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 Immunogenicity and Safety Study of a Quadrivalent Meningococcal Conjugate Vaccine When Co-administered With Routine Pediatric Vaccines in Healthy Infants and Toddlers in Europe (NCT03547271), a randomized phase 3 study. The primary outcome is Groups 1 and 2: Geometric Mean Titers (GMTs) Against Meningococcal Serogroups A, C, W, and Y.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03547271 |
| Phase | Phase 3 |
| Condition | Meningococcal Infections |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 1660 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sanofi Pasteur, a Sanofi Company |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled healthy infants and toddlers in Europe, with the stated age range of 6 weeks to 18 months. The overall enrollment was 1660. The primary endpoint population was described as Per-Protocol Analysis Set 2, a subset of Full Analysis Set 2; the available description of the analysis population is incomplete in the registry record.
Intervention
For the primary comparison, participants in Group 1 received a 3-dose series of MenACYW conjugate vaccine, administered with routine pediatric vaccines. The listed MenACYW schedule was at 2 months of age, 4 months of age, and 12 to 18 months of age. Routine vaccines included a 10-valent pneumococcal vaccine and a hexavalent DTaP-IPV-HB-Hib vaccine for the stated objective.
Comparator
Group 2 received a 3-dose series of Nimenrix with routine pediatric vaccines. The listed doses were at 2 months of age, 4 months of age, and 12 to 18 months of age. The registry describes this as a licensed meningococcal vaccine comparator. Details of the complete routine-vaccine schedules are not reported in the registry record.
Primary question
The primary objective was to demonstrate non-inferiority of the antibody response to serogroups A, C, W, and Y after the 3-dose MenACYW series compared with the 3-dose licensed vaccine series. Antibody activity was measured by hSBA at 30 days post Dose 3. The registry record does not report the numerical group results, confidence intervals, or the non-inferiority margin, so the primary question cannot be resolved from the posted results described in the record.
3. Trial Design
This was a randomized, quadruple-masked, parallel-group phase 3 study, listed as completed. It enrolled 1660 participants and was sponsored by Sanofi Pasteur, a Sanofi Company. The recorded start date was 2018-12-14 and the primary completion date was 2023-05-17. The condition listed was meningococcal infections.
The main objective compared a 3-dose MenACYW conjugate vaccine series with a 3-dose Nimenrix series, with each given alongside routine pediatric vaccines. The listed meningococcal vaccine doses were at 2 months of age, 4 months of age, and 12 to 18 months of age. The brief summary describes routine co-administration with a 10-valent pneumococcal vaccine and DTaP-IPV-HB-Hib vaccine. The full schedule details are not reported in the registry record.
Two additional groups received MenACYW with different vaccine regimens. Group 3 was described as receiving a 3-dose MenACYW series with routine pediatric vaccines, including a 13-valent pneumococcal vaccine. Group 4 was described as receiving 4 doses of MenACYW, at 2, 4, and 6 months of age and 12 to 18 months of age, with routine vaccines including PCV13. The posted arm descriptions are truncated, so further schedule detail is not reported in the registry record.
The secondary objectives included comparing antibody responses after 2 doses in infancy and describing responses to meningococcal and routine pediatric vaccine antigens. Listed secondary measures included antibody titers, seroresponse, and geometric mean concentrations for selected routine-vaccine antibodies. The registry lists 18 outcome measures and 8 analyses, but does not provide a complete statistical analysis plan in the 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 1660 participants were enrolled in this study.
Overall Study
| Stage | Group 1: MenACYW | Group 2: Nimenrix | Group 3: MenACYW | Group 4: MenACYW |
|---|---|---|---|---|
| STARTED | 714 | 726 | 112 | 108 |
| Safety Analysis Set (SafAS) | 696 | 706 | 112 | 108 |
| COMPLETED | 681 | 691 | 106 | 104 |
| NOT COMPLETED | 33 | 35 | 6 | 4 |
Reasons for not completing this period:
| Reason | Group 1: MenACYW | Group 2: Nimenrix | Group 3: MenACYW | Group 4: MenACYW |
|---|---|---|---|---|
| Adverse Event | 1 | 1 | 0 | 0 |
| Protocol deviation | 5 | 7 | 3 | 0 |
| Withdrawal by Parent/Guardian | 24 | 24 | 2 | 4 |
| Lost to Follow-up | 3 | 3 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Per-Protocol Analysis Set 2 (PPAS2) was a subset of Full Analysis Set 2 (FAS2). The FAS2 included the subset of randomized participants who received at least 1 dose of the study vaccine at booster vaccination and had a valid post-booster vaccination blood sample result. Only participants with data collected for each specific serogroup are reported.
