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 on the Immune Response and Safety of a Combined Measles, Mumps, Rubella, Chickenpox Vaccine Compared to a Marketed Combined Vaccine, Given to Healthy Children 4 to 6 Years of Age (NCT05630846), a randomized phase 2 study. The primary outcome is GMC of Anti-measles Antibodies at Day 43.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05630846 |
| Phase | Phase 2 |
| Condition | Measles; Mumps; Rubella; Chickenpox, Measles |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 801 |
| Arms in the primary outcome | 4 |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled healthy children 4 to 6 years of age. The registry reports enrollment of 801. The primary endpoint analysis used a per-protocol population: eligible participants who received study intervention as specified, were not unblinded, had the required immunogenicity measurements and blood-draw timing, and met the other stated analysis criteria. Only participants with data at the specified timepoint were included.
Intervention
Participants received a single dose on Day 1 of one of three investigational formulations. The formulations varied in whether measles, mumps, rubella, or varicella components were at release, high, or low potency. The registry describes the groups as MMRV(H)NS, MM(H)RVNS, and M(L)M(L)R(L)V(L)NS.
Comparator
The comparator group received a single dose of a marketed MMRV vaccine, with participants assigned to Lot 1 or Lot 2. The registry names ProQuad in the official study title and describes the marketed vaccine as the comparator. The reported primary outcome results include a pooled Lot 1 and Lot 2 group.
Primary question
The principal question was how the groups’ anti-measles antibody geometric mean concentrations compared at Day 43. The registry also lists seroresponse for measles, mumps, rubella, and varicella, along with adverse-event outcomes. The primary results give group estimates and confidence intervals, but a formal between-group primary-endpoint analysis is not reported in the registry record.
3. Trial Design
This is a Phase II randomized, controlled study with a parallel-group structure. The registry reports enrollment of 801 and a completed study. Its stated start date is 2022-12-14 and its primary completion date is 2024-06-07. The study population was healthy children 4 to 6 years of age.
The four groups received a single vaccine dose on Day 1. Three groups received investigational formulations with different potency descriptions: one had measles, mumps, and rubella at release potency and varicella at high potency; another had mumps at high potency with the other stated components at release potency; and the third had all listed components at low potency. The remaining group received the marketed vaccine, using Lot 1 or Lot 2. The registry reports pooled results for those marketed lots for the primary endpoint.
There is a discrepancy in the masking descriptions: the structured registry record says double masking, while the official title calls the study single-blind. The exact masking procedures and which parties were masked are not reported in the registry record. The allocation is described as randomized, but the randomization sequence method and allocation-concealment details are not reported in the registry record.
The primary endpoint was assessed at Day 43. The registry’s endpoint description says the anti-measles antibodies were measured using a multiplex luminex-based immunoassay and expressed as geometric mean concentrations in mIU/mL. The primary analysis population was per protocol, with eligibility and measurement requirements described in the endpoint record. The registry lists 13 outcome measures; the sample-size justification, detailed protocol, and 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 participants enrolled in the measles, mumps, rubella, and varicella vaccine (investigational vaccine) (MMRVNS) groups were randomized to 3 formulations which varied in some or all the individual viral potencies. Participants enrolled in the measles, mumps, rubella, and varicella vaccine (comparator vaccine) (MMRV) group were randomized to 2 different lots. Throughout the study, the 2 lots were analyzed as a pooled group.
