Titers are presented as geometric mean titers (GMTs). The reference cut-off value was 1:10. Antibodies assessed were antibodies against the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N2), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Results for Day 21 for the subjects in the GSK2282512A Group are the results specific to this primary outcome measure.

The analysis was performed on the According-To-Protocol cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

Titers are presented as geometric mean titers (GMTs). The reference cut-off value was 1:10. Antibodies assessed were antibodies against the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N2), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 flu strains. Subjects were assessed according to 2 age categories, 18-64Y and ≥ 65Y.

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

Titers are presented as geometric mean titers (GMTs). The reference cut-off value was 1:10. Antibodies assessed were antibodies against the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N2), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 flu strains. Subjects were assessed according to 2 age categories, 18-60Y and ≥ 61Y.

The analysis was performed on the According-To-Protocol (ATP) cohort for persistence, which included all vaccinated subjects who had not received a vaccine forbidden in the protocol with available assay results for assessed antibodies in Day 180 blood samples.

Medically-attended adverse events (MAEs) were non-serious and serious events leading to an otherwise unscheduled visit to or from medical personnel for any reason, including emergency room visits. If a medically-attended adverse event was leading to hospitalization (or met any other serious adverse event [SAE] criterion), it was reported as SAE.

The analysis was performed on the Total Vaccinated cohort, on subjects with available results.

Medically-attended adverse events (MAEs) were non-serious and serious events leading to an otherwise unscheduled visit to or from medical personnel for any reason, including emergency room visits. If a medically-attended adverse event was leading to hospitalization (or met any other serious adverse event [SAE] criterion), it was reported as SAE. Related MAE = MAE assessed by the investigator to be causally related to vaccination. Relationship to vaccination was not computed for MAEs.

The analysis was performed on the Total Vaccinated cohort, on subjects with available results.

Potential immune-mediated diseases (pIMDs) are a subset of adverse events that include both clearly autoimmune diseases and also other inflammatory and/or neurologic disorders which may or may not have an autoimmune etiology. Related pIMD = pIMD assessed by the investigator to be causally related to vaccination.

The analysis was performed on the Total Vaccinated cohort, on subjects with available results.

Serious adverse events (SAEs) assessed include medical occurrences that result in death, are life threatening, require hospitalization or prolongation of hospitalization, result in disability/incapacity or are a congenital anomaly/birth defect in the offspring of a study subject.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects.

Titers are presented as geometric mean titers (GMTs). The reference cut-off value was 1:10. Antibodies assessed were antibodies against the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N2), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 flu strains. Subjects were assessed according to 2 age categories, 18-64Y and ≥ 65Y.

The analysis was performed on the According-To-Protocol cohort for persistence, which included all vaccinated subjects who had not received a vaccine forbidden in the protocol, and with available assay results at Day 180 for assessed antibodies.

A seroprotected subject was defined as a vaccinated subject with serum Hemagglutination Inhibition titer ≥ 1:40. The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

A seroprotected subject was defined as a vaccinated subject with serum Hemagglutination Inhibition titer ≥ 1:40. The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Subjects were assessed according to 2 age categories, 18-60Y and ≥ 61Y.

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

A seroprotected subject was defined as a vaccinated subject with serum Hemagglutination Inhibition titer ≥ 1:40. The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Subjects were assessed according to 2 age categories, 18-64Y and ≥ 65Y.

The analysis was performed on the According-To-Protocol cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

A seroconverted subject was defined as a vaccinated subject who had either a pre-vaccination titer < 1:10 and a post-vaccination titer ≥1:40, or a pre-vaccination titer ≥1:10 and at least a four-fold increase in post-vaccination titer. The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Subjects were assessed according to 2 age categories, 18-64Y and ≥ 65Y.

The analysis was performed on the According-To-Protocol cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

The seroconversion factor (SCF) was defined as the fold increase in serum Hemagglutination Inhibition (HI) geometric mean titers (GMTs) post vaccination compared to Day 0 (i.e. the geometric mean of the within-subject ratios of the Day 21 reciprocal HI titer to the Day 0 reciprocal HI titer). The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Subjects were assessed according to 2 age categories, 18-64Y and ≥ 65Y.

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

Titers are presented as geometric mean titers (GMTs). The reference cut-off value was 1:10. Antibodies assessed were antibodies against the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N2), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 flu strains. Subjects were assessed according to 2 age categories, 18-60Y and ≥ 61Y.