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: All randomized participants included study participants for whom an injection group had been allocated.
| Characteristic | Unit | Group 1: MenACYW | Group 2: Nimenrix | Group 3: MenACYW | Group 4: MenACYW | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 714 | 726 | 112 | 108 | 1660 | |
| Age, Continuous | Days | 72.6 (SD 12.2) | 72.4 (SD 12.1) | 62.5 (SD 7.12) | 63.3 (SD 7.93) | 71.2 (SD 12.1) |
| Sex: Female, Male: Female | Participants | 355 | 378 | 45 | 58 | 836 |
| Sex: Female, Male: Male | Participants | 359 | 348 | 67 | 50 | 824 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | Participants | 0 | 0 | 1 | 0 | 1 |
| Race/Ethnicity, Customized: Asian | Participants | 2 | 1 | 4 | 2 | 9 |
| Race/Ethnicity, Customized: Black or African American | Participants | 0 | 0 | 1 | 3 | 4 |
| Race/Ethnicity, Customized: Native Hawaiian or Other Pacific Islander | Participants | 0 | 1 | 0 | 0 | 1 |
| Race/Ethnicity, Customized: White | Participants | 693 | 699 | 106 | 101 | 1599 |
| Race/Ethnicity, Customized: Not Reported | Participants | 13 | 16 | 0 | 1 | 30 |
| Race/Ethnicity, Customized: Unknown | Participants | 2 | 3 | 0 | 0 | 5 |
| Race/Ethnicity, Customized: Multiple origin | Participants | 4 | 6 | 0 | 1 | 11 |
6. Primary Endpoint
The registry lists the primary outcome as Groups 1 and 2: Geometric Mean Titers (GMTs) Against Meningococcal Serogroups A, C, W, and Y, measured over At 30 days post Dose 3 [12 to 18 months of age (MoA)].
| 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 geometric mean titer (GMT) of functional antibody activity against meningococcal serogroups A, C, W, and Y. Activity was assessed using a serum bactericidal assay with human complement (hSBA), at 30 days post Dose 3, after the dose given at 12 to 18 months of age. The stated comparison is between Groups 1 and 2: MenACYW and Nimenrix, respectively.
A GMT summarizes antibody titers across participants using a geometric rather than arithmetic average. In general, this approach is useful for titers that are distributed on a multiplicative scale; large values do not influence the summary in the same way they can influence an arithmetic mean. A confidence interval expresses uncertainty around an estimated group summary. These general properties do not establish whether one vaccine met the study’s non-inferiority objective.
The registry describes the endpoint and its 95% confidence interval, but does not report the numerical GMT estimates or their confidence limits. The non-inferiority margin and the numerical comparison are also not reported in the registry record. Therefore, the endpoint definition can be described, but its result and its precision cannot be interpreted from the information in the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary question concerns whether the antibody response after MenACYW was non-inferior to the response after Nimenrix when each was given with routine pediatric vaccines. The endpoint was hSBA GMT against serogroups A, C, W, and Y, measured at 30 days post Dose 3. The registry record states this objective, but does not report numerical results for either group, a between-group estimate, confidence limits, or the non-inferiority margin.
That omission limits what can be concluded statistically. Non-inferiority is assessed by comparing an estimated treatment contrast with a prespecified margin. The margin defines how much lower the response could be while still meeting the study’s criterion. Without the margin and the comparison estimate with its uncertainty, the objective cannot be judged as met or unmet using the registry information. No conclusion about the direction or size of the primary contrast is supported by the available record.
The endpoint is one part of a broader immunogenicity assessment. The registry lists GMTs, proportions reaching specified antibody titer thresholds, seroresponse, and geometric mean concentrations for selected routine-vaccine antibodies. These outcomes address different features of antibody response and should not be treated as interchangeable. The record also identifies multiple groups and outcome measures, so results from a particular group or measure would not automatically answer the primary comparison.