Overall Study
| Stage | MMRV(H)NS Vaccine | MM(H)RVNS Vaccine | (MMRV)(L)NS Vaccine | MMRV_Lot 1 and Lot 2 Pooled Group |
|---|---|---|---|---|
| STARTED | 198 | 200 | 203 | 195 |
| COMPLETED | 187 | 192 | 197 | 189 |
| NOT COMPLETED | 11 | 8 | 6 | 6 |
Reasons for not completing this period:
| Reason | MMRV(H)NS Vaccine | MM(H)RVNS Vaccine | (MMRV)(L)NS Vaccine | MMRV_Lot 1 and Lot 2 Pooled Group |
|---|---|---|---|---|
| Death | 1 | 0 | 0 | 0 |
| Withdrawal by Subject | 3 | 3 | 4 | 1 |
| Lost to Follow-up | 6 | 5 | 2 | 5 |
| Other | 1 | 0 | 0 | 0 |
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 | MMRV(H)NS Vaccine | MM(H)RVNS Vaccine | (MMRV)(L)NS Vaccine | MMRV_Lot 1 and Lot 2 Pooled Group | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 198 | 200 | 203 | 195 | 796 | |
| Age, Continuous | years | 4.2 (SD 0.4) | 4.2 (SD 0.5) | 4.2 (SD 0.5) | 4.2 (SD 0.5) | 4.2 (SD 0.5) |
| Sex: Female, Male: Female | Participants | 73 | 85 | 105 | 99 | 362 |
| Sex: Female, Male: Male | Participants | 125 | 115 | 98 | 96 | 434 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 34 | 33 | 33 | 33 | 133 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 25 | 36 | 33 | 37 | 131 |
| Race (NIH/OMB): White | Participants | 123 | 113 | 115 | 109 | 460 |
| Race (NIH/OMB): More than one race | Participants | 15 | 17 | 19 | 15 | 66 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 | 1 | 3 | 1 | 6 |
6. Primary Endpoint
The registry lists the primary outcome as GMC of Anti-measles Antibodies at Day 43, measured over At Day 43.
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | mIU/mL |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the geometric mean concentration (GMC) of anti-measles antibodies at Day 43, measured in mIU/mL. It summarizes antibody concentrations for each analyzed group as a geometric mean rather than as a proportion of participants who crossed a response threshold. The registry states that antibody concentrations were measured with a multiplex luminex-based immunoassay.
As a general statistical explanation, a geometric mean is calculated on a logarithmic scale and then expressed back on the original scale. It is often used for measurements that are positive and may be unevenly distributed, such as antibody concentrations. It provides a group-level summary of typical concentration without treating large values as though their effects on the summary should be additive on the original scale.
The endpoint is used to describe the antibody concentration reached after vaccination, while the listed seroresponse outcomes describe the percentage meeting a response definition. Those are different summaries and answer different questions. The response definition itself is not reported in the registry record. The posted primary results give a GMC and a 95% confidence interval for each group. A formal comparative estimate or reported statistical test for the primary endpoint is not reported in the registry record, so the group estimates alone do not establish the result of a planned between-group hypothesis test.
The primary analysis was restricted to the per-protocol set described in the record. That set required study intervention and adherence to specified immunogenicity and blood-draw conditions, as well as the absence of certain interfering medical conditions and prohibited concomitant medication or vaccination. Only participants with data at the specified timepoint were analyzed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary results show anti-measles antibody GMCs at Day 43 of 801 mIU/mL for the MMRV(H)NS group, 788 mIU/mL for the MM(H)RVNS group, 728 mIU/mL for the low-potency group, and 682 mIU/mL for the pooled marketed-vaccine group. The corresponding 95% confidence intervals are 691 to 928, 682 to 910, 622 to 852, and 581 to 801 mIU/mL. These are group-level estimates from the per-protocol analysis.
The intervals overlap. As a general statistical point, confidence intervals describe uncertainty around an estimate under the assumptions of the analysis; overlap is not itself a formal test of whether two groups differ. The registry record does not report a primary-endpoint comparison, a comparative confidence interval, or a primary-endpoint p-value. Therefore, the posted group summaries do not establish whether any investigational group differed statistically from the marketed-vaccine group on the primary endpoint.
The secondary results include seroresponse outcomes and unsolicited adverse events. Some simple, unadjusted comparisons have also been recalculated from the posted summaries. For measles seroresponse, the recalculated unadjusted p-values are 0.326 for the MM(H)RVNS comparison and 0.051 for the low-potency comparison. For mumps seroresponse, the corresponding values are 0.151 and 0.162. For unsolicited adverse events, they are 0.356 and 0.735. These are not reported sponsor analyses; they are unadjusted recalculations from summary statistics. The registry record contains no reported analyses for these outcomes.
