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 Clinical Study of the V116 Vaccine for Children and Teenagers (V116-013) (NCT06177912), a randomized phase 3 study. The primary outcome is Percentage of Participants With Solicited Injection-site Adverse Events (AEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT06177912 |
| Phase | Phase 3 |
| Condition | Pneumococcal Infection |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 882 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Merck Sharp & Dohme LLC |
| Results posted | Yes |
2. Clinical Question
Population
Children and adolescents 2 through 17 years of age who had completed routine pneumococcal vaccination as infants or toddlers and were considered at increased risk of pneumococcal disease. The primary analysis population is described as participants who received study vaccination and had documented initial consent. The registry record does not report further eligibility details or the distribution of participants across age or risk categories.
Intervention
V116, given as a single 0.5 mL intramuscular injection on Day 1. The study evaluates safety, tolerability, and immunogenicity. Immunogenicity outcomes include antibody measures specific to pneumococcal serotypes.
Comparator
PPSV23, given as a single 0.5 mL intramuscular dose on Day 1. The registry describes this as the comparator for evaluating V116, including the antibody immune response. It does not report a primary immunogenicity endpoint in the registry record for this analysis.
Primary question
The listed primary outcome is the percentage of participants with solicited injection-site adverse events up to 5 days after vaccination. Solicited events include pain or tenderness, redness or erythema, and swelling. The registry record does not provide a single reduced comparison for this endpoint or report its result, so the primary safety comparison cannot be quantified from the listed details.
3. Trial Design
This is a Phase 3, randomized, double-blind study with a parallel-group design. The registry lists triple masking, meaning masking is recorded at three levels, but it does not identify those roles in the registry record. Participants were assigned to V116 or PPSV23. Each arm description specifies one intramuscular dose on Day 1: 0.5 mL of V116 or 0.5 mL of PPSV23.
The study focuses on children and adolescents aged 2 through 17 years who had completed routine pneumococcal vaccination as infants or toddlers and were at increased risk of pneumococcal disease. The registry lists pneumococcal infection as the condition. Its stated purpose is to evaluate safety, tolerability, and immunogenicity, including whether the antibody response with V116 is as good as or better than the response with PPSV23. That purpose is not itself a reported finding.
Enrollment is listed as 882. The study began on 2024-01-18, reached primary completion on 2025-02-26, and is recorded as completed. The registry record does not report the number assigned to each arm in the registry record for this analysis, nor does it explain whether enrollment refers to participants screened, randomized, or otherwise enrolled. It also does not report a statistical analysis plan, the randomization method, allocation concealment procedures, or the identities of the masked groups.
The listed secondary outcomes include serotype-specific IgG geometric mean concentrations, geometric mean fold rises in opsonophagocytic assay geometric mean titers, and the percentages of participants with at least a four-fold rise in those antibody measures. These describe immune responses, distinct from the primary injection-site safety outcome. The registry lists nine outcome measures and 55 analyses, but the primary endpoint information is not reduced to one comparison 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: Children and adolescents between 2 and 18 years of age with an increased risk of pneumococcal disease were enrolled in this study.
Overall Study
| Stage | V116 | PPSV23 |
|---|---|---|
| STARTED | 531 | 351 |
| Vaccinated | 528 | 348 |
| Safety Analysis Population | 527 | 347 |
| COMPLETED | 522 | 345 |
| NOT COMPLETED | 9 | 6 |
Reasons for not completing this period:
| Reason | V116 | PPSV23 |
|---|---|---|
| Death | 0 | 2 |
| Lost to Follow-up | 2 | 0 |
| Randomized By Mistake Without Study Treatment | 1 | 1 |
| Withdrawal By Parent/Guardian | 5 | 3 |
| Randomized By Mistake With Study Treatment | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: The analysis population consisted of all participants who received study vaccination and had documented initial consent.
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 | V116 | PPSV23 | Total |
|---|---|---|---|---|
| Participants analysed | 531 | 351 | 882 | |
| Age, Continuous | Years | 8.2 (SD 4.1) | 7.8 (SD 3.8) | 8.0 (SD 4.0) |
| Sex: Female, Male: Female | Participants | 220 | 142 | 362 |
| Sex: Female, Male: Male | Participants | 311 | 209 | 520 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 233 | 158 | 391 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 298 | 192 | 490 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 48 | 43 | 91 |
| Race (NIH/OMB): Asian | Participants | 48 | 37 | 85 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 31 | 20 | 51 |
| Race (NIH/OMB): White | Participants | 322 | 203 | 525 |
| Race (NIH/OMB): More than one race | Participants | 82 | 48 | 130 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With Solicited Injection-site Adverse Events (AEs), measured over Up to 5 days postvaccination.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants with solicited injection-site adverse events up to 5 days after vaccination. Solicited events are specifically identified as pain or tenderness, redness or erythema, and swelling. An adverse event is defined in the registry as an untoward medical occurrence temporally associated with study intervention, whether or not it is considered related to that intervention. The endpoint’s analysis population consists of participants who received study vaccination and had documented initial consent.