The posted safety figures describe serious adverse events and other adverse events by group. Group 1 lists 51 participants with serious adverse events among 696 at risk, and Group 2 lists 57 among 706. Group 3 lists 8 among 112, and Group 4 lists 3 among 108. Other adverse events are listed for 678 of 696 in Group 1, 680 of 706 in Group 2, 107 of 112 in Group 3, and 103 of 108 in Group 4. No deaths are listed in any group. These are descriptive counts; the registry record does not report a statistical comparison of safety between groups.
The study is recorded as completed, but completion status does not itself indicate what the antibody results were. Numerical primary results and a full account of the analysis are not reported in the registry record. Interpretation should therefore remain limited to the design, endpoint definition, and descriptive safety information that the record states.
9. Statistical Methods Explained
What does a geometric mean titer represent?
A titer is a measure of the antibody activity detected in a sample. For this study, functional antibody activity against meningococcal serogroups A, C, W, and Y was assessed using hSBA. The GMT combines participant titers into a group summary using a geometric mean. In general, geometric means are suited to measurements that vary multiplicatively and can be strongly right-skewed. They are commonly interpreted on a logarithmic scale for statistical analysis, then expressed back on the original scale for presentation. The registry record does not state the exact model or calculation procedure used for the primary GMT analysis.
How should the confidence interval be read?
A confidence interval represents uncertainty around an estimated quantity under the statistical method used. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. The primary endpoint is described with a 95% confidence interval, but the interval limits are not reported in the registry record. Consequently, neither the estimate’s precision nor the range of values compatible with the posted analysis can be assessed from the stated information.
What does non-inferiority mean statistically?
In a non-inferiority study, the aim is not simply to show that two groups have identical responses. Instead, the comparison asks whether the response under the intervention is not worse than the comparator by more than a prespecified acceptable amount. That amount is the non-inferiority margin. A decision depends on the contrast, its uncertainty, the margin, and the specified decision rule. The registry record states the non-inferiority objective but does not report the margin, the numerical contrast, or the decision rule. It is therefore not possible to assess non-inferiority from the information available in the record.
Why use hSBA?
The registry describes hSBA as a serum bactericidal assay using human complement and identifies its measure as functional meningococcal antibody activity. In general, an assay of functional activity provides a laboratory measure of antibody-related bacterial killing under assay conditions. It is an immunogenicity measure, not a direct count of clinical meningococcal infections. The primary endpoint is therefore an antibody response outcome rather than a clinical disease outcome.
How do the groups fit the primary question?
The primary comparison is identified as Groups 1 and 2. Group 1 received MenACYW and Group 2 received Nimenrix, each in a 3-dose schedule described as being given with routine pediatric vaccines. Groups 3 and 4 also received MenACYW but had different vaccine regimens; Group 4 is described as receiving 4 doses. Their outcomes may inform other questions listed in the study objectives, but they are not the stated primary comparison of the 3-dose series. The registry record does not provide a complete account of how all groups were incorporated into each analysis.
What is an analysis population?
The primary outcome description identifies Per-Protocol Analysis Set 2 as a subset of Full Analysis Set 2. It says the Full Analysis Set 2 included a subset of randomized participants who received at least 1 dose of study vaccine at booster vaccination and had a valid post-booster blood sample result. The description is truncated after that point. In general, a per-protocol analysis set applies eligibility and protocol-adherence criteria, while a full analysis set is intended to retain a broader randomized group under defined conditions. The detailed inclusion criteria, exclusions, and handling of missing samples are not reported in the registry record.
What do the planning assumptions mean?
The registry’s sample-size assumptions describe planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. These are planning illustrations, not observed power, and they do not establish the study’s original design rationale. The registry record does not report the sample-size justification, the numerical planning estimates, or whether those illustrations were part of the original protocol.
In general, statistical power is a design concept: it describes how often a specified analysis would detect an effect under stated assumptions. It is not a property that can be read directly from a completed trial’s observed result. A planning calculation based on an observed effect is particularly different from a prospective justification because the observed effect is known only after data are collected. The assumptions alone do not show whether the study had adequate power for its non-inferiority objective.
