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 Study of Menactra® in Healthy Subjects at 9 Months and Concomitantly With Pentacel® at 15 to 18 Months of Age (NCT01659996), a randomized phase 4 study. The primary outcome is Percentage of Study Participants Achieving Menactra Response for Meningococcal Serogroups A, C, Y, and W-135 Following the Second Menactra Vaccination.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01659996 |
| Phase | Phase 4 |
| Condition | Meningitis, Meningococcal Infection, Diphtheria |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 1394 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sanofi Pasteur, a Sanofi Company |
| Results posted | Yes |
2. Clinical Question
Population
The trial enrolled healthy subjects starting at 9 months of age. The primary antibody assessment used the per-protocol population in the Menactra Vaccine Group and Menactra + Pentacel Vaccine Group. The registry record does not report further eligibility details or the number included in that analysis.
Intervention
Participants in the Menactra Vaccine Group received Menactra at 9 months and again at 15 to 18 months. Participants in the Menactra + Pentacel Vaccine Group received Menactra at 9 months, then Menactra concomitantly with Pentacel at 15 to 18 months.
Comparator
For the primary antibody-response endpoint, the registry record identifies the Menactra Vaccine Group and the Menactra + Pentacel Vaccine Group. A separate Pentacel Vaccine Group received Pentacel at 15 to 18 months, but it is not included in the stated primary endpoint population.
Primary question
Among participants in the stated per-protocol population, what percentage achieved the defined Menactra response to meningococcal serogroups A, C, Y, and W-135 by Day 30 after the second Menactra vaccination? The endpoint was intended to compare antibody responses between the two groups receiving Menactra.
The trial also set out to evaluate antibody responses to other vaccine antigens and to describe safety. Its stated objectives include responses to pertussis antigens and to PRP, tetanus, and diphtheria antigens after Pentacel given with Menactra or alone. These additional objectives address whether immune responses to components of Pentacel differ according to concomitant Menactra administration. The registry record does not report results for those objectives in the information available for this analysis.
The primary question is immunological: it concerns a prespecified antibody-response definition, rather than a clinical diagnosis or a direct measure of disease prevention. The registry record describes the measurement and timing but does not provide the observed group percentages, the difference between groups, or a confidence interval. Consequently, it does not support a conclusion about the magnitude or precision of the primary comparison.
3. Trial Design
This was a Phase 4, randomized, parallel-group trial with no masking reported. The registry record lists enrollment of 1394 and status as completed. The study began in 2012-07, with primary completion in 2014-11. It was sponsored by Sanofi Pasteur, a Sanofi Company. These design details describe how the study was organized; they do not by themselves establish the results of the antibody or safety assessments.
Three groups are described. The Menactra Vaccine Group received Menactra at 9 months and at 15 to 18 months. The Menactra + Pentacel Vaccine Group received Menactra at 9 months, followed by Menactra and Pentacel concomitantly at 15 to 18 months. The Pentacel Vaccine Group received Pentacel at 15 to 18 months. The primary endpoint population includes the first two groups, as defined in the registry record. The Pentacel-only group is included in the safety information but not in that stated primary population.
Random allocation can help balance participant characteristics across groups, on average, but the registry record does not report the allocation sequence, concealment procedures, or group-specific baseline characteristics. With masking listed as none, participants and trial personnel were not masked according to the registry entry. The record does not specify whether laboratory staff assessing antibody titers were masked.
The primary endpoint was assessed on Day 30 after the second Menactra vaccination. Antibodies to serogroups A, C, Y, and W-135 were measured using a serum bactericidal assay with human complement. The record describes the endpoint as a percentage meeting a response definition and identifies the per-protocol population for the primary assessment. It does not report the number analyzed in each group, how departures from protocol were handled, or whether an intention-to-treat analysis was also conducted. The record's sample-size justification 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: A total of 1394 participants were enrolled for the study, data on 1288 participants who met all the inclusion and none of the exclusion criteria and who completed the vaccination schedule are presented in this report.
