Immunogenicity, Safety, and Tolerability of an MF59-Adjuvanted Versus Non-Adjuvanted Influenza Vaccines in Patients With Chronic Pulmonary Disease, Chronic Heart Disease, or Diabetes Mellitus

Inclusion Criteria: For Subjects with Chronic Diseases: * Subjects between 18 and 70 years of age (inclusive) * Any sex or ethnicity * Outpatient or hospitalized subjects * Confirmed diagnosis of chronic pulmonary and/or cardiac, and/or diabetes mellitus based on the investigator's assessment (subjects may present one or more of such conditions) * Childbearing potential women must be willing to use an acceptable contraceptive method. Acceptable contraceptive methods are defined as one or more of the following: 1. Hormone contraceptive (such as oral, injectable, transdermal patch, subcutaneous implant, cervical ring) 2. Barrier (condom with spermicide or diaphragm with spermicide) at each intercourse and during the whole intercourse 3. Intra-uterine device (IUD) 4. Monogamous relation with vasectomized partner (must have been vasectomized at least six months before the volunteer entered the study) * Subjects capable of following all the study procedures and available for all visits scheduled to the investigation site * Subjects capable of understanding the nature and risk of the study proposed and sign the consent form * The study subjects may have other underlying chronic diseases that do not involve immunosuppression (e.g. osteoarticular diseases, stable, non-progressive, non-severe neurologic disorders without cognitive impairment, ophthalmologic diseases, hypothyroidism, etc.), but their symptoms/signs must be under control through medical follow-ups and drug therapy For Healthy Subjects: * Subjects between 18 and 70 years of age (inclusive) * Any sex and ethnicity * Subjects with good health as determined by medical history, physical evaluation, and investigator's clinical opinion * Childbearing potential women must be willing to use an acceptable contraceptive method. Acceptable contraceptive methods are defined as one or more of the following: 1. Hormone contraceptive (such as oral, injectable, transdermal patch, subcutaneous implant, cervical ring) 2. Barrier (condom with spermicide or diaphragm with spermicide) at each intercourse and during the whole sexual intercourse 3. Intra-uterine device (IUD) 4. Monogamous relation with vasectomized partner (must have been vasectomized for at least six months before the volunteer entered the study) * Subjects capable of respecting all the study procedures and available for all the visits scheduled at the investigation site * Subjects capable of understanding the nature and risk of the study proposed and sign the consent form Exclusion Criteria: For Subjects with Chronic Diseases * Previous laboratory confirmed diagnosis of an infection by the novel H1N1 virus * Administration of other vaccine against the novel H1N1 virus within 3 months prior to inclusion in the study * Any recent vaccine given within the last 21 days (inclusive) * History of allergic reaction to an influenza vaccine in the past, or a current or previous occurrence of allergy to egg or egg protein, kanamycin, and neomycin sulfate * Acute febrile disease (vaccination may be delayed up to 3 days after the resolution of the symptoms) * History of cancer, except for skin cancer, including Kaposi's Sarcoma, basal cell carcinoma, and non-invasive malignancy related to HPV * History of chronic hepatic or renal disease * History of cognitive disorders * History of progressive or severe neurological disorders, including Guillain-Barré Syndrome * Pregnancy or breast-feeding * Use of immunomodulatory therapy, including cyclosporin,interleukins, and interferons, within 3 months prior to inclusion in the study * Receipt of parenteral immunoglobulin, hemotherapy, and/or plasma derivatives within 3 months prior to inclusion in the study * Life expectancy of at least 12 months * Receipt of any investigational product within 12 months prior to inclusion in the study For Healthy Subjects: * Previous laboratory confirmed diagnosis of an infection by the new virus H1N1 * Receipt of another vaccine against the new virus H1N1 within 3 months prior to inclusion in the study * Any recent vaccine given within the last 21 days (inclusive) * History of allergic reaction to influenza vaccine in the past, or a current or previous allergy to egg or egg protein, kanamycin, and neomycin sulfate * Acute febrile disease (the vaccination may be delayed up to 3 days after symptoms resolution) * Pregnancy or breast-feeding * Receipt of parenteral immunoglobulin, hemotherapy, and/or plasma derivatives within 3 months prior to inclusion in the study * Receipt of any investigational product within 12 months prior to inclusion in the study