.g. myalgia/arthralgia), sore throat and cough
• Female subjects who are pregnant during the study
• Treatment with an investigational drug or device, or participation in a clinical study, within 3 months before consent
• Immunodeficiency, or under immunosuppressive treatment
• Receipt of any vaccine within 1 week prior to study vaccination or expected receipt between Visit 1 (study vaccination) and Visit 2 (final collection of blood samples);
• Receipt of any blood products, including immunoglobulin in the prior 3 months;
• Underlying condition in the investigators' opinion may interfere with evaluation of the vaccine