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 of V419 Given Concomitantly With Prevnar 13™ and RotaTeq™ (V419-006) (NCT01340937), a randomized phase 3 study. The primary outcome is Geometric Mean Concentration of Antibodies to Polyribosylribitol Phosphate Antigen.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01340937 |
| Phase | Phase 3 |
| Condition | Bacterial Infections, Virus Diseases |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 2808 |
| Arms in the primary outcome | 5 |
| Lead sponsor | Merck Sharp & Dohme LLC |
| Results posted | Yes |
2. Clinical Question
Population
Healthy infants enrolled in a Phase III study. The registry lists enrollment of 2808. For the primary endpoint, the analysis population was restricted to participants who met inclusion criteria, were not protocol violators, had an infant vaccination window of 42 to 84 days after the previous dose, and had an endpoint blood draw 28 to 51 days after dose 3.
Intervention
Three manufacturing lots of V419, identified as Lot A, Lot B, and Lot C, were given at 2, 4, and 6 months of age. The study also evaluated administration alongside Prevnar 13 and RotaTeq.
Comparator
The control group received Pentacel, Prevnar 13, RotaTeq, and Recombivax HB vaccine according to the schedules listed in the registry. The lots were also compared with one another for the primary antibody outcome.
Primary question
At Postdose 3 (Month 7), what were the geometric mean concentrations of antibodies to polyribosylribitol phosphate, and how did the antibody concentrations compare across V419 lots and between the combined V419 lots and control?
The study addressed both lot-to-lot consistency and the immune response observed with V419 given concomitantly with the other named vaccines. These are distinct statistical questions: lot comparisons examine whether responses differ among the three V419 lots, while the combined-lot comparison describes the response relative to the control group. The registry lists a geometric mean concentration endpoint and reported ratios for these comparisons. The record does not state the prespecified margin used to judge lot equivalence or non-inferiority, so the ratios and their confidence intervals can be described, but cannot by themselves establish that a formal criterion was met.
3. Trial Design
This was a randomized, parallel-group Phase III clinical study with active comparators. The official title describes it as partially double-blind; the registry’s masking classification is quadruple. Enrollment was 2808, and the record lists the study as completed. The start date was 2011-05-10 and primary completion was 2012-12-18.
Participants were assigned to V419 Lot A, Lot B, Lot C, or a control regimen. Each V419 lot was administered by intramuscular injection at 2, 4, and 6 months of age. The lot groups also received Prevnar 13 at 2, 4, 6, and 15 months, RotaTeq at 2, 4, and 6 months, and Pentacel at 15 months. The control regimen included Pentacel and Prevnar 13 at 2, 4, 6, and 15 months, RotaTeq at 2, 4, and 6 months, and Recombivax HB vaccine at 2 and 6 months.
The primary endpoint was assessed after dose 3 at Month 7. The registry describes blood sampling for the primary endpoint and defines an analysis population with eligibility, protocol-adherence, vaccination-window, and blood-draw-window criteria. Arm counts for the endpoint differed, and the endpoint analyses therefore do not all include the same number of participants. The reasons for all differences in analyzed counts are not reported in the registry record.
The record lists 33 outcome measures and 112 analyses. It also lists eight secondary response outcomes involving antigens including hepatitis B surface antigen, diphtheria toxin, tetanus toxin, and pertussis antigens. The protocol details for allocation procedures, sample-size justification, interim analyses, and the full 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: The infant series of vaccinations were those administered at 2, 4, and 6 months of age; the toddler vaccinations were those administered at 15 months of age. The Interim Period is the time between the last vaccination of the infant series and the time of administration of the toddler vaccination.