Overall Study
| Stage | Menactra Vaccine Group | Menactra + Pentacel Vaccine Group | Pentacel Vaccine Group |
|---|---|---|---|
| STARTED | 421 | 395 | 472 |
| COMPLETED | 413 | 388 | 461 |
| NOT COMPLETED | 8 | 7 | 11 |
Reasons for not completing this period:
| Reason | Menactra Vaccine Group | Menactra + Pentacel Vaccine Group | Pentacel Vaccine Group |
|---|---|---|---|
| Protocol Violation | 3 | 3 | 3 |
| Lost to Follow-up | 1 | 3 | 2 |
| Adverse Event | 0 | 0 | 1 |
| Withdrawal by Subject | 4 | 1 | 5 |
Analysis population for the primary outcome, as defined in the registry: Antibody titers to the meningococcal serogroups were assessed in the Per-protocol population of the participants in Menactra Vaccine Group and Menactra + Pentacel Vaccine Group.
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.
Population: The demographic and baseline characteristics are in the safety analysis set (SafAS)
| Characteristic | Unit | Menactra Vaccine Group | Menactra + Pentacel Vaccine Group | Pentacel Vaccine Group | Total |
|---|---|---|---|---|---|
| Participants analysed | 421 | 395 | 472 | 1288 | |
| Age, Categorical: <=18 years | Participants | 421 | 395 | 472 | 1288 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 | 0 |
| Age, Continuous | Days | 284.5 (SD 10.8) | 284.6 (SD 10.6) | 483.9 (SD 30.3) | 353.6 (SD 96.8) |
| Sex: Female, Male: Female | Participants | 219 | 171 | 232 | 622 |
| Sex: Female, Male: Male | Participants | 202 | 224 | 240 | 666 |
| Region of Enrollment: United States | Participants | 421 | 395 | 472 | 1288 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Study Participants Achieving Menactra Response for Meningococcal Serogroups A, C, Y, and W-135 Following the Second Menactra Vaccination, measured over Day 30 post second Menactra vaccination.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants achieving a Menactra response to meningococcal serogroups A, C, Y, and W-135 after the second Menactra vaccination. Antibody titers were measured by a serum bactericidal assay using human complement, described in the registry as hSBA or SBA-HC. The assessment time was Day 30 after that vaccination.
The response definition depends on the participant's baseline titer. A participant whose baseline titer was less than 1:8 was counted as a responder if the measured titer reached at least 1:8. A participant whose baseline titer was at least 1:8 was counted as a responder if the titer increased at least fourfold. Thus, the endpoint combines attaining a specified threshold among participants below it at baseline with a substantial rise among participants already at or above it.
This kind of endpoint is used to summarize an immune response in a way that accounts for baseline antibody levels. It turns titer measurements into a responder classification, then expresses the result as a percentage of participants. As a general statistical point, that percentage describes the proportion meeting the defined criterion in the analyzed group; it does not reveal the full distribution of antibody titers or how close individual measurements were to the threshold.
The registry record does not report the observed response percentages, group contrast, confidence interval, or test result for this endpoint. The definition and assessment time are reported, but the size and precision of the primary result are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the primary outcome and the groups intended for its comparison, but does not include the observed primary endpoint results. It therefore does not report how many participants met the Menactra response definition in either group, the percentage in each group, or the difference between those percentages. A numerical estimate of the comparative antibody response cannot be interpreted from the record details.
That absence matters because the endpoint is a binary responder outcome summarized as a percentage. A percentage alone would describe the observed frequency of response in an analyzed group; a comparison between groups would require the group-specific estimates and an uncertainty measure. A confidence interval, if reported, would show the range of effect sizes reasonably compatible with the data under the analysis assumptions. Without those estimates, the direction, magnitude, and precision of the primary comparison are not established by the registry record.
The endpoint applies to the per-protocol population in the Menactra Vaccine Group and Menactra + Pentacel Vaccine Group. A per-protocol analysis is generally focused on participants who met specified protocol requirements. As a general statistical consideration, excluding participants from such an analysis can affect comparability if exclusions are associated with prognosis or treatment experience. The eligibility criteria for this analysis and the number excluded are not reported in the registry record. The record also does not report an intention-to-treat result that could be considered alongside the per-protocol estimate.
