This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study to Evaluate the Safety and Immunogenicity of GSK Biologicals' Seasonal Influenza Vaccine in Adults (NCT01196975), a randomized phase 3 study. The primary outcome is Titers for Serum Hemagglutination Inhibition (HI) Antibodies Against 4 Strains of Influenza Disease.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01196975 |
| Phase | Phase 3 |
| Condition | Influenza |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 1707 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
The trial enrolled adults aged 18 years and older and studied influenza vaccination. The primary immunogenicity analysis used the According-To-Protocol cohort for immunogenicity: vaccinated and eligible participants with available immunogenicity data and assay results for antibodies against at least one study vaccine. The total trial enrollment was 1707, but the number included in the primary analysis is not reported in the registry record.
Intervention
The intervention was GSK Biologicals’ quadrivalent seasonal influenza vaccine, GSK2282512A. Participants assigned to this vaccine received one intramuscular dose in the deltoid region of the non-dominant arm. The trial included three GSK2282512A groups, each receiving a different vaccine lot.
Comparator
The comparator groups received one intramuscular dose of FluLaval-VB, containing the Victoria B strain, or FluLaval-YB, containing the Yamagata B strain. Both were administered in the deltoid region of the non-dominant arm. The registry also describes the trial’s objective of evaluating consistency across three GSK2282512A lots.
Primary question
The primary outcome measured serum hemagglutination inhibition antibody titers against four influenza strains, reported as geometric mean titers at Day 0 and Day 21 after vaccination. The primary outcome description specifies Day 21 results for the GSK2282512A group. The registry record does not provide a single contrast or numerical primary outcome result from which to state how the groups compared.
3. Trial Design
This was a phase 3, randomized, double-masked, parallel-group trial. The registry lists 1707 participants as enrolled and identifies the study status as completed. The study began on 2010-10-01, and primary completion was recorded as 2011-01-25. These dates describe the trial record and do not, by themselves, establish the timing or completeness of any particular outcome assessment.
Participants received one dose on Day 0. Three groups received GSK2282512A from Lot 1, Lot 2, or Lot 3. Two additional groups received FluLaval-VB, containing the Victoria B strain, or FluLaval-YB, containing the Yamagata B strain. Each vaccine was administered intramuscularly in the deltoid region of the non-dominant arm. The registry describes an objective of evaluating lot-to-lot consistency for three vaccine lots as well as immunogenicity and safety.
Random allocation is intended, in general, to balance measured and unmeasured baseline characteristics across assigned groups on average. Double masking is intended, in general, to reduce the influence of treatment knowledge on participant reports and study assessments. The registry identifies these design features, but details of the allocation procedure and masking implementation are not reported in the registry record.
The primary outcome was serum hemagglutination inhibition antibody titer against four influenza strains, expressed as a geometric mean titer with a 95% confidence interval. Measurements were specified at Day 0 and Day 21 after vaccination. The primary outcome description identifies Day 21 results for the GSK2282512A group. Several outcome categories and time points are involved, and the registry record does not define one overall comparison that reduces them to a single estimate.
The registry lists 25 outcome measures. Secondary outcomes include antibody titers by age strata, seroprotection, and several safety outcomes, including medically attended adverse events, potential immune-mediated diseases, and serious adverse events. The analysis population, missing-data handling, and detailed statistical analysis plan are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: For some outcome measures, the subjects receiving the GSK2282512A vaccine, from Lot 1, 2 or 3, were pooled into one larger pooled group, the GSK2282512A Group, and/or groups were stratified into the 4 age categories: 18 to 60 years (18-60Y), 61 years and older (≥61Y), 18 to 64 years (18-64Y), and 65 years and older (≥ 65Y).