Why can over-dispersion matter?
General note: for outcomes such as counts or proportions, variability may be greater than a simple model assumes. Over-dispersion means that the observed variation exceeds the model’s expected variation. If it is ignored where present, uncertainty estimates can be too small and statistical conclusions can be overstated. The primary endpoint is a GMT, and the registry does not report enough detail to determine whether over-dispersion was assessed or relevant to a particular analysis. No specific model should be inferred from the endpoint description alone.
10. Multiplicity, Missing Data and Analysis Populations
The study lists 18 outcome measures and 8 analyses. The stated objectives span antibody responses against four meningococcal serogroups, multiple vaccine groups and schedules, titer thresholds, seroresponse, and antibody concentrations for routine pediatric vaccines. Multiple outcomes can create a multiplicity issue: when many hypotheses are tested, the chance of at least one apparently unusual result can increase. Statistical approaches can address that issue by defining a testing hierarchy or adjusting inference, but the registry record does not report whether such methods were used.
The primary endpoint description identifies Groups 1 and 2 and gives the assessment time as 30 days post Dose 3. The record does not report the complete hierarchy of primary and secondary analyses, the number of primary hypotheses, or any adjustment strategy. The registry’s note that the primary outcome has several categories or time points and is not reduced to one comparison means there is no single numerical comparison to interpret in the record.
Missing-data handling is also not fully described. The primary analysis population is named as Per-Protocol Analysis Set 2, a subset of Full Analysis Set 2, and the record gives part of the Full Analysis Set 2 definition, including receipt of at least 1 dose at booster vaccination and a valid post-booster blood sample result. The remainder of that definition and the per-protocol criteria are not reported in the registry record. The numbers of participants excluded from each analysis, reasons for missing measurements, and any imputation or sensitivity analyses are not reported in the registry record.
These details matter because analysis-population rules and missing-data assumptions can affect the estimated antibody response and its uncertainty. Their absence does not show that the analyses were inappropriate; it means that the analysis cannot be fully evaluated from the registry record.
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 |
|---|---|---|---|
| Group 1: MenACYW | 51 | 696 | 7.3% |
| Group 2: Nimenrix | 57 | 706 | 8.1% |
| Group 3: MenACYW | 8 | 112 | 7.1% |
| Group 4: MenACYW | 3 | 108 | 2.8% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Group 1: MenACYW | 0 of 696 |
| Group 2: Nimenrix | 0 of 706 |
| Group 3: MenACYW | 0 of 112 |
| Group 4: MenACYW | 0 of 108 |
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 |
|---|---|
| Group 1: MenACYW | 678 of 696 |
| Group 2: Nimenrix | 680 of 706 |
| Group 3: MenACYW | 107 of 112 |
| Group 4: MenACYW | 103 of 108 |
Most frequent serious adverse event terms
| Event term | Organ system | Group 1: MenACYW | Group 2: Nimenrix | Group 3: MenACYW | Group 4: MenACYW |
|---|---|---|---|---|---|
| Bronchitis | Infections and infestations | 6 of 696 | 5 of 706 | 0 of 112 | 0 of 108 |
| Pneumonia | Infections and infestations | 1 of 696 | 5 of 706 | 2 of 112 | 2 of 108 |
| Gastroenteritis | Infections and infestations | 3 of 696 | 5 of 706 | 0 of 112 | 0 of 108 |
| Influenza | Infections and infestations | 3 of 696 | 4 of 706 | 0 of 112 | 0 of 108 |
| Bronchiolitis | Infections and infestations | 2 of 696 | 2 of 706 | 2 of 112 | 0 of 108 |
| Laryngitis | Infections and infestations | 2 of 696 | 2 of 706 | 0 of 112 | 0 of 108 |
| Respiratory Syncytial Virus Bronchiolitis | Infections and infestations | 0 of 696 | 1 of 706 | 1 of 112 | 2 of 108 |
| Interstitial Lung Disease | Respiratory, thoracic and mediastinal disorders | 1 of 696 | 3 of 706 | 0 of 112 | 0 of 108 |
| Otitis Media | Infections and infestations | 1 of 696 | 2 of 706 | 0 of 112 | 0 of 108 |