The registry lists a randomized design, which is relevant to interpreting between-group comparisons, but randomization alone does not supply the missing result estimate or its uncertainty. The record does not report baseline balance, the exact analysis method, or any adjustment procedure. It is therefore not possible to determine from the listed information whether the reported analysis, if any, accounted for baseline antibody levels beyond the endpoint's response definition.
The safety record gives serious adverse event counts for each group and lists several serious event terms with percentages. These are descriptive figures, not a substitute for the missing primary immune-response comparison. The registry record does not provide enough detail in this summary to judge whether between-group differences in serious events are statistically distinguishable, nor to attribute an event to a particular vaccine. The result should be read as an incomplete account of the stated study objectives: the design, endpoint definition, and some safety counts are available, while the principal antibody-response estimates are not reported in the registry record.
Any sample-size figures presented as planning illustrations should be understood as hypothetical planning quantities, not as observed trial results or observed power. The record describes such illustrations as based on a fraction of the observed effect, but does not report the values needed to interpret a particular illustration in this analysis. A planning calculation cannot fill the gap left by an unreported primary estimate.
9. Statistical Methods Explained
Statistical methods determine how measurements are turned into estimates and how uncertainty is described. The registry record gives some design and endpoint details, but does not report a complete analysis plan. The explanations below distinguish general statistical principles from trial-specific methods documented in the record.
What does randomization contribute?
In general, random allocation aims to make treatment groups comparable with respect to both measured and unmeasured participant characteristics, on average. This supports interpretation of a group contrast as an effect of the assigned treatment strategy, provided that allocation is implemented as intended and follow-up and analysis do not introduce important bias. Randomization does not guarantee identical groups in a particular trial, and does not eliminate uncertainty from sampling. The registry record states that allocation was randomized but does not report the sequence generation or concealment methods, nor does it provide baseline characteristics for assessing the groups.
What does an open-label design imply?
The registry lists masking as none. In general, lack of masking can affect behavior, reporting, follow-up, and decisions about how to classify subjective outcomes. The primary endpoint is based on laboratory antibody titers, which are less dependent on participant reporting than many clinical outcomes. However, the record does not say whether laboratory personnel or analysts were masked to group assignment. The potential for bias therefore cannot be assessed fully from the registry description alone.
How is a responder percentage formed?
The primary outcome classifies each participant according to a baseline-dependent rule. Participants with a baseline titer below 1:8 must reach at least 1:8; those with a baseline titer at least 1:8 must achieve at least a fourfold increase. The percentage is the share of the analyzed population classified as responders. As a general statistical point, converting a continuous titer measurement into a responder category makes the result easier to summarize but discards information about the exact titer and the size of changes that do not meet the rule. A participant just below a response threshold and one with a much lower titer can both be classified as nonresponders.
The endpoint is assessed separately for serogroups A, C, Y, and W-135. The title of the primary measure refers to all four serogroups, but the registry record does not clarify in this summary whether a single combined response criterion or separate serogroup-specific estimates are the basis of the posted result. It states that antibody responses to the serogroups were assessed. The actual estimates and their statistical analysis are not reported in the registry record.
Why report uncertainty around a percentage or contrast?
In general, a confidence interval communicates the statistical uncertainty around an estimated quantity. For a group percentage, it reflects uncertainty in the estimated responder frequency; for a difference between groups, it reflects uncertainty in the contrast. A narrow interval indicates greater precision under the model and assumptions used, while a wide interval indicates less precision. An interval also helps readers judge which effect sizes remain compatible with the observed data. The registry record does not report a confidence interval for the primary endpoint, so its precision cannot be described.
A significance test addresses a different question: whether the observed data are inconsistent with a specified null hypothesis under the model. A p-value does not measure the probability that the null hypothesis is true, nor does it indicate the size or clinical importance of an effect. The registry information does not include a p-value or identify a test for the primary endpoint. No conclusion about statistical significance can be drawn from the endpoint definition alone.
What is the role of the analysis population?
