Safety and Immunogenicity of a Subunit Trivalent Influenza Vaccine, Northern Hemisphere Formulation 2013/2014, Including MF59C.1 Adjuvant, in Healthy Adults ≥65 Years of Age

Inclusion Criteria

• Male or female volunteers aged 65 years or older, mentally competent, who gave written informed consent prior to study entry;
• Were able to comply with all the study requirements; and
• Were in good health as determined by the outcome of medical history, physical examination, and clinical judgment of the investigator.

Exclusion Criteria

• Had behavioral or cognitive impairment or psychiatric disease that, in the opinion of the investigator, may have interfered with the subject's ability to participate in the study;
• Had a serious chronic or acute disease (in the judgment of the investigator) including, but not limited to:
• medically significant cancer (except for benign or localized skin cancer, cancer in remission for >= 10 years, or localized prostate cancer that has been clinically stable for > 2 years without treatment)
• medically significant advanced congestive heart failure (ie, New York Heart Association [NYHA] class III and IV)
• chronic obstructive pulmonary disease (ie, Global initiative for chronic Obstructive Lung Disease [GOLD] stage III and IV)
• autoimmune disease (including rheumatoid arthritis and excepting Hashimoto's thyroiditis that has been clinically stable for >= 5 years)
• diabetes mellitus type I
• poorly controlled diabetes mellitus type II
• advanced arteriosclerotic disease
• history of underlying medical condition such as major congenital abnormalities requiring surgery, chronic treatment, or associated with developmental delay (eg, Down's syndrome)
• acute or progressive hepatic disease
• acute or progressive renal disease
• severe neurological (especially Guillain-Barré syndrome) or psychiatric disorder
• severe asthma
• Had a history of any anaphylactic reaction and/or serious allergic reaction to any component of the study vaccine.
• Had a known or suspected (or have a high risk of developing) impairment/alteration of immune function (excluding that normally associated with advanced age) resulting, for example, from:
• receipt of immunosuppressive therapy (any parenteral or oral corticosteroid or cancer chemotherapy/radiotherapy) within the past 60 days and for the full length of the study,
• receipt of immunostimulants within the past 6 months,
• receipt of parenteral immunoglobulin preparation, blood products, and/or plasma derivates within the past 3 months and for the full length of the study, or
• suspected or known human immunodeficiency virus (HIV) infection or HIV related disease.
• Had known or suspected drug or alcohol abuse within the past 2 years;
• Had bleeding diathesis or conditions associated with prolonged bleeding time that, in the investigator's opinion, would have interfered with the safety of the subject;
• Was not able to comprehend and to follow all required study procedures for the whole period of the study;
• Had a history or any illness that, in the opinion of the investigator, would have posed additional risk to the subjects because of participation in the study;
• Had the following within the past 6 months:
• any laboratory confirmed seasonal or pandemic influenza disease,
• received any seasonal or pandemic influenza vaccine.
• Had received any other vaccine within 4 weeks prior to enrollment in this study or who were planning to receive any vaccine during the study;
• Had acute or chronic infections requiring antiviral therapy within the last 7 days;
• Had experienced fever (ie, body temperature [preferably oral] >= 38.0°C) within the last 3 days of intended study vaccination;
• Had been participating in any clinical trial with another investigational product 4 weeks prior to first study visit or intended to participate in another clinical study at any time during the conduct of this study;
• Was part of study personnel or had close family members conducting this study;
• Had a body mass index (BMI) >35 kg/m2 (BMI is calculated by dividing the subject's weight in kilograms by the subject's height in meters multiplied by the subject'