Period 1: Infant Series
| Stage | V419 Lot A | V419 Lot B | V419 Lot C | Control |
|---|---|---|---|---|
| STARTED | 800 | 797 | 809 | 402 |
| COMPLETED | 742 | 737 | 753 | 370 |
| NOT COMPLETED | 58 | 60 | 56 | 32 |
Reasons for not completing this period:
| Reason | V419 Lot A | V419 Lot B | V419 Lot C | Control |
|---|---|---|---|---|
| Other protocol criterion not met | 0 | 1 | 1 | 0 |
| Adverse Event | 0 | 1 | 4 | 0 |
| Death | 2 | 0 | 2 | 0 |
| Lost to Follow-up | 20 | 14 | 12 | 13 |
| Physician Decision | 2 | 3 | 1 | 0 |
| Protocol Violation | 1 | 4 | 4 | 3 |
| Withdrawal by Subject | 33 | 32 | 30 | 15 |
| Randomized but not vaccinated | 0 | 5 | 2 | 1 |
Period 2: Interim Period
| Stage | V419 Lot A | V419 Lot B | V419 Lot C | Control |
|---|---|---|---|---|
| STARTED | 742 | 737 | 753 | 370 |
| COMPLETED | 675 | 658 | 669 | 329 |
| NOT COMPLETED | 67 | 79 | 84 | 41 |
Reasons for not completing this period:
| Reason | V419 Lot A | V419 Lot B | V419 Lot C | Control |
|---|---|---|---|---|
| Withdrawal by Subject | 28 | 23 | 17 | 12 |
| Adverse Event | 1 | 0 | 1 | 0 |
| Lost to Follow-up | 29 | 48 | 53 | 23 |
| Physician Decision | 0 | 1 | 1 | 0 |
| Protocol Violation | 5 | 3 | 6 | 3 |
| Technical problems | 4 | 4 | 6 | 3 |
Period 3: Toddler Vaccinations
| Stage | V419 Lot A | V419 Lot B | V419 Lot C | Control |
|---|---|---|---|---|
| STARTED | 675 | 658 | 669 | 329 |
| COMPLETED | 666 | 641 | 660 | 319 |
| NOT COMPLETED | 9 | 17 | 9 | 10 |
Reasons for not completing this period:
| Reason | V419 Lot A | V419 Lot B | V419 Lot C | Control |
|---|---|---|---|---|
| Withdrawal by Subject | 2 | 2 | 1 | 1 |
| Lost to Follow-up | 6 | 14 | 7 | 8 |
| Protocol Violation | 0 | 0 | 0 | 1 |
| Technical problem | 1 | 1 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: The analysis population included participants who met the inclusion criteria, were not protocol violators, had an infant vaccination window of 42 to 84 days after the previous dose, and a blood draw sample window for the endpoint of 28 to 51 days after dose 3.
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 | V419 Lot A | V419 Lot B | V419 Lot C | Control | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 800 | 797 | 809 | 402 | 2808 | |
| Age, Continuous | Days | 64.6 (SD 6.7) | 64.4 (SD 6.2) | 64.7 (SD 6.6) | 64.3 (SD 6.6) | 64.5 (SD 6.5) |
| Sex: Female, Male: Female | Participants | 377 | 366 | 380 | 215 | 1338 |
| Sex: Female, Male: Male | Participants | 423 | 431 | 429 | 187 | 1470 |
6. Primary Endpoint
The registry lists the primary outcome as Geometric Mean Concentration of Antibodies to Polyribosylribitol Phosphate Antigen, measured over Postdose 3 (Month 7).
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | µg/mL |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was the geometric mean concentration of antibodies to polyribosylribitol phosphate, an antigen associated with the Haemophilus influenza type b capsular polysaccharide. Serum samples collected after dose 3 at Month 7 were tested using a radioimmunoassay. The result is expressed in µg/mL, with a 95% confidence interval.
A geometric mean summarizes measurements on a multiplicative scale. It is commonly used for antibody concentrations because immune measurements can vary over a wide range and may be skewed on the original scale. The geometric mean is obtained by working with logarithms of the measurements and then returning to the original scale. This summary describes the central concentration without implying that every participant had a value near that average.
For the lot comparisons, the registry reports ratios of geometric mean concentrations. A ratio near 1 indicates similar estimated concentrations on this scale; a ratio below or above 1 indicates that the numerator group’s estimated concentration was lower or higher than the denominator group’s, respectively. Confidence intervals convey uncertainty around the estimated ratio. A formal conclusion about equivalence or non-inferiority also depends on a prespecified margin and a defined decision rule. Those details are not reported in the registry record.