The primary endpoint is assigned to a per-protocol population from the two Menactra groups. In general, per-protocol analysis can describe outcomes among participants who followed key trial requirements, but post-randomization exclusions may weaken the balance created by randomization. An intention-to-treat analysis generally retains participants in their randomized groups and can preserve the initial randomization comparison, although it depends on how missing outcomes are addressed. The registry record does not report the analysis population size, exclusion rules, missing-outcome procedure, or an intention-to-treat analysis.
How should planning calculations be read?
In general, a sample-size calculation uses assumptions about the effect to detect, variability or event frequency, significance level, power, and allocation. The record describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It says the effect for an illustration is a stated fraction of the observed effect. These are planning assumptions, not evidence about the result. Sample-size illustrations are not observed power: observed power is not a useful replacement for interpreting the estimate and its confidence interval after a study has been completed. The record does not report the trial's own sample-size justification.
For a binary outcome, the planning quantity described in the record is participants per arm for a stated power level. Such a figure is conditional on the assumptions used and should not be treated as an observed count or a trial result. The registry record does not report enough of the actual calculation outputs in this summary to interpret particular planning values.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 9 outcome measures and 10 analyses. It describes several immunogenicity objectives involving different meningococcal serogroups and antigens, along with safety objectives. When many outcomes, groups, time points, or statistical tests are considered, the chance of obtaining at least one apparently unusual result can increase. As a general statistical approach, investigators may define a primary comparison in advance and use multiplicity procedures for additional tests, or interpret secondary findings as exploratory. The multiplicity strategy for this trial is not reported in the registry record.
The primary outcome description specifies a per-protocol population, but the registry does not report the number analyzed, the rules for inclusion, or how missing antibody measurements were handled. It also does not report the number of participants with incomplete follow-up or whether missingness differed by group. These details matter because analyses limited to participants with observed measurements can be biased if the likelihood of missing data is related to response or group assignment. In general, missing-data assumptions and sensitivity analyses help readers understand how dependent an estimate is on those assumptions; such procedures are not reported in the registry record.
The registry record does not state whether all listed outcomes were prespecified in a detailed statistical analysis plan or how changes to outcomes or analyses were handled. The sample-size justification is not reported in the registry record. Without a stated multiplicity strategy, readers should avoid treating any single secondary result as confirmatory solely because it appears among the reported outcomes. The absence of these details does not establish that an analysis was inappropriate; it limits what can be assessed from the registry information.
Analysis-population details also affect interpretation. The primary assessment is described for participants in the two Menactra groups who were included in the per-protocol population. The registry record does not say whether any additional populations were analyzed, how deviations from assigned vaccination were treated, or whether sensitivity analyses tested the robustness of the primary comparison.
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 |
|---|---|---|---|
| Menactra Vaccine Group | 13 | 421 | 3.1% |
| Menactra + Pentacel Vaccine Group | 11 | 395 | 2.8% |
| Pentacel Vaccine Group | 1 | 472 | 0.2% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5.00% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Menactra Vaccine Group | 296 of 421 |
| Menactra + Pentacel Vaccine Group | 318 of 395 |
| Pentacel Vaccine Group | 380 of 472 |
Most frequent serious adverse event terms
| Event term | Organ system | Menactra Vaccine Group | Menactra + Pentacel Vaccine Group | Pentacel Vaccine Group |
|---|---|---|---|---|
| Febrile convulsion | Nervous system disorders | 3 of 421 | 1 of 395 | 0 of 472 |
| Croup infectious | Infections and infestations | 0 of 421 | 2 of 395 | 0 of 472 |
| Groin abscess | Infections and infestations | 0 of 421 | 2 of 395 | 0 of 472 |
