Study Comparing Immune Response to, and Safety of, Fluviral and Fluzone Influenza Vaccines in Persons 50 y.o. and Over

Inclusion Criteria: * Stable health status * Access to a consistent means of telephone contact. * Comprehension of study requirements, availability for study duration * Availability and ability to attend scheduled visits * Females post menopausal, sterile or using accepted contraceptive measures * Competence to provide informed consent Exclusion Criteria: * Presence of significant acute or chronic medical or neuropsych. illness * New medical or surgical treatment w/i 1 month * Change in medication dose due to uncontrolled symptoms w/i 1 month * Hospitalization w/i 1 month * Any unusual risk (for age group) of serious adverse events w/i 1 month * Any neuropsychiatric condition altering competence for consent * Any neuropsychiatric condition preventing accurate safety reports * Febrile illness on day of treatment * Employment in professions at high risk of influenza transmission * Residence in a long-term-care facility or with an immunocompromised person * Systolic BP over 150, diastolic over 90, resting pulse under 50 or over 100 * Cancer w/i 3 years * Immunosuppressive of immunodeficient conditions * Treatment with systemic glucocorticoids \> replacement * Treatment with cytotoxic or immunosuppressant drugs * Treatment with immune globulins * Clotting disorders that increase the risks of intramuscular injections * History of demyelinating disease or GBS * Pregnancy or nursing * Absence of contraceptive practices in women with childbearing potential * Planned administration of non-influenza vaccines within 30 days * Receipt of any investigational drug within 30 days * Receipt of immune globulin treatment within 3 months * Known or suspected allergy to egg proteins, gelatin, or thimerosal * History of severe adverse reactions toflu vaccines * Prior receipt of 2005-6 influenza vaccine