Overall Study
| Stage | GSK2282512A 1 Group | GSK2282512A 2 Group | GSK2282512A 3 Group | Victoria Strain FluLaval Group | Yamagata Strain FluLaval Group |
|---|---|---|---|---|---|
| STARTED | 423 | 424 | 425 | 213 | 218 |
| COMPLETED | 408 | 415 | 420 | 207 | 205 |
| NOT COMPLETED | 15 | 9 | 5 | 6 | 13 |
Reasons for not completing this period:
| Reason | GSK2282512A 1 Group | GSK2282512A 2 Group | GSK2282512A 3 Group | Victoria Strain FluLaval Group | Yamagata Strain FluLaval Group |
|---|---|---|---|---|---|
| Adverse Event | 2 | 2 | 0 | 0 | 2 |
| Withdrawal by Subject | 2 | 1 | 0 | 1 | 0 |
| Lost to Follow-up | 11 | 6 | 5 | 5 | 11 |
Analysis population for the primary outcome, as defined in the registry: 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.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | GSK2282512A 1 Group | GSK2282512A 2 Group | GSK2282512A 3 Group | Victoria Strain FluLaval Group | Yamagata Strain FluLaval Group | Total |
|---|---|---|---|---|---|---|---|
| Participants analysed | 423 | 424 | 425 | 213 | 218 | 1703 | |
| Age, Continuous | Years | 49.9 (SD 19.49) | 50.4 (SD 19.07) | 49.8 (SD 20.10) | 50.8 (SD 18.58) | 49.6 (SD 19.34) | 50.1 (SD 19.32) |
| Sex: Female, Male: Female | Participants | 251 | 264 | 266 | 125 | 138 | 1044 |
| Sex: Female, Male: Male | Participants | 172 | 160 | 159 | 88 | 80 | 659 |
6. Primary Endpoint
The registry lists the primary outcome as Titers for Serum Hemagglutination Inhibition (HI) Antibodies Against 4 Strains of Influenza Disease, measured over At Day 0 (D0) and at Day 21 (D21) post vaccination..
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Titer |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the serum hemagglutination inhibition antibody titer against four influenza strains: 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). The registry describes titers as geometric mean titers and gives a reference cutoff value of 1:10. Measurements were planned at Day 0 and Day 21 after vaccination; the endpoint description identifies the Day 21 results for participants in the GSK2282512A group as the primary outcome results.
In general, the hemagglutination inhibition assay measures whether serum antibodies inhibit a virus’s ability to agglutinate red blood cells. A titer is a measure of antibody activity expressed through the assay’s dilution procedure. Geometric means are commonly used for titers because such measurements are often multiplicative and can be skewed on their original scale. A confidence interval communicates uncertainty around an estimated geometric mean; it is not a range containing every participant’s titer.
The endpoint is an immunogenicity measure, not a direct measure of clinical illness or protection in an individual. The registry also lists seroprotection as a secondary outcome, but the numerical results and a definition for that outcome are not reported in the registry record. Numerical primary endpoint estimates and their confidence intervals are likewise not reported in the registry record available for this analysis.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a randomized comparison of GSK2282512A and two FluLaval vaccines in adults, with antibody titers assessed at Day 0 and Day 21. It also identifies three GSK2282512A vaccine-lot groups. These details establish the study question and measurement schedule, but they do not establish the direction or size of any antibody response. The primary outcome values and confidence intervals are not reported in the registry record.
The primary endpoint is presented as geometric mean titers for four specified influenza strains. Because there are multiple strains and time points, a single overall effect cannot be inferred without a defined summary or contrast. The registry record does not specify one comparison that combines these outcomes, and its outcome description emphasizes Day 21 results for the GSK2282512A group. It would therefore be inappropriate to summarize the record as showing that one vaccine had higher or lower titers than another.
In general, a confidence interval indicates the precision of an estimate under the assumptions of the analysis. A narrow interval indicates greater precision than a wider interval for the same kind of estimate, but neither width nor statistical significance alone establishes clinical importance. No primary endpoint intervals are reported in the registry record, so precision cannot be assessed from the information available.
The registry lists safety counts by group for serious adverse events and other adverse events. For serious adverse events, the recorded affected and at-risk counts are 15 and 423 for GSK2282512A Lot 1; 13 and 424 for Lot 2; 7 and 425 for Lot 3; 3 and 213 for FluLaval-VB; and 7 and 218 for FluLaval-YB. For other adverse events, the corresponding recorded counts are 294 and 417; 286 and 421; 284 and 422; 127 and 208; and 113 and 216. The registry record does not provide enough information in the registry record to interpret these counts as comparable risks over a specified period, or to assess the statistical uncertainty around group differences.