A percentage endpoint describes how often an event is recorded among participants in a defined analysis population. In this case, the focus is on injection-site symptoms reported within a specified period after vaccination. Such an outcome is used to characterize short-term local tolerability; it is not an antibody measure or a direct measure of protection against pneumococcal disease.
The registry record does not report separate values for pain or tenderness, redness or erythema, and swelling, nor does it state whether the overall endpoint counts participants with any listed event or presents each event category separately. The record flags that the primary outcome has several categories or time points and is not reduced to one comparison. Therefore, the endpoint’s definition is available, but a single numerical comparison between the vaccine groups is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The trial record establishes the setting for interpreting the comparison: a randomized, double-blind, parallel-group Phase 3 study of V116 versus PPSV23 in children and adolescents at increased risk of pneumococcal disease. The primary endpoint concerns solicited injection-site adverse events up to 5 days after vaccination. However, no single primary comparison or result is reported in the registry record. Without an endpoint estimate and its uncertainty, the direction, size, and precision of a primary difference cannot be assessed from these registry entries.
The record does list adverse-event counts by arm. For serious adverse events, it lists 29 affected among 527 at risk in the V116 group and 25 among 347 at risk in the PPSV23 group. For other adverse events, it lists 408 among 527 at risk with V116 and 237 among 347 at risk with PPSV23. These are descriptive registry figures. The record does not provide confidence intervals, a comparative effect estimate, or a statistical test for these counts in the registry record for this analysis. The counts alone do not establish whether an observed difference is compatible with chance or is clinically important.
Deaths are listed as 0 in the V116 group and 2 in the PPSV23 group. The record does not provide details about the circumstances, timing, causes, or relationship of these deaths to vaccination. Those details are not reported in the registry record, so the counts should not be interpreted as evidence of causation.
The registry also lists serious adverse-event terms with percentages: urinary tract infection and asthma at 0.8% each; anaphylactic reaction, respiratory tract infection viral, pneumonia, and diabetic ketoacidosis at 0.6% each. The record does not identify the denominator or arm for these listed percentages in the registry record for this analysis, so they cannot be used to make an arm-to-arm comparison.
Secondary outcome descriptions cover antibody concentrations and rises in serotype-specific immune measures. These outcomes are relevant to immunogenicity, but their names are not their results. The registry record does not report the values, uncertainty intervals, or comparative findings for these outcomes in the registry record. Accordingly, the stated aim of comparing antibody responses should be distinguished from evidence of any particular response.
Overall, the available record supports a description of the design, endpoint definitions, and listed safety counts, but not a conclusion about the primary endpoint or the comparative immunogenicity of the study vaccines. Statistical significance, precision, and the clinical importance of comparative effects are not reported in the registry record.
9. Statistical Methods Explained
The design determines what kinds of comparisons the study can support. Random assignment is intended, in general, to make treatment groups comparable with respect to both measured and unmeasured characteristics at the time of assignment. A parallel-group design means participants are assigned to one study group rather than receiving both interventions in sequence. Double-blind describes masking in the study, while the registry records triple masking. The specific people or roles masked are not reported in the registry record. These design features do not by themselves guarantee that every analysis is unbiased; the analysis population, outcome definition, missing data, and conduct of the study also matter.
What does the primary percentage represent?
The primary outcome is a percentage of participants with solicited injection-site adverse events during the period up to 5 days postvaccination. In general, a percentage summarizes the frequency of an event within a specified group and analysis population. It depends on a clear numerator definition, a denominator definition, and a defined observation period. Here, the registry gives the primary analysis population and names pain or tenderness, redness or erythema, and swelling as solicited injection-site events. It does not report a single reduced endpoint comparison or the specific component-level results. Thus, the endpoint definition should not be mistaken for an observed estimate.
The primary outcome parameter is recorded as NUMBER, with the unit described as percentage of participants and the outcome kind described as a percentage of participants with an event. The registry record does not provide a comparative estimate, a confidence interval, or a p-value for this primary outcome in the registry record for this analysis. The labels used to describe an endpoint do not substitute for those results.
How should uncertainty be understood?
In general, a confidence interval expresses the range of estimates reasonably compatible with the observed data under the assumptions of the analysis. It conveys precision as well as direction and magnitude. A narrow interval indicates greater precision than a wide interval, while an interval spanning a range of effects may leave substantial uncertainty. A p-value, in general, describes how surprising data at least as incompatible with a specified null hypothesis would be under that hypothesis and the statistical model. It does not measure the probability that the null hypothesis is true, nor does it measure clinical importance.