Antibody concentration is an immunogenicity measure. It describes an immune response measured in blood, rather than a clinical disease outcome. The registry record does not report a threshold linking the primary measurement to clinical protection.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary endpoint estimates were 5.51 µg/mL for V419 Lot A, 6.1 µg/mL for Lot B, and 6.59 µg/mL for Lot C. Their respective 95% confidence intervals were 4.88 to 6.21, 5.38 to 6.92, and 5.8 to 7.47. The combined V419-lot estimate was 6.05 µg/mL, with a 95% confidence interval of 5.63 to 6.5. The control estimate was 3.76 µg/mL, with a 95% confidence interval of 3.11 to 4.55. These are endpoint-specific estimates for the analysis population described in the registry, not estimates for every enrolled participant.
The registry-reported lot ratios were 0.91 for Lot A relative to Lot B, 0.86 for Lot A relative to Lot C, and 0.94 for Lot B relative to Lot C. Their 95% confidence intervals were 0.77 to 1.08, 0.72 to 1.02, and 0.79 to 1.12, respectively. Each interval includes 1, so the posted estimates do not distinguish the paired lot concentrations from equality at the level of these intervals. That observation is not equivalent to proving lot equivalence: equivalence depends on a prespecified acceptable range, which is not reported in the registry record.
For the combined V419 lots compared with control, the registry reports a geometric mean concentration ratio of 1.63, with a 95% confidence interval of 1.35 to 1.98 and p < 0.001. This is an ANCOVA analysis. It indicates that the estimated geometric mean concentration in the combined-lot group was higher than the control estimate in this analysis. The confidence interval gives a range of values compatible with the fitted analysis under its assumptions; it does not describe the range of individual participants’ antibody concentrations.
These results address antibody concentrations at the specified follow-up time. They do not establish clinical benefit, duration of response, or protection from infection. They also do not show whether the result applies to populations outside the healthy infants studied. The registry does not report the equivalence margin, the covariates used in the ANCOVA, or the full analysis plan. Those omissions limit how fully the lot-consistency and adjusted comparison procedures can be assessed from the record alone.
9. Statistical Methods Explained
The registry reports geometric mean concentrations and 95% confidence intervals for the primary endpoint, alongside ratios comparing groups. The combined-lot versus control analysis is identified as ANCOVA. General statistical concepts help clarify what these summaries mean, but the precise implementation details beyond those stated in the registry are not reported in the registry record.
What does a geometric mean describe?
Antibody concentration measurements are often analyzed on a logarithmic scale. On that scale, a multiplicative pattern in the original measurements becomes additive, which can make statistical modeling more appropriate. The geometric mean is calculated by averaging on the log scale and transforming the result back to the measurement scale. It therefore summarizes a typical concentration multiplicatively rather than as an ordinary arithmetic average. This is a general explanation; the registry identifies the endpoint as a geometric mean but does not describe every detail of the transformation or model used for each arm estimate.
How should a confidence interval be read?
A 95% confidence interval describes the statistical uncertainty around an estimate under the assumptions of the analysis. It is not a range containing 95% of individual participant measurements. A narrower interval generally represents greater precision than a wider interval, while the estimate remains subject to possible bias, measurement limitations, and analysis assumptions. For a ratio, a value of 1 represents equal estimated concentrations in the two groups being compared. The lot-ratio intervals include 1, while the combined-lot versus control interval lies above 1. The exact inferential meaning still depends on the analysis model and its assumptions.
Why use ratios for antibody concentrations?
Ratios are natural summaries when group measurements are considered on a multiplicative scale. A ratio below 1 means the numerator group’s estimated geometric mean is lower than the denominator group’s; a ratio above 1 means it is higher. Ratios can be easier to interpret than a subtraction when the outcome is analyzed logarithmically. They do not, on their own, define what difference is acceptable for equivalence or non-inferiority. Such a judgment requires a margin established before interpreting the data and a specified rule for comparing the confidence interval with that margin. The margin and rule are not reported in the registry record.
What does ANCOVA contribute?
Analysis of covariance, or ANCOVA, compares groups while adjusting for one or more covariates included in the model. In general, adjustment can account for measured differences or improve precision when covariates are appropriately chosen and modeled. The registry identifies ANCOVA for the combined-lot versus control ratio, but the covariates, model specification, and handling of assumptions are not reported in the registry record. The reported ratio and confidence interval should therefore be interpreted as results of the registry’s stated adjusted analysis, without inferring which variables were included.
What is the role of recalculated comparisons?