The recalculated comparisons should be read cautiously. They are unadjusted, and the registry record does not report a multiplicity procedure or an inferential analysis plan for these comparisons. A p-value does not quantify the probability that a treatment effect is real, and it does not show whether a difference is important. Confidence intervals for the recalculated risk differences are also available for the comparisons; they are broad in several instances and include values compatible with little or no difference. The recalculated results cannot replace a sponsor’s prespecified analysis. The discrepancy indicator is false, but reported sponsor analyses are still not available in the registry record.
Planning figures based on observed effects are illustrations for future study planning, not evidence of the power of this completed trial. They depend on the stated assumptions and on an effect size derived from the observed data. They should not be interpreted as observed power or as proof that a comparison was adequately powered. The registry’s own sample-size rationale and design assumptions are not reported in the registry record.
9. Statistical Methods Explained
The results involve several statistical ideas that are useful to distinguish. The primary endpoint is a continuous antibody-concentration summary, while the secondary seroresponse and adverse-event outcomes are proportions or participant counts. A GMC and a percentage with seroresponse do not measure the same feature of the immune response. Similarly, the number of participants with an adverse event is not a measure of antibody concentration.
What does a confidence interval express?
As a general explanation, a confidence interval gives a range of values compatible with an estimate under the statistical method used. A narrower interval indicates greater precision under that method; a wider interval indicates more uncertainty. The primary results report 95% confidence intervals for each group’s GMC. These intervals describe uncertainty around the individual group estimates, not around a comparison between groups. The registry record does not report a primary comparative interval, so one should not treat the group intervals as a substitute for it.
For the posted percentage outcomes, the intervals accompany the estimated seroresponse percentages. For recalculated comparisons, the intervals describe the risk difference: the difference between the two group proportions, expressed on the proportion scale. In general, a risk difference near zero is compatible with little difference on that scale. An interval spanning zero includes values on both sides of no difference, so it does not establish a direction of difference at the interval’s confidence level. These recalculated intervals are not sponsor-reported analyses.
What does an unadjusted p-value mean?
As a general explanation, a p-value measures how incompatible the observed data are with a specified null model, assuming that model and the analysis assumptions are correct. It is not the probability that the null hypothesis is true, and it does not measure clinical importance. The p-values shown for selected secondary comparisons are unadjusted recalculations from posted group summaries. They should not be interpreted as confirmatory results because no sponsor-reported analysis is listed for these comparisons and no multiplicity adjustment is reported.
Multiple endpoints and multiple group comparisons create opportunities for chance findings. As a general statistical principle, testing many questions without accounting for multiplicity increases the chance that at least one result appears notable by chance. The registry record lists 13 outcome measures, but a method for controlling family-wise error or otherwise handling multiple comparisons is not reported in the registry record. The posted secondary comparisons therefore have a more exploratory interpretation unless a prespecified analysis plan establishes otherwise.
Why use a geometric mean?
As a general explanation, antibody measurements are positive concentrations, and their distributions may be skewed. The geometric mean summarizes them by averaging on a logarithmic scale and transforming back. This can make the group summary less dominated by very high concentrations than an arithmetic mean would be. The registry reports GMCs and 95% confidence intervals, but the precise method used to construct those intervals is not reported in the registry record.
The use of a GMC does not imply that every participant had a value close to the group estimate. Individual-level distributions, quantiles, and the spread of individual antibody concentrations are not reported in the registry record. The GMC is an aggregate summary, not a description of every participant’s response.
How should the per-protocol analysis be read?
The primary endpoint analysis used a per-protocol set. The registry defines it as eligible participants who received intervention as specified, were not unblinded, had immunogenicity results before and after dosing for at least one antigen, met the specified blood-draw interval, had no stated interfering medical condition, and did not receive prohibited concomitant medication or vaccination. Only those with data at the stated timepoint were analyzed.
As a general explanation, a per-protocol analysis focuses on participants meeting specified study requirements. It can describe outcomes among those who adhered to the protocol, but it may be less representative of all randomized participants if exclusions are related to outcomes or treatment assignment. The registry record does not report the numbers excluded from the primary analysis, reasons by group, or a complementary intention-to-treat analysis. The effect of those exclusions therefore cannot be assessed from the posted information.