| Viral infection | Infections and infestations | 1 of 421 | 1 of 395 | 0 of 472 |
| Dehydration | Metabolism and nutrition disorders | 0 of 421 | 2 of 395 | 0 of 472 |
| Aortic valve incompetence | Cardiac disorders | 1 of 421 | 0 of 395 | 0 of 472 |
| Bronchiolitis | Infections and infestations | 1 of 421 | 0 of 395 | 0 of 472 |
| Gastroenteritis | Infections and infestations | 1 of 421 | 0 of 395 | 0 of 472 |
| Neutropenic infection | Infections and infestations | 0 of 421 | 0 of 395 | 1 of 472 |
| Penile abscess | Infections and infestations | 1 of 421 | 0 of 395 | 0 of 472 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Menactra Vaccine Group | Menactra + Pentacel Vaccine Group | Pentacel Vaccine Group |
|---|---|---|---|---|
| Irritability | Psychiatric disorders | 296 of 420 | 284 of 393 | 271 of 463 |
| Injection Site Tenderness | General disorders | 219 of 420 | 242 of 393 | 238 of 463 |
| Crying abnormal | Psychiatric disorders | 222 of 420 | 205 of 393 | 181 of 463 |
| Drowsiness | Nervous system disorders | 209 of 420 | 206 of 393 | 139 of 463 |
| Appetite lost | Metabolism and nutrition disorders | 182 of 420 | 188 of 393 | 163 of 463 |
| Injection Site Erythema | General disorders | 106 of 420 | 152 of 393 | 144 of 463 |
| Injection-site Swelling | General disorders | 63 of 420 | 91 of 393 | 99 of 463 |
| Fever | General disorders | 71 of 421 | 85 of 394 | 57 of 463 |
| Vomiting | Gastrointestinal disorders | 95 of 420 | 68 of 393 | 46 of 472 |
| Upper respiratory tract infection | Infections and infestations | 60 of 421 | 52 of 395 | 50 of 472 |
Serious events with the highest arm-level rate: febrile convulsion (0.7%), croup infectious (0.5%), groin abscess (0.5%), dehydration (0.5%), pneumonia (0.3%).
The registry safety figures list serious adverse events affecting 13 participants in the Menactra Vaccine Group, 11 in the Menactra + Pentacel Vaccine Group, and 1 in the Pentacel Vaccine Group. The corresponding numbers at risk are 421, 395, and 472. These are reported as counts, and the registry record does not give a comparative statistical analysis or confidence intervals for them. Counts alone do not show whether a difference between groups is more than could be explained by chance, and they do not establish that a vaccine caused an event.
The listed serious event terms include febrile convulsion at 0.7%, croup infectious at 0.5%, groin abscess at 0.5%, dehydration at 0.5%, pneumonia at 0.3%, and staphylococcal abscess at 0.3%. These terms and percentages describe events recorded in the registry; they should not be interpreted as comparative risks unless the relevant group-specific denominators, definitions, and analysis are specified. The registry record does not report the attribution of these events to study treatment.
Deaths are not reported in the registry record. The record separately lists other adverse event counts, but the serious-event counts should not be conflated with those broader figures. As a general statistical point, adverse-event comparisons require attention to event definitions, observation periods, denominators, and uncertainty. The registry describes serious adverse events as monitored throughout the trial through Day 30 after the last trial vaccination or vaccinations.
12. What the Result Does, and Does Not, Mean
The available registry information establishes the trial's question, groups, endpoint definition, and some safety counts. It does not establish the observed primary immune-response result. Because response percentages and a comparative estimate are not reported in the registry record, the magnitude, direction, and precision of the primary comparison cannot be stated. This is a limit on interpretation, not evidence that the groups were the same or different.
The endpoint is a laboratory antibody response defined using baseline titers and a threshold or fold-rise criterion. As a general interpretation point, an antibody response is a surrogate or intermediate measurement rather than a direct count of clinical disease outcomes. The primary endpoint definition alone does not show how well the measurement predicts protection from disease, and the registry record does not report a clinical disease comparison for this primary question.
The study also sought to characterize safety and immune responses when Menactra was administered alone or concomitantly with Pentacel. Its three-group design distinguishes Menactra at both vaccination visits, Menactra with Pentacel at the later visit, and Pentacel alone at the later visit. Those strategies answer related but different questions. The registry's stated primary endpoint concerns the two Menactra groups; the Pentacel-only group is not included in that primary population. The record does not report the results needed to assess the additional immunogenicity objectives.