| Pyelonephritis | Infections and infestations | 1 of 696 | 2 of 706 | 0 of 112 | 0 of 108 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Group 1: MenACYW | Group 2: Nimenrix | Group 3: MenACYW | Group 4: MenACYW |
|---|---|---|---|---|---|
| Irritability | Psychiatric disorders | 600 of 696 | 608 of 706 | 91 of 112 | 86 of 108 |
| Crying | General disorders | 579 of 696 | 579 of 706 | 74 of 112 | 75 of 108 |
| Injection Site Pain | General disorders | 562 of 696 | 566 of 706 | 88 of 112 | 76 of 108 |
| Somnolence | Nervous system disorders | 529 of 696 | 545 of 706 | 67 of 112 | 75 of 108 |
| Injection Site Erythema | General disorders | 537 of 696 | 520 of 706 | 61 of 112 | 58 of 108 |
| Injection Site Swelling | General disorders | 422 of 696 | 417 of 706 | 41 of 112 | 47 of 108 |
| Decreased Appetite | Metabolism and nutrition disorders | 389 of 696 | 372 of 706 | 60 of 112 | 58 of 108 |
| Pyrexia | General disorders | 375 of 696 | 345 of 706 | 46 of 112 | 42 of 108 |
| Vomiting | Gastrointestinal disorders | 196 of 696 | 197 of 706 | 25 of 112 | 27 of 108 |
| Injection Site Bruising | General disorders | 110 of 696 | 124 of 706 | 3 of 112 | 4 of 108 |
Serious events with the highest arm-level rate: pneumonia (1.9%), respiratory syncytial virus bronchiolitis (1.9%), bronchiolitis (1.8%), lymphatic malformation (0.9%), craniocerebral injury (0.9%).
The registry lists serious adverse events and other adverse events by group, with participants at risk and participants affected. For serious adverse events, the entries are 51 of 696 in Group 1, 57 of 706 in Group 2, 8 of 112 in Group 3, and 3 of 108 in Group 4. For other adverse events, the entries are 678 of 696 in Group 1, 680 of 706 in Group 2, 107 of 112 in Group 3, and 103 of 108 in Group 4. The record lists 0 deaths in each group.
These figures are descriptive group counts. They should not be read as adjusted comparisons or as evidence of a causal difference between vaccines. The group sizes and regimens differ, especially for Groups 3 and 4, and the registry record does not report a statistical comparison of adverse-event outcomes. The record also does not give the full definitions or observation periods for these summary categories.
The listed serious adverse-event terms include Pneumonia (1.9%), Respiratory Syncytial Virus Bronchiolitis (1.9%), Bronchiolitis (1.8%), Lymphatic Malformation (0.9%), Craniocerebral Injury (0.9%), and Thrombocytopenia (0.9%). These are presented as top serious terms; their denominators and group-specific distribution are not reported in the registry record. The percentages should therefore be read as registry-listed descriptive figures, not as comparative risks.
12. What the Result Does, and Does Not, Mean
The study was designed to evaluate immunogenicity in healthy infants and toddlers in Europe, focusing on antibody responses after meningococcal vaccination given with routine pediatric vaccines. Its primary objective was a non-inferiority comparison of a 3-dose MenACYW series with a 3-dose licensed meningococcal vaccine series. The endpoint was functional antibody activity measured by hSBA at 30 days post Dose 3.
The registry record does not report the numerical primary endpoint results, confidence interval limits, non-inferiority margin, or a decision against that margin. Thus, it does not establish from the information stated whether the primary non-inferiority objective was met. The endpoint description alone cannot indicate which group had the higher response, how large any difference was, or how precisely it was estimated.
The antibody endpoint is a laboratory immunogenicity measure. In general, antibody responses can help characterize immune response, but a measured titer is not itself a count of infections or a direct estimate of clinical disease outcomes. The registry record’s primary objective should not be interpreted as a direct comparison of meningococcal disease incidence.
The record also lists safety counts and several secondary antibody outcomes. Those listings add descriptive context but do not replace the missing primary comparison. The safety figures are not presented as adjusted group comparisons, and results for secondary outcomes are not numerically included in the registry record stated for this analysis. Absence of those numerical results from the registry record is not evidence that an outcome was absent or that a treatment had no effect.