What are the planning illustrations?
The sample-size illustrations use observed effects as a starting point and consider detecting specified fractions of those effects. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. As a general statistical explanation, such calculations estimate the number of participants per arm that a hypothetical future study might require under those assumptions and effect-size choices.
These figures are planning illustrations, not the observed power of this study. Because the effect used is estimated from the observed results, it is uncertain and may not represent the effect a future study should target. The illustrations also depend on assumptions such as equal allocation and the selected model. The sample-size justification used when designing this trial, and whether its actual design used these assumptions, are not reported in the registry record. The registry’s analysis plan and any interim-analysis procedures are also not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 13 outcome measures and indicates that nine secondary outcomes are posted. Several kinds of outcomes are represented: antibody GMC, antigen-specific seroresponse, and participant counts for adverse events. Considering multiple outcomes or comparing several groups raises multiplicity concerns. As a general statistical explanation, when many statistical questions are tested, some may appear unusual by chance even when there is no underlying difference. A prespecified hierarchy, adjustment procedure, or distinction between confirmatory and exploratory outcomes can help readers interpret such results.
Those details are not reported in the registry record. In particular, the record does not state a multiplicity adjustment, a hierarchy among secondary outcomes, or which comparisons were intended to be confirmatory. The registry reports no analyses for the primary comparison, and the secondary records list no reported analyses. The p-values and comparison estimates discussed for selected secondary outcomes are unadjusted recalculations from posted summary data. They should not be treated as if they came from a reported prespecified testing plan.
The primary analysis population is described as per protocol, with requirements covering intervention, blinding status, immunogenicity measurements, sample timing, interfering conditions, and prohibited concomitant medication or vaccination. Only participants with data at the specified timepoint were included. The registry record does not give the number excluded from this analysis, missing-data rates by group, or reasons for missing measurements. It also does not report an imputation method, sensitivity analysis, or a parallel intention-to-treat result for the primary endpoint.
The analysis population and handling of missing data for the secondary outcomes are not reported in the registry record. Without those details, it is not possible to assess whether participants contributing to different endpoints were comparable or whether missingness could have affected estimates. As a general principle, complete-case results can be biased when the availability of measurements is related to the outcome or group assignment. The posted summaries alone do not show whether that concern applies in this study.
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 |
|---|---|---|---|
| MMRV(H)NS Vaccine | 1 | 198 | 0.5% |
| MM(H)RVNS Vaccine | 1 | 200 | 0.5% |
| (MMRV)(L)NS Vaccine | 1 | 203 | 0.5% |
| MMRV_Lot 1 and Lot 2 Pooled Group | 1 | 195 | 0.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| MMRV(H)NS Vaccine | 1 of 198 |
| MM(H)RVNS Vaccine | 0 of 200 |
| (MMRV)(L)NS Vaccine | 0 of 203 |
| MMRV_Lot 1 and Lot 2 Pooled Group | 0 of 195 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| MMRV(H)NS Vaccine | 127 of 198 |
| MM(H)RVNS Vaccine | 114 of 200 |
| (MMRV)(L)NS Vaccine | 126 of 203 |
| MMRV_Lot 1 and Lot 2 Pooled Group | 132 of 195 |
Most frequent serious adverse event terms
| Event term | Organ system | MMRV(H)NS Vaccine | MM(H)RVNS Vaccine | (MMRV)(L)NS Vaccine | MMRV_Lot 1 and Lot 2 Pooled Group |
|---|---|---|---|---|---|
| Pneumonia | Infections and infestations | 0 of 198 | 1 of 200 | 1 of 203 | 0 of 195 |
| Gastroenteritis | Infections and infestations | 0 of 198 | 0 of 200 | 0 of 203 | 1 of 195 |
| Homicide | Social circumstances | 1 of 198 | 0 of 200 | 0 of 203 | 0 of 195 |
Most frequent non-serious adverse event terms