Some serious adverse-event terms are listed with a frequency of 0.5% each: angina unstable, gastrointestinal mucosal disorder, upper gastrointestinal haemorrhage, fracture displacement, hip fracture, and hypoaesthesia. The registry record does not provide event-level detail or a basis for drawing causal conclusions from those terms. Death figures are not reported in the registry record.
The outcome listing is broad, but the record does not supply numerical immunogenicity results, detailed analysis methods, or a single prespecified contrast for interpretation. The trial’s completed status is not itself evidence of a particular result. Conclusions about comparative immunogenicity or safety should be limited to results and analyses actually reported in the registry record.
9. Statistical Methods Explained
Statistical interpretation depends on the outcome definition, the comparison being estimated, the analysis population, and the uncertainty around the estimate. The registry record identifies the primary measure and design features, but does not report numerical primary outcome results or a detailed statistical analysis plan.
What does a geometric mean titer represent?
In general, a geometric mean is calculated on a logarithmic scale and then expressed on the original scale. This approach is often used for antibody titers because titers are measured through serial dilutions and can vary multiplicatively. A geometric mean describes a central level on that scale; it is not the arithmetic average of the raw titers. The registry identifies geometric mean titers for antibodies against four strains, with a reference cutoff value of 1:10.
A geometric mean does not describe the full distribution of individual responses. Two groups could have similar geometric means while differing in the spread or shape of their distributions. The registry lists seroprotection as a secondary outcome, which is a different way of summarizing responses. Numerical values for either outcome are not reported in the registry record.
How should the confidence interval be read?
In general, a confidence interval represents uncertainty in an estimate under the statistical model and sampling process used. It is not a guarantee that the true value lies within the interval, and it does not describe the range of participant-level measurements. The primary outcome specifies 95% confidence intervals, but no numerical intervals are reported in the registry record. Without estimates and intervals, the precision of the antibody-titer results cannot be evaluated.
When comparing groups, an interval for each group separately is not always equivalent to an interval for the difference or ratio between groups. The relevant uncertainty measure depends on the estimand: the precise quantity the analysis is intended to estimate. The registry record does not identify a single primary contrast across the multiple strains, time points, and vaccine groups, so a specific comparative estimand should not be assumed.
Why do the multiple strains and time points matter?
The endpoint includes measurements against four named strains at Day 0 and Day 21. In general, testing multiple outcomes creates multiplicity: the more separate comparisons considered, the greater the chance of finding an apparently unusual result by chance if each is assessed independently. Statistical procedures can address multiplicity, but the choice depends on the analysis plan and inferential goal. A multiplicity adjustment or hierarchy is not reported in the registry record. It is also not reported whether Day 0 values were used as a baseline adjustment in any analysis.
Because the primary outcome description specifies Day 21 results for the GSK2282512A group, it does not by itself establish a between-group effect. A comparison would require a defined comparator, a defined outcome contrast, and a statistical method. Those details and the resulting estimates are not reported in the registry record.
What does randomization contribute?
In general, random allocation supports causal comparison by reducing systematic differences between assigned groups at baseline, on average. It does not guarantee that every measured characteristic is identical, nor does it prevent bias from missing outcomes, protocol deviations, or differences in follow-up. The registry identifies randomization and a parallel-group design, but the allocation sequence, concealment procedures, and balance of baseline characteristics are not reported in the registry record.
Double masking can reduce some influences of treatment knowledge on participant reporting and outcome assessment. It does not eliminate every possible source of bias. The registry identifies the study as double-masked, but who was masked and how masking was maintained are not reported in the registry record.
What can the safety counts tell us?
The registry lists numbers of participants affected and at risk for serious and other adverse events in each group. Counts are useful for describing what was recorded, but a count alone does not characterize the seriousness, timing, duration, recurrence, or causal relationship of an event. General statistical interpretation of a group comparison would also require a defined follow-up period and information about how participants with incomplete safety follow-up were handled. Those details are not reported in the registry record.