Simple unadjusted re-calculations from posted summary statistics can provide a separate descriptive comparison, but they do not necessarily reproduce the sponsor’s model. A recalculation based on group proportions, for example, uses a different estimand and approach from an ANCOVA of geometric mean concentrations. It cannot account for covariate adjustment or other analysis details that are absent from the summaries. Any such recalculation is supplementary and should not replace the registry-reported analysis.
How should planning illustrations be understood?
Sample-size illustrations based on an observed effect are planning exercises, not estimates of the trial’s achieved power. The stated assumptions for those illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For non-time-to-event outcomes, the displayed quantities represent participants per arm. Such estimates depend on the observed effect and the assumptions chosen, and can be unstable when the observed effect is small or imprecisely estimated. They do not reveal the trial’s original design calculation, which is not reported in the registry record.
Over-dispersion is a general issue for count or binary data when outcomes vary more than a basic statistical model expects. If it is ignored, estimated uncertainty can be too small. The primary endpoint is a concentration summarized geometrically, and the registry does not describe an over-dispersion analysis for it. The registered response outcomes are percentages, but their detailed model assumptions are not reported. It would therefore be inappropriate to assume a particular correction or modeling approach.
10. Analyses Reported by the Sponsor
| Method | Estimate | 95% CI | P-value |
|---|---|---|---|
| not stated | GMC Ratio (Lot A/Lot B) 0.91 | 0.77 to 1.08 | not reported |
| not stated | GMC Ratio (Lot A/Lot C) 0.86 | 0.72 to 1.02 | not reported |
| not stated | GMC Ratio (Lot B/Lot C) 0.94 | 0.79 to 1.12 | not reported |
| ANCOVA | GMC Ratio (Combined/Control) 1.63 | 1.35 to 1.98 | < 0.001 |
The registry-reported primary analyses are the main basis for interpreting this study’s stated endpoint. These include the lot-to-lot geometric mean concentration ratios and the ANCOVA ratio comparing combined V419 lots with control. The reported analyses do not include p-values for the lot-to-lot ratios; the registry gives their estimates and 95% confidence intervals. The combined-lot versus control analysis reports p < 0.001.
Some secondary outcomes also have simple unadjusted comparisons recalculated from posted summary statistics. Those results are not the same as the sponsor’s reported analyses, which include response-rate differences for selected lot comparisons. Differences in methods and estimands can yield different numerical results without either result being a transcription error. The registry does not flag a discrepancy between a sponsor analysis and a recalculation.
Accordingly, the sponsor’s reported analysis should be used to describe the trial’s own analysis, while recalculations can serve as an additional check or an illustrative analysis. A recalculation from aggregate counts does not reconstruct a model that used participant-level data, covariate adjustment, or other unreported choices. The statistical analysis plan and the details needed to reproduce those models are not reported in the registry record.
11. Multiplicity, Missing Data and Analysis Populations
The registry identifies a primary endpoint and lists 33 outcome measures and 112 analyses. It also reports multiple secondary response outcomes and several comparisons among vaccine lots and against control. This creates multiple opportunities for statistical findings. Whether and how the study controlled the overall false-positive risk across those analyses is not reported in the registry record. No conclusion about an adjustment method, testing hierarchy, or confirmatory status of secondary analyses can be drawn from the information recorded.
The primary analysis population is described with eligibility, protocol-violation, vaccination-window, and blood-draw-window criteria. The blood draw was required to fall 28 to 51 days after dose 3, and the vaccination window was 42 to 84 days after the previous dose. These restrictions define which participants contributed to the primary endpoint analysis. The registry does not describe how participants outside the analysis population were handled, how missing endpoint measurements were treated, or whether any imputation or sensitivity analysis was performed.
Arm counts differ across posted endpoints, and the record does not give a full explanation of each difference. This matters because an estimate based on participants with an observed endpoint may be affected if missingness is related to participant characteristics or outcomes. The record does not report whether missingness was assessed or whether the main analysis targeted all randomized participants, all vaccinated participants, or another analysis set beyond the stated primary population criteria.
The sample-size justification, interim analyses, detailed statistical analysis plan, and prespecified equivalence or non-inferiority margins are not reported in the registry record. These missing details limit assessment of whether the study was designed and analyzed to support formal lot-consistency conclusions. Their absence does not demonstrate that such procedures were not used; it means they cannot be evaluated from the registry record.
