Study on the Incidence of Influenza and Its Complications, in Subjects Aged 50 Years and Over Vaccinated With Fluarix™

Primary outcomes

1. Number of Subjects With at Least One Influenza-like-infection (ILI) Episode

   Time frame: From Month 0 to Month 6

   Analysis included all non-confirmed or lab confirmed ILI episodes (at least 1 episode, 1 episode, 2 episodes or more than (>) 2 episodes) reported.

2. Number of Subjects With Laboratory-confirmed Influenza Infection Type A and/or Type B

   Time frame: From Month 0 to Month 6

   Lab confirmed ILI episodes were assessed by means of viral culture (VC) infection (nasal and throat swabs) determination and/or using the Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) assay.

3. Number of Subjects With Hospitalization, Emergency Room Visits, or Unscheduled Medical Office Visits Due to ILI

   Time frame: From Month 0 to Month 6

   ILI which led to subject hospitalization, emergency room visits and unplanned medical office visits were recorded by number (at least 1, 1, or above 1), as part of the ILI surveillance.

4. Number of Subjects With Hospitalizations, Emergency Room Visits or Unscheduled Medical Office Visits, Due to Laboratory Confirmed Influenza

   Time frame: From Month 0 to Month 6

   Laboratory confirmed (LC) ILI which led to subject hospitalization, emergency room visits and unplanned medical office visits were recorded by number (at least 1, 1, or above 1), as part of the ILI surveillance.

5. Number of Subjects With Hospitalization or Emergency Room Visit for Any Cause

   Time frame: From Month 0 to Month 6

   As part of ILI surveillance any reasons, or other reasons than those mentioned which led to subject hospitalization, emergency room visits and unplanned medical office visits were recorded by number (at least 1, 1, or above 1).

6. Number of Subjects With Emergency Room Visits, or Unscheduled Medical Office Visits Due to Influenza-related Complications

   Time frame: From Month 0 to Month 6

   ILI complications which led to subject hospitalization, emergency room visits and unplanned medical office visits were recorded by number (at least 1, 1, or above 1) as part of the ILI surveillance, which included: pneumonia, ischemic heart disease, congestive failure, acute cerebrovascular disease chronic obstructive pulmonary disease (COPD) exacerbation.

7. Number of Subjects With Influenza-related Complications

   Time frame: From Month 0 to Month 6

   ILI complications refer to episodes of pneumonia, ischemic heart disease [HD] (unstable angina or myocardial infarction), congestive heart failure [HF], acute cerebrovascular disease [ACD] (stroke or transient ischemic attack [IA]), COPD exacerbation and all illnesses (pooled episode of each illness). ILI complications were recorded by number of episodes (at least 1 episode, 1 episode and above 1 episode).

8. Number of Subjects With Fatal Outcomes Due to Laboratory Confirmed Influenza Infection

   Time frame: From Month 0 to Month 6

   Death due to lab confirmed influenza infection was recorded during the influeza period only.

9. Number of Subjects With Fatal Outcomes

   Time frame: From Month 0 to Month 6

   Number of deaths caused by laboratory non-confirmed ILI or other reasons were recorded during the influenza

10. Number of Subjects With Laboratory-confirmed Respiratory Syncytial Virus Infection (RSV)

    Time frame: From Month 0 to Month 6

    RSV infection was determined by the RT-PCR assay.

11. Number of Subjects With Serious Adverse Events (SAEs)

    Time frame: From Month 0 to Month 6

    SAEs assessed include medical occurrences that result in death, are life threatening, require hospitalization or prolongation of hospitalization or result in disability/incapacity or are a congenital anomaly/birth defect in the offspring of a study subject. Any was defined as occurrence of any symptom regardless of intensity grade or relation to vaccination and related was an event assessed by the investigator as causally related to the study vaccination.

12. Number of Seroconverted Subjects for Each Influenza Strain

    Time frame: At Day 21

    A seroconverted subject was defined as a subject having either a pre-vaccination hemagglutinin inhibition (HI) titer lower than (<) 1:10 and a post-vaccination titer greater than or equal to (≥) 1:40, or a pre-vaccination titer ≥1:10 and a minimum four-fold increase in the post-vaccination titer. Assessed influenza strains were A/New Caledonia, A/Wisconsin and B/Malaysia.

13. Seroconversion Factor for Hemagglutination Inhibition (HI) Antibodies Against 3 Strains of Influenza Disease

    Time frame: At Day 21

    The seroconversion factor (SCF) was defined as the fold increase in serum HI geometric mean titer (GMT) post vaccination on Day 21 compared to Day 0. The 3 influenza strains assessed were A/New Caledonia, A/Wisconsin and B/Malaysia.

14. Number of Seroprotected Subjects Against the 3 Influenza Strains

    Time frame: At Day 0 (PRE)

    A seroprotected subject was defined as a vaccinated subject with a serum HI titer ≥1:40.

15. Number of Seroprotected Subjects Against the 3 Influenza Strains

    Time frame: At Day 21

    A seroprotected subject was defined as a vaccinated subject with a serum HI titer ≥1:40.

16. Number of Seropositive Subjects for Each Influenza Strain

    Time frame: At Day 0 (PRE)

    A seropositive subject was defined as a vaccinated subject with antibody titer ≥1:10.

17. Number of Seropositive Subjects for Each Influenza Strain

    Time frame: At Day 21

    A seropositive subject was defined as a vaccinated subject with an antibody titer ≥1:10.

18. Serum HI Antibody Titers for Each Influenza Strain

    Time frame: At Day 0 (PRE)

    Serum HI antibody titers were expressed as Geometric Mean Titers (GMTs).

19. Serum HI Antibody Titers for Each Influenza Strain

    Time frame: At Day 21

    Serum HI antibody titers were expressed as Geometric Mean Titers (GMTs).