In general, over-dispersion occurs when observed variability exceeds what a chosen statistical model assumes. It can make uncertainty estimates too small if ignored. Whether over-dispersion is relevant depends on the outcome and model; the registry record does not report a model for the safety analyses, so no claim about its presence or handling can be made.
How should planning estimates be understood?
In general, sample-size calculations are planning exercises based on assumptions about the effect to detect, variability, significance level, allocation, and statistical method. They are not evidence that an effect was observed, and they are not observed power. The planning illustration associated with this trial is described as using the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. The record does not report the trial’s own sample-size justification or the assumed design effect. Any planning illustration should therefore be read as hypothetical, not as proof that the trial was adequately powered for every endpoint or comparison.
In particular, the record does not report the sample-size calculation used to plan the randomized groups, the assumed response variability, or whether adjustments were made for multiple strains, lot comparisons, or attrition. Those design details are not reported in the registry record. No conclusion about observed power or the adequacy of the trial size follows from enrollment alone.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint spans antibody titers against four influenza strains and measurements at Day 0 and Day 21. Secondary outcomes add age-stratified titers, seroprotection, and multiple safety categories. In general, evaluating many outcomes or contrasts raises multiplicity concerns because chance findings become more likely when many separate tests are considered. Possible approaches include prespecifying a primary contrast, using a hierarchy of tests, or adjusting inference across a family of comparisons. Which approach was used is not reported in the registry record.
The registry identifies the According-To-Protocol cohort for immunogenicity as the primary analysis population. It describes that cohort as vaccinated and eligible participants with immunogenicity data and assay results for antibodies against at least one study vaccine. The number analyzed is not reported in the registry record. The record also does not report the number excluded from this population, the reasons for exclusion, or whether additional analysis populations were used.
Missing-data handling is important because participants without available assays or follow-up may differ from those with observed measurements. In general, methods that rely on complete observations require assumptions about how missingness relates to outcomes; other approaches may use explicit models or sensitivity analyses. The method used, the extent of missing primary outcome data, and any sensitivity analyses are not reported in the registry record.
The registry’s outcome listing and cohort description do not establish whether baseline titers were adjusted for, how protocol deviations were handled, or whether analyses followed assigned groups. These details are not reported in the registry record. Consequently, the listed analysis population can be described, but the full analysis strategy and its robustness to missingness or multiplicity cannot be evaluated.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| GSK2282512A 1 Group | 15 | 423 | 3.5% |
| GSK2282512A 2 Group | 13 | 424 | 3.1% |
| GSK2282512A 3 Group | 7 | 425 | 1.6% |
| Victoria Strain FluLaval Group | 3 | 213 | 1.4% |
| Yamagata Strain FluLaval Group | 7 | 218 | 3.2% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| GSK2282512A 1 Group | 294 of 417 |
| GSK2282512A 2 Group | 286 of 421 |
| GSK2282512A 3 Group | 284 of 422 |
| Victoria Strain FluLaval Group | 127 of 208 |
| Yamagata Strain FluLaval Group | 113 of 216 |
Most frequent serious adverse event terms
| Event term | Organ system | GSK2282512A 1 Group | GSK2282512A 2 Group | GSK2282512A 3 Group | Victoria Strain FluLaval Group | Yamagata Strain FluLaval Group |
|---|---|---|---|---|---|---|
| Angina unstable | Cardiac disorders | 1 of 423 | 0 of 424 | 0 of 425 | 1 of 213 | 0 of 218 |
| Coronary artery disease | Cardiac disorders | 0 of 423 | 0 of 424 | 1 of 425 | 0 of 213 | 1 of 218 |