12. 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 |
|---|---|---|---|
| V419 Lots A, B, and C Combined | 94 | 2390 | 3.9% |
| Control | 15 | 397 | 3.8% |
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 |
|---|---|
| V419 Lots A, B, and C Combined | 2259 of 2390 |
| Control | 371 of 397 |
Most frequent serious adverse event terms
| Event term | Organ system | V419 Lots A, B, and C Combined | Control |
|---|---|---|---|
| Respiratory syncytial virus bronchiolitis | Infections and infestations | 12 of 2390 | 4 of 397 |
| Bronchiolitis | Infections and infestations | 9 of 2390 | 3 of 397 |
| Dehydration | Metabolism and nutrition disorders | 7 of 2390 | 1 of 397 |
| Pyrexia | General disorders | 4 of 2390 | 1 of 397 |
| Gastroenteritis | Infections and infestations | 5 of 2390 | 0 of 397 |
| Pneumonia | Infections and infestations | 5 of 2390 | 0 of 397 |
| Subcutaneous abscess | Infections and infestations | 4 of 2390 | 1 of 397 |
| Upper respiratory tract infection | Infections and infestations | 3 of 2390 | 1 of 397 |
| Skull fracture | Injury, poisoning and procedural complications | 3 of 2390 | 1 of 397 |
| Febrile convulsion | Nervous system disorders | 4 of 2390 | 0 of 397 |
Most frequent non-serious adverse event terms
| Event term | Organ system | V419 Lots A, B, and C Combined | Control |
|---|---|---|---|
| Irritability | General disorders | 1993 of 2390 | 324 of 397 |
| Injection-site pain | General disorders | 1883 of 2390 | 314 of 397 |
| Crying | General disorders | 1867 of 2390 | 300 of 397 |
| Somnolence | Nervous system disorders | 1816 of 2390 | 298 of 397 |
| Decreased appetite | Metabolism and nutrition disorders | 1355 of 2390 | 217 of 397 |
| Injection-site erythema | General disorders | 1302 of 2390 | 203 of 397 |
| Pyrexia | General disorders | 1285 of 2390 | 174 of 397 |
| Injection-site swelling | General disorders | 1073 of 2390 | 166 of 397 |
| Vomiting | Gastrointestinal disorders | 723 of 2390 | 110 of 397 |
| Upper respiratory tract infection | Infections and infestations | 276 of 2390 | 48 of 397 |
Serious events with the highest arm-level rate: respiratory syncytial virus bronchiolitis (1.0%), bronchiolitis (0.8%), viral upper respiratory tract infection (0.5%), dehydration (0.3%), lymphadenitis (0.3%).
For serious adverse events, the registry reports 94 affected participants among 2390 at risk in the combined V419-lot group and 15 among 397 at risk in control. These are participant counts and denominators, not a causal comparison. The record also reports other adverse events in 2259 of 2390 participants in the combined-lot group and 371 of 397 in control. These figures describe the groups as posted; they do not establish that an event was caused by a vaccine or that groups differed because of treatment.
The most frequently listed serious-event terms include respiratory syncytial virus bronchiolitis (1.0%), bronchiolitis (0.8%), viral upper respiratory tract infection (0.5%), dehydration (0.3%), lymphadenitis (0.3%), and pyrexia (0.3%). Event terms may describe related clinical concepts, and the registry record does not provide enough detail to assess overlap between terms or participant-level event histories. Death counts are not reported in the registry record.
Safety counts should be read alongside study population, follow-up, event definitions, and attribution procedures. Those details are not fully reported in the registry record. The figures therefore describe reported events during the recorded study, rather than proving a causal relationship or a difference in safety between groups.
13. What the Result Does, and Does Not, Mean
The posted primary results show measurable antibody concentrations to polyribosylribitol phosphate at Postdose 3 (Month 7) in all four groups. The estimated geometric mean concentrations differed across the three V419 lots, and the reported lot-to-lot ratio confidence intervals include 1. The combined-lot versus control analysis reports a ratio of 1.63 with a 95% confidence interval of 1.35 to 1.98 and p < 0.001. These estimates describe the registry’s antibody endpoint and its analysis population.
The evidence does not by itself establish that the V419 lots are formally equivalent. That conclusion requires the prespecified equivalence margin and decision criteria, which are not reported in the registry record. Nor does a higher estimated antibody concentration compared with control establish that the difference improves a clinical outcome. The primary endpoint is an immunogenicity measurement; the record does not state a protective threshold or report a clinical efficacy endpoint tied to it.