| Event term | Organ system | MMRV(H)NS Vaccine | MM(H)RVNS Vaccine | (MMRV)(L)NS Vaccine | MMRV_Lot 1 and Lot 2 Pooled Group |
|---|---|---|---|---|---|
| Administration site pain | General disorders | 76 of 198 | 58 of 200 | 64 of 203 | 76 of 195 |
| Administration site erythema | General disorders | 41 of 198 | 34 of 200 | 26 of 203 | 42 of 195 |
| Somnolence | Nervous system disorders | 27 of 198 | 18 of 200 | 32 of 203 | 32 of 195 |
| Pyrexia | General disorders | 27 of 198 | 25 of 200 | 25 of 203 | 27 of 195 |
| Rashes, eruptions and exanthems NEC | Skin and subcutaneous tissue disorders | 24 of 198 | 23 of 200 | 27 of 203 | 17 of 195 |
| Decreased appetite | Metabolism and nutrition disorders | 20 of 198 | 14 of 200 | 22 of 203 | 26 of 195 |
| Administration site swelling | General disorders | 24 of 198 | 21 of 200 | 14 of 203 | 20 of 195 |
| Upper respiratory tract infection | Infections and infestations | 9 of 198 | 7 of 200 | 7 of 203 | 10 of 195 |
| Nasopharyngitis | Infections and infestations | 2 of 198 | 2 of 200 | 5 of 203 | 5 of 195 |
| Injection site pain | General disorders | 2 of 198 | 4 of 200 | 4 of 203 | 3 of 195 |
Serious events with the highest arm-level rate: gastroenteritis (0.5%), homicide (0.5%), pneumonia (0.5%).
The serious adverse-event summary lists one affected participant in each of the four groups, with the at-risk counts reported as 198, 200, 203, and 195, respectively. The listed serious-event terms are Gastroenteritis, Homicide, and Pneumonia, each reported at 0.5%. The registry also records one death in the MMRV(H)NS group and zero deaths in each of the other groups. The record does not state whether the death was related to vaccination, nor does it provide a causal assessment for the serious events.
These figures should be read as counts and listed event terms, not as evidence that an event was caused by a vaccine. The registry record does not provide enough detail to establish timing, clinical course, investigator attribution, or whether a listed term occurred in a particular group. Rare serious events are difficult to compare reliably across groups in a study of this size, and a small or absent count does not rule out risk.
The other posted safety information includes unsolicited adverse-event participant counts during Day 1 to Day 43. Solicited adverse events are listed among the outcomes, but their results are not detailed in the endpoint records. The registry’s group counts should not be combined across event categories or interpreted as a complete safety profile. No medical conclusion about an individual participant or vaccine should be drawn from these aggregate registry summaries.
12. What the Result Does, and Does Not, Mean
The results establish that the registry reports Day 43 anti-measles antibody GMC estimates and 95% confidence intervals for each of the listed groups. They also show posted group-level seroresponse results for selected antigens and participant counts for unsolicited adverse events. These are descriptive findings from the recorded analysis populations and follow-up periods.
They do not, on their own, establish that an investigational formulation is superior, equivalent, or non-inferior to the marketed vaccine. The primary endpoint record does not include a reported formal comparison, comparative confidence interval, or p-value. The fact that individual group confidence intervals overlap is not a substitute for a direct comparison. The secondary comparisons available in the record are unadjusted recalculations, not sponsor-reported tests, and the record does not state how multiplicity was handled.
The primary GMC should not be interpreted as the response of every child. It is a group summary, and the registry record does not provide individual antibody measurements or their full distribution. Likewise, seroresponse percentages represent a different endpoint from GMC, and the response criterion is not reported. The posted summaries cannot resolve how well an individual child will respond or predict an individual safety outcome.
The per-protocol analysis applies to participants who met specified study and measurement requirements. The registry does not report exclusions, missingness by group, or an intention-to-treat analysis, so the impact of these choices cannot be assessed. Safety counts provide a record of events observed in the study groups, but they do not establish causation and do not rule out uncommon events.