The analysis was performed on the According-To-Protocol cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

Titers are presented as geometric mean titers (GMTs). The reference cut-off value was 1:10. Antibodies assessed were antibodies against the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N2), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 flu strains.

The analysis was performed on the According-To-Protocol cohort for persistence, which included all vaccinated subjects who had not received a vaccine forbidden in the protocol, and with available assay results at Day 180 for assessed antibodies.

A seroconverted subject was defined as a vaccinated subject who had either a pre-vaccination titer < 1:10 and a post-vaccination titer ≥1:40, or a pre-vaccination titer ≥1:10 and at least a four-fold increase in post-vaccination titer. The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains.

The analysis was performed on the According-To-Protocol cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

A seroconverted subject was defined as a vaccinated subject who had either a pre-vaccination titer < 1:10 and a post-vaccination titer ≥1:40, or a pre-vaccination titer ≥1:10 and at least a four-fold increase in post-vaccination titer. The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Subjects were assessed according to 2 age categories, 18-60Y and ≥ 61Y.

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

The seroconversion factor (SCF) was defined as the fold increase in serum Hemagglutination Inhibition (HI) geometric mean titers (GMTs) post vaccination compared to Day 0 (i.e. the geometric mean of the within-subject ratios of the Day 21 reciprocal HI titer to the Day 0 reciprocal HI titer). The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains. Subjects were assessed according to 2 age categories, 18-60Y and ≥ 61Y.

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

The seroconversion factor (SCF) was defined as the fold increase in serum Hemagglutination Inhibition (HI) geometric mean titers (GMTs) post vaccination compared to Day 0 (i.e. the geometric mean of the within-subject ratios of the Day 21 reciprocal HI titer to the Day 0 reciprocal HI titer). The 4 assessed influenza strains were the FLU A/California/7/09 (H1N1), FLU A/Victoria/210/09 (H3N1), FLU B/Brisbane/60/08 (BRI) and FLU B/Florida/4/06 (FLO) flu strains.

The analysis was performed on the According-To-Protocol (ATP) cohort for immunogenicity, which included all vaccinated and eligible subjects for whom data concerning Immunogenicity outcomes variables were available and for whom assay results were available for antibodies against at least one study vaccine component after vaccination.

Assessed solicited local symptoms were pain, redness and swelling at the injection site. Grade 3 pain = significant pain at rest/pain that prevented normal everyday activity. Grade 3 redness/swelling = redness/swelling spreading beyond 100 millimeters (mm) of injection site.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects, on subjects for whom results were available.

Assessed solicited general symptoms were fatigue, gastrointestinal symptoms (Gastr. Symptoms), headache, muscle ache, shivering, temperature - oral temperature equal to or above (≥) 38.0 degrees Celsius (°C) - and joint pain at location other than the injection site (Joint Pain). Grade 3 temperature = temperature ≥ 39.0 °C. Grade 3 symptom = symptom that prevented normal everyday activity. Related symptom = symptom assessed by the investigator as causally related to study vaccination. Joint pain data were collected for subjects in Canada and Mexico only.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects, on subjects for whom results were available.

Unsolicited AE covers any AE reported in addition to those solicited during the clinical study and any solicited symptom with onset outside the specified period of follow-up for solicited symptoms. Any = any unsolicited AE regardless of intensity or relationship to vaccination. Grade 3 = unsolicited AE that prevented normal everyday activity Related: unsolicited AE assessed by the investigator as related to the vaccination.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects.

Solicited local symptoms were pain, redness and swelling at the injection site. Analyses of duration for solicited local symptoms were not performed.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects, on subjects for whom results were available.

Assessed solicited general symptoms were fatigue, gastrointestinal symptoms (Gastr.), headache, muscle ache, shivering, temperature (defined as oral temperature equal to or above 38.0 degrees Celsius) and joint pain at location other than the injection site (Joint Pain). Joint pain data were collected for subjects in Canada and Mexico only. Analyses of duration for solicited general symptoms were not performed.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects, on subjects for whom results were available.

Unsolicited AE covers any AE reported in addition to those solicited during the clinical study and any solicited symptom with onset outside the specified period of follow-up for solicited symptoms. Any: any unsolicited AE regardless of intensity or relationship to vaccination. Grade 3 = unsolicited AE that prevented normal everyday activity. Analyses of duration for unsolicited AEs were not performed.

The analysis was performed on the Total Vaccinated cohort, which included all vaccinated subjects.