The listed serious adverse event counts are descriptive. They do not, without a comparative analysis and uncertainty estimates, establish whether rates differ across groups or whether any event was caused by treatment. The registry record also does not report deaths. More complete interpretation would require the outcome estimates, analysis populations, missing-data methods, and statistical procedures. Until those are available in the registry record, the design and definitions can be described, but conclusions about comparative immune response or treatment effects cannot be drawn from these entries alone.
13. Why This Trial Matters Statistically
This trial illustrates why a clearly defined endpoint is not the same as a reported result. The registry explains how Menactra response was classified: the rule depends on baseline antibody titers and a Day 30 measurement after the second vaccination. That definition makes the outcome interpretable in principle, but the missing group estimates prevent readers from evaluating the actual response frequencies or their precision.
The trial also demonstrates how intervention timing and concomitant administration shape the estimand, or the precise comparison a study seeks to estimate. The primary comparison is between participants receiving Menactra at both visits and those receiving Menactra at the first visit with Menactra plus Pentacel at the later visit. The Pentacel-only group provides a distinct treatment strategy, but it is not part of the stated primary endpoint population. Keeping these comparisons separate avoids implying that every group addresses the same question.
Statistically, the combination of a per-protocol primary population and a randomized design raises an important interpretive issue: randomization supports comparability at assignment, while exclusions after assignment can alter that balance. The registry record does not report enough analysis-population detail to assess how this issue was handled. Similarly, multiple immunogenicity and safety objectives make the multiplicity strategy relevant, yet it is not reported in the registry record.
The safety counts reinforce the distinction between description and inference. Event counts and percentages can inform what was recorded, but a comparative conclusion also depends on definitions, denominators, follow-up, and uncertainty. Overall, this record is a useful case in separating documented design features from unavailable outcome evidence and in avoiding conclusions that exceed the reported estimates.
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 central limitation for interpreting the primary question is that the registry record does not report the observed responder percentages, a between-group estimate, confidence intervals, or a test result. The endpoint can be described, but its result and precision cannot be assessed from the registry information available.
The primary analysis is described as per-protocol, yet the registry record does not report the criteria for that population, the number analyzed in each group, exclusions after randomization, or a complementary intention-to-treat analysis. It also does not report how missing antibody measurements were handled. These omissions limit assessment of selection bias and the robustness of the primary comparison.
The record lists multiple outcome measures and analyses but does not report a multiplicity strategy or a detailed statistical analysis plan. It does not report the trial's sample-size justification, so the rationale for the planned enrollment cannot be evaluated. It describes planning illustrations based on the observed effect, but those illustrations are not trial outcomes and cannot substitute for estimates with uncertainty.
Although the trial is described as randomized and unmasked, the record does not report allocation-concealment procedures, baseline characteristics, or whether laboratory assessors were masked. The registry's safety summary includes serious-event counts and selected event terms, but not comparative estimates, confidence intervals, or attribution. Deaths are not reported in the registry record. The available details therefore support description of the study framework and selected safety information, but not a complete assessment of efficacy, safety differences, or analytic robustness.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of Menactra® in Healthy Subjects at 9 Months and Concomitantly With Pentacel® at 15 to 18 Months of Age — NCT01659996.
- Registry record last updated 2015-12-15; status last verified 2015-11.
- Results first posted 2015-12-15.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01659996 is a completed Phase 4, randomized, parallel-group trial with no masking reported. Enrollment was 1394. The study evaluated Menactra in healthy subjects beginning at 9 months, including administration with Pentacel at 15 to 18 months.
The primary endpoint was the percentage achieving a defined antibody response to meningococcal serogroups A, C, Y, and W-135 on Day 30 after the second Menactra vaccination. The registry identifies a per-protocol population in the Menactra and Menactra + Pentacel groups. It does not report the primary response estimates or their uncertainty in the information available for this analysis.
Serious adverse event counts are listed for all three groups, along with selected serious event terms and percentages. A comparative safety analysis, deaths, missing-data procedures, multiplicity strategy, and sample-size justification are not reported in the registry record.