As a general statistical point, a registry result is best interpreted in light of the full protocol and prespecified statistical analysis plan. Those documents and the sponsor’s detailed inferential analyses are not reported in the registry record. The findings therefore describe the posted data without supporting a broader treatment recommendation or definitive comparative claim.
13. Why This Trial Matters Statistically
This study raises statistical issues common to vaccine trials: several formulations, multiple antigens, antibody outcomes measured on different scales, and safety outcomes observed over defined periods. A single headline comparison cannot capture all these questions. The distinction between GMC and seroresponse is especially important because concentration summaries and response-threshold percentages can show different aspects of immunogenicity.
The registry reports four group GMC estimates, but not a formal primary comparison. This makes it important to separate descriptive estimates from inferential conclusions. Confidence intervals quantify uncertainty around each group estimate; they do not automatically answer whether groups differ. A direct comparison, with its own estimate and uncertainty, would be needed to assess that question under a defined analysis plan.
The study also illustrates why multiplicity and analysis populations matter. The outcome list spans multiple antigens and safety categories, while the primary analysis uses a per-protocol set. Without a reported testing hierarchy, multiplicity approach, missing-data assessment, and complementary analysis population, readers cannot determine how confirmatory the secondary patterns are or how sensitive the primary summary may be to exclusions.
Finally, planning calculations based on observed effects should not be confused with trial power. They are hypothetical illustrations for future designs, relying on assumptions and estimated effects. The trial’s own sample-size justification is not reported in the registry record. Clear distinctions among observed summaries, recalculated comparisons, and planning illustrations help keep the statistical interpretation aligned with what the record actually documents.
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.
Several limitations specific to this trial affect interpretation. First, the primary endpoint is reported as group-level GMCs with confidence intervals, but a formal between-group analysis is not reported in the registry record. A reader can describe the estimates but cannot use the registry summary alone to establish the planned comparative result.
Second, the registry descriptions of masking differ: the structured record says double masking, while the official title says single-blind. The procedures and roles masked are not reported in the registry record. This discrepancy leaves uncertainty about the masking arrangement as implemented.
Third, the primary endpoint analysis is per protocol and includes only participants with data at the specified timepoint. The registry record does not report group-specific analysis exclusions, missing data, reasons for missingness, or a complementary intention-to-treat estimate. The possible effect of these features on the reported GMCs cannot be assessed.
Fourth, several outcome details needed for interpretation are absent. The seroresponse definition, analysis method for the GMC intervals, analysis populations for secondary outcomes, and sponsor-reported tests are not reported in the registry record. The record also does not describe adjustment for multiple endpoints or group comparisons. Selected secondary comparisons are unadjusted recalculations, so their inferential role is limited.
Finally, serious adverse-event counts are sparse and aggregate. The registry does not report causal attribution for the events or death, nor enough event-level information to compare their circumstances across groups. The data therefore document events recorded in the trial, but do not establish causation or provide a complete assessment of uncommon safety outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study on the Immune Response and Safety of a Combined Measles, Mumps, Rubella, Chickenpox Vaccine Compared to a Marketed Combined Vaccine, Given to Healthy Children 4 to 6 Years of Age — NCT05630846.
- Registry record last updated 2025-06-22; status last verified 2025-06.
- Results first posted 2025-06-22.
- 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
The registry record describes a completed randomized, controlled Phase II parallel-group study of vaccine immune response and safety in healthy children 4 to 6 years of age. Enrollment is reported as 801. Participants received a single Day 1 dose of one of three investigational formulations or a marketed MMRV vaccine from Lot 1 or Lot 2.
The primary outcome is anti-measles antibody GMC at Day 43, measured in mIU/mL. Results are reported for a per-protocol analysis, with group estimates and 95% confidence intervals. A formal primary comparison is not reported in the registry record. Listed secondary outcomes include antigen-specific seroresponse and adverse events; selected secondary summaries and unadjusted recalculations are available, but sponsor-reported analyses are not listed. The record also includes serious adverse-event counts and death counts, without reported causal attribution.
Important details—including the sample-size justification, multiplicity strategy, missing-data assessment, and full statistical analysis plan—are not reported in the registry record. The masking description also differs between the structured record and official title.