| Myocardial infarction | Cardiac disorders | 1 of 423 | 1 of 424 | 0 of 425 | 0 of 213 | 0 of 218 |
| Urinary tract infection | Infections and infestations | 0 of 423 | 1 of 424 | 1 of 425 | 0 of 213 | 0 of 218 |
| Hip fracture | Injury, poisoning and procedural complications | 0 of 423 | 0 of 424 | 0 of 425 | 1 of 213 | 1 of 218 |
| Cerebrovascular disorder | Nervous system disorders | 1 of 423 | 0 of 424 | 1 of 425 | 0 of 213 | 0 of 218 |
| Renal failure chronic | Renal and urinary disorders | 1 of 423 | 1 of 424 | 0 of 425 | 0 of 213 | 0 of 218 |
| Cardiac failure | Cardiac disorders | 1 of 423 | 0 of 424 | 0 of 425 | 0 of 213 | 0 of 218 |
| Cardiac failure congestive | Cardiac disorders | 1 of 423 | 0 of 424 | 0 of 425 | 0 of 213 | 0 of 218 |
| Cardiogenic shock | Cardiac disorders | 1 of 423 | 0 of 424 | 0 of 425 | 0 of 213 | 0 of 218 |
Most frequent non-serious adverse event terms
| Event term | Organ system | GSK2282512A 1 Group | GSK2282512A 2 Group | GSK2282512A 3 Group | Victoria Strain FluLaval Group | Yamagata Strain FluLaval Group |
|---|---|---|---|---|---|---|
| Pain | General disorders | 260 of 417 | 245 of 421 | 245 of 422 | 93 of 208 | 89 of 216 |
| Muscle aches | General disorders | 113 of 417 | 105 of 421 | 113 of 422 | 52 of 208 | 40 of 216 |
| Headache | General disorders | 93 of 417 | 87 of 421 | 91 of 422 | 41 of 208 | 49 of 216 |
| Fatigue | General disorders | 92 of 417 | 86 of 421 | 93 of 422 | 45 of 208 | 37 of 216 |
| Gastrointestinal adverse event(s) | General disorders | 43 of 417 | 35 of 421 | 39 of 422 | 21 of 208 | 15 of 216 |
| Shivering | General disorders | 39 of 417 | 37 of 421 | 35 of 422 | 16 of 208 | 13 of 216 |
| Joint pain at other location than injection site | General disorders | 27 of 417 | 27 of 421 | 34 of 422 | 17 of 208 | 15 of 216 |
Serious events with the highest arm-level rate: angina unstable (0.5%), gastrointestinal mucosal disorder (0.5%), upper gastrointestinal haemorrhage (0.5%), fracture displacement (0.5%), hip fracture (0.5%).
The registry records serious adverse-event counts as affected participants and participants at risk in each group: GSK2282512A Lot 1, 15 of 423; Lot 2, 13 of 424; Lot 3, 7 of 425; FluLaval-VB, 3 of 213; and FluLaval-YB, 7 of 218. For other adverse events, the recorded counts are 294 of 417; 286 of 421; 284 of 422; 127 of 208; and 113 of 216, respectively. These are descriptive registry counts, not adjusted comparisons.
The groups differed in their recorded at-risk counts, and the registry record does not provide a common follow-up duration or further detail about event ascertainment in the registry record. No statistical comparison, confidence interval, or causal attribution should be inferred from the counts alone. The term “serious” identifies a safety category; it does not mean that every event was caused by a vaccine.
The registry lists angina unstable, gastrointestinal mucosal disorder, upper gastrointestinal haemorrhage, fracture displacement, hip fracture, and hypoaesthesia at 0.5% each among the top serious terms. The underlying event counts and additional context are not reported in the registry record. Death figures are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The trial’s registry entry describes a randomized, double-masked comparison of an investigational quadrivalent influenza vaccine with two FluLaval vaccines in adults. It records a primary immunogenicity endpoint based on geometric mean antibody titers against four influenza strains at Day 0 and Day 21, and it describes three GSK2282512A lot groups. These registry entries explain what the study was designed to examine; they do not establish the results of the antibody comparisons.
The primary outcome values and confidence intervals are not reported in the registry record. Therefore, the size, direction, and precision of any antibody response cannot be stated from the available record. The registry’s description of a reference cutoff value of 1:10 does not, by itself, demonstrate that participants reached that value or that a particular group performed better.
In general, an antibody-titer endpoint is a laboratory measure of immunogenicity. It is not identical to a clinical outcome such as influenza illness, and it does not establish an individual’s protection. The record lists seroprotection and safety outcomes as secondary measures, but numerical results for those outcome measures are not reported in the registry record.
