2010/2011 Trivalent Influenza Vaccination

Inclusion Criteria: * All participants qualified for the HA/ CHP Mass Vaccination Program for TIV 2010/2011 seasonal influenza as stated above: including all elderly at the age of 65 or above and all adult patients at the age of 21 or above that are either healthcare workers or that have a chronic illness including hypertension, diabetes mellitus, ischemic heart disease, cerebrovascular disease, thyroid disease and chronic renal failure. * All patients give written informed consent. * Subjects must be available to complete the study and comply with study procedures. Exclusion Criteria: * Clinically significant immune-related diseases, significant recent co-morbidities and pregnant volunteers. * History or any illness that might interfere with the results of the study or pose additional risk to the subjects due to participation in the study * Have a known allergy to eggs or other components of the Study Vaccines (including gelatin, formaldehyde, octoxinol, thimerosal, and chicken protein), or history of any anaphylaxis, serious vaccine reactions, to any excipients. * Have immunosuppression as a result of an underlying illness or treatment, or use of anticancer chemotherapy or radiation therapy (cytotoxic) within the preceding 36 months. * Have an active neoplastic disease or a history of any hematologic malignancy. * Have known active human immunodeficiency virus (HIV), Hepatitis B, or Hepatitis C infection or autoimmune hepatitis and cirrhosis. * History of progressive or severe neurological disorders or Guillain-Barré Syndrome.