Accordingly, the supported interpretation is narrow: this was a randomized phase 3 immunogenicity study with a stated non-inferiority objective and a defined hSBA endpoint, alongside descriptive adverse-event reporting. Conclusions about the primary result, clinical protection, or comparative safety require information not reported in the registry record.
13. Why This Trial Matters Statistically
This trial raises several statistical issues common in pediatric vaccine studies. The primary objective is non-inferiority, which requires more than comparing two group averages. Interpretation depends on the chosen margin, the estimated contrast, and its uncertainty. Because the registry record does not report the margin or numerical primary results, readers can identify the intended inferential question but cannot evaluate the non-inferiority conclusion.
The study also evaluates antibody responses across multiple meningococcal serogroups, vaccine schedules, and routine-vaccine antigens. Such breadth can be useful for describing immunogenicity, but it makes clear definitions of primary and secondary questions important. The registry lists 18 outcome measures and 8 analyses, while the complete multiplicity approach is not reported in the registry record. Separating confirmatory conclusions from descriptive outcomes is essential when many responses are assessed.
Analysis populations are another key issue. The primary endpoint is linked to a per-protocol set defined as a subset of a full analysis set, and the latter description is incomplete in the registry record. In vaccine studies, eligibility, protocol adherence, and availability of valid blood samples can determine who contributes to an endpoint estimate. Transparent population definitions and missing-data methods allow readers to understand how those choices shape results.
Finally, the trial distinguishes immunogenicity from clinical outcomes. An hSBA GMT summarizes assay-measured functional antibody activity; it is not a direct clinical disease endpoint. That distinction is important when interpreting what a vaccine study’s statistical result can establish. The design and endpoint are stated, but the absence of numerical efficacy-related results constrains interpretation of the primary objective.
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 primary limitation for interpreting the stated objective is that the registry record does not report the numerical GMT estimates, confidence limits, between-group contrast, or non-inferiority margin. Without these, the main statistical result cannot be assessed. The outcome description also notes that the primary outcome has several categories or time points and is not reduced to one comparison, leaving no single numerical primary comparison in the record.
The analysis-population description is incomplete. It identifies Per-Protocol Analysis Set 2 and gives part of the Full Analysis Set 2 definition, but the remainder of the criteria is not reported in the registry record. The numbers excluded, reasons for missing measurements, and handling of missing data are also not reported. These omissions make it difficult to judge how representative the analyzed participants were of the randomized groups.
The trial included groups with different vaccine schedules, including a 4-dose MenACYW group, and descriptions of some routine-vaccine schedules are truncated. Therefore, the listed groups should not be treated as if they differed only by meningococcal vaccine. Full schedule details and the analysis plan are not reported in the registry record.
Further limitations of interpretation include the absence of reported multiplicity procedures and detailed statistical methods. The registry lists multiple outcomes and analyses but does not state a complete testing hierarchy, model specifications, or sensitivity analyses. The safety information is descriptive and lacks a reported comparative analysis. These are limitations of the available registry record; they do not, by themselves, establish that the underlying trial lacked those procedures.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Immunogenicity and Safety Study of a Quadrivalent Meningococcal Conjugate Vaccine When Co-administered With Routine Pediatric Vaccines in Healthy Infants and Toddlers in Europe — NCT03547271.
- Registry record last updated 2025-03-03; status last verified 2025-02.
- Results first posted 2025-01-22.
- 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
NCT03547271 is a completed randomized, quadruple-masked, parallel-group phase 3 study sponsored by Sanofi Pasteur, a Sanofi Company. It enrolled 1660 healthy infants and toddlers in Europe. The primary objective was to compare antibody responses after 3 doses of MenACYW conjugate vaccine or Nimenrix, each administered with routine pediatric vaccines.
The primary endpoint was hSBA geometric mean titer against meningococcal serogroups A, C, W, and Y at 30 days post Dose 3. The registry record does not report the numerical primary results or non-inferiority margin. It lists adverse-event counts by group, with 0 deaths in each group, but does not report a statistical comparison of safety. Multiple secondary immunogenicity outcomes are listed; their complete results and analysis methods are not reported in the registry record.