The listed safety counts describe events recorded in the groups; they do not show whether an event was caused by vaccination. Interpreting comparative safety requires context about follow-up, event definitions, completeness of ascertainment, and uncertainty. Those details are not reported in the registry record.
The completed status and enrollment figure do not substitute for outcome estimates. Nor does a planning illustration establish observed efficacy, observed power, or the success of a particular comparison. The defensible interpretation is limited to the recorded design, endpoint definitions, analysis-population description, and safety counts. Comparative conclusions beyond those details are not supported by the registry record.
13. Why This Trial Matters Statistically
This trial is statistically interesting because its immunogenicity question involves multiple influenza strains, more than one time point, and three investigational vaccine lots alongside two comparator vaccines. That structure makes it important to distinguish a set of endpoint measurements from a single treatment effect. A clear estimand and prespecified analysis strategy are needed to explain which contrast is primary and how results across strains and lots should be interpreted.
The endpoint also illustrates why the scale of measurement matters. Antibody titers are summarized as geometric means, a method suited in general to multiplicative measurements. Understanding the estimate requires attention to its confidence interval and to the analysis scale, not just a comparison of isolated point estimates. Numerical estimates and intervals are not reported in the registry record, so the precision and comparative pattern cannot be assessed.
The inclusion of lot-specific groups raises a distinct consistency question. Comparing lots is not automatically the same as comparing a vaccine with an active comparator, and conclusions depend on the prespecified criteria and analysis. The registry describes an objective of evaluating lot-to-lot consistency, but the consistency results and decision criteria are not reported in the registry record.
Finally, the safety listing shows why counts need context. Group-specific affected and at-risk counts are informative descriptions, but follow-up, event definitions, uncertainty, and causal assessment determine what comparisons can support. The record enables readers to identify the intended outcomes and some recorded counts while also revealing how much statistical interpretation depends on details that are not reported.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The registry record describes the trial design and outcomes but does not include numerical primary immunogenicity estimates or their confidence intervals. This prevents assessment of the magnitude, direction, and precision of the primary endpoint results. It also does not provide a single primary contrast across the four strains and multiple time points, limiting direct comparative interpretation.
The analysis population is described as an According-To-Protocol immunogenicity cohort, but its size and exclusions are not reported in the registry record. The full statistical analysis plan, handling of missing measurements, baseline adjustment, and sensitivity analyses are also not reported. These omissions make it difficult to assess how analysis choices may affect the estimates.
Although the trial is described as randomized and double-masked, the allocation and masking procedures are not detailed in the registry record. Details of participant flow, follow-up completeness, and the timing and ascertainment of adverse events are also not reported. Without these details, the safety counts cannot be interpreted as fully contextualized comparisons.
The registry describes a lot-to-lot consistency objective but does not report its criteria or results. It lists multiple outcome measures, while multiplicity procedures are not reported in the registry record. The record’s planning illustration is not the trial’s own design justification; that justification is not reported in the registry record. These limitations restrict what can be concluded from the recorded information, regardless of the completed status.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study to Evaluate the Safety and Immunogenicity of GSK Biologicals' Seasonal Influenza Vaccine in Adults — NCT01196975.
- Registry record last updated 2018-09-21; status last verified 2016-09.
- Results first posted 2012-12-24.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
This completed phase 3 study was randomized, double-masked, and parallel-group, with 1707 participants enrolled. Adults received one dose of GSK2282512A from one of three lots, FluLaval-VB, or FluLaval-YB. The primary endpoint was geometric mean serum hemagglutination inhibition antibody titer against four influenza strains at Day 0 and Day 21; the primary outcome description identifies Day 21 results for the GSK2282512A group.
The registry describes an According-To-Protocol immunogenicity cohort and lists secondary antibody and safety outcomes. It records group-specific serious and other adverse-event counts, but the primary immunogenicity estimates, confidence intervals, detailed statistical analysis plan, and lot-consistency results are not reported in the registry record. The available record therefore supports a description of the design and measured outcomes, not a numerical conclusion about comparative immunogenicity or safety.