The results also do not answer how long the measured antibody response persists, whether responses predict protection, or whether the findings apply to infants outside the enrolled population. The posted estimates have confidence intervals and therefore statistical uncertainty, and they are subject to the eligibility and sampling criteria used for analysis. The number of participants included in each outcome differs.
More broadly, a completed randomized study with a posted primary result provides evidence about the measured comparisons under the study conditions. It does not resolve unreported protocol details, missing-data handling, multiplicity procedures, or safety attribution. Conclusions should remain specific to the outcomes, population, follow-up, and analyses documented in the registry.
14. Why This Trial Matters Statistically
This trial illustrates an important distinction in vaccine studies: comparing immune responses across manufacturing lots is not the same question as comparing a vaccine regimen with a control regimen. Lot-to-lot comparisons focus on consistency of the measured response. The combined-lot versus control comparison asks whether the estimated response differs between those groups. Each requires its own estimand, analysis, and interpretation.
The primary outcome also demonstrates why the scale of measurement matters. Antibody concentrations were summarized as geometric means, and group comparisons were expressed as ratios. These summaries match a multiplicative interpretation of concentration data. Reading them as though they were ordinary arithmetic differences would change the statistical question.
The registry’s lot-ratio estimates and confidence intervals show how interval precision and a formal decision margin both matter. Confidence intervals communicate uncertainty, but cannot replace a prespecified equivalence boundary. Without the margin, readers can see the estimated ratios and their uncertainty, but cannot determine whether the formal lot-consistency criterion was satisfied.
The broader set of outcomes also makes multiplicity relevant. Many antigens and comparisons can generate a large body of results, so the primary endpoint and analysis plan provide essential context for judging secondary findings. The registry record makes clear which endpoint is primary, but does not report the full testing hierarchy or adjustment strategy. This is a useful example of why statistical interpretation depends not only on estimates, but also on what was prespecified and how analyses were organized.
15. 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 does not report the prespecified margin or decision rule for assessing lot equivalence or non-inferiority. As a result, the posted lot ratios cannot be used alone to determine whether a formal consistency criterion was met. The record also does not provide the full statistical analysis plan, sample-size justification, interim-analysis information, or ANCOVA covariates.
The primary endpoint analysis was restricted by participant eligibility, protocol-violation status, vaccination timing, and blood-draw timing. These criteria are described, but the record does not explain how participants outside the population were handled or whether sensitivity analyses evaluated the effect of those exclusions. Missing-data methods are not reported. Outcome-specific sample sizes vary, and the reasons for every variation are not stated.
The registry lists many outcomes and analyses, but does not report whether multiplicity adjustments were applied or which secondary comparisons were intended to be confirmatory. This limits the weight that can be assigned to isolated secondary findings. The simple recalculations from summary statistics are unadjusted and cannot reproduce participant-level models or account for covariates.
The primary endpoint is an antibody concentration, not a clinical disease outcome. The record does not report a protective threshold or a clinical outcome that validates the concentration as a measure of protection. Safety figures are descriptive; the record does not establish event causation, and deaths are not reported. These limitations concern what can be concluded from the registry record, not evidence that unreported procedures or analyses were absent.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: A Study of V419 Given Concomitantly With Prevnar 13™ and RotaTeq™ (V419-006) — NCT01340937.
- Registry record last updated 2018-11-15; status last verified 2018-10.
- Results first posted 2016-05-02.
- 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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19. Record Summary
NCT01340937 is a completed randomized Phase III, parallel-group study of V419 in healthy infants. Enrollment was 2808. The official title describes a partially double-blind study, while the registry’s masking classification is quadruple.
The primary endpoint was geometric mean concentration of antibodies to polyribosylribitol phosphate after dose 3 at Month 7. The registry reports separate estimates for V419 Lot A, Lot B, Lot C, combined V419 lots, and control, as well as lot-to-lot ratios and a combined-lot versus control ANCOVA comparison. It also lists secondary antibody response outcomes and adverse-event counts.
The record does not report the full statistical analysis plan, sample-size justification, multiplicity procedure, missing-data approach, or equivalence margin. Interpretation is therefore most secure when limited to the posted estimates, confidence intervals, and stated analysis population.