No confidence interval or p-value for the primary comparison is reported in the registry record. It is therefore not possible to assess the primary estimate’s precision or statistical compatibility with a null effect from the listed details. The same caution applies to the listed adverse-event counts: counts alone do not quantify uncertainty in a group contrast.
What do the safety counts show?
The registry lists serious adverse events and other adverse events separately for the two groups. The serious-event figures are 29 affected among 527 at risk for V116 and 25 among 347 at risk for PPSV23. The other-event figures are 408 among 527 at risk for V116 and 237 among 347 at risk for PPSV23. These are descriptive counts and denominators, not adjusted comparisons. In general, a comparison of event proportions should specify the event definition, analysis population, observation period, and method for estimating uncertainty. The registry record does not report a comparative effect estimate or inferential method for these figures in the registry record for this analysis.
There are 0 deaths listed in the V116 group and 2 in the PPSV23 group. General statistical interpretation of sparse outcomes requires particular caution: a small count may yield considerable uncertainty, and a count alone gives no information about cause or attribution. Circumstances and relatedness are not reported in the registry record.
What can be said about the planned analyses?
The registry lists nine outcome measures and 55 analyses. This indicates that multiple outcome analyses are recorded, but does not explain their hierarchy, which comparisons were prespecified, or how multiplicity was handled. The statistical plan and any interim analyses are not reported in the registry record. No assumption about adjustment for multiple testing, model selection, or analysis timing can be made from the available details.
The record includes a general description of sample-size planning illustrations: a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of the observed effect. For time-to-event tables, the stated illustration would concern total events; for other outcomes, it would concern participants per arm. These are descriptions of planning assumptions, not observed power and not evidence of the trial’s own design calculations. The registry record does not report planning counts or a sample-size justification in the registry record for this analysis. Such illustrations, when available, are hypothetical planning aids and cannot replace an analysis of the trial results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists nine outcome measures and 55 analyses, including multiple serotype-specific immunogenicity measures and several ways of describing antibody response. When many outcomes or comparisons are examined, the chance of at least one apparently unusual result can increase. In general, a statistical analysis plan can specify which outcomes are primary, how secondary outcomes are interpreted, and whether any adjustment or hierarchy is used to address multiplicity. The registry record does not report a multiplicity strategy, an analysis plan, or which of the listed analyses were prespecified.
The primary endpoint itself has several categories or time points and is not reduced to one comparison in the registry record. The record describes the event types and the period up to 5 days postvaccination, but does not provide a single primary estimate or results by component. This means there is no basis in the listed details for determining how the endpoint categories were combined or how their results were compared.
Missing-data handling is also not reported in the registry record. The primary analysis population is described as vaccinated participants with documented initial consent, but the record does not specify how missing outcome observations, withdrawals, or participants without complete follow-up were handled. It does not report whether analyses used additional populations or sensitivity analyses.
Consequently, the listed outcome descriptions and analysis count are not enough to reconstruct the inferential framework. The available record does not establish whether reported findings, if any, account for multiple testing or missing observations. Those details are not reported in 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 |
|---|---|---|---|
| V116 | 29 | 527 | 5.5% |
| PPSV23 | 25 | 347 | 7.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| V116 | 0 of 531 |
| PPSV23 | 2 of 351 |
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 |
|---|---|
| V116 | 408 of 527 |
| PPSV23 | 237 of 347 |
Most frequent serious adverse event terms
| Event term | Organ system | V116 | PPSV23 |
|---|---|---|---|
| Asthma | Respiratory, thoracic and mediastinal disorders | 4 of 527 | 2 of 347 |
| Pneumonia | Infections and infestations | 3 of 527 | 1 of 347 |
| Urinary tract infection | Infections and infestations | 4 of 527 | 0 of 347 |
| Diabetic ketoacidosis | Metabolism and nutrition disorders | 3 of 527 | 1 of 347 |
| Dengue fever | Infections and infestations | 2 of 527 | 1 of 347 |
| Respiratory tract infection viral | Infections and infestations | 1 of 527 | 2 of 347 |
| Cardiogenic shock | Cardiac disorders | 2 of 527 | 0 of 347 |
| Anaphylactic reaction | Immune system disorders | 0 of 527 | 2 of 347 |
| Pneumonia viral | Infections and infestations | 2 of 527 | 0 of 347 |
| Viral infection | Infections and infestations | 1 of 527 | 1 of 347 |
Most frequent non-serious adverse event terms
| Event term | Organ system | V116 | PPSV23 |
|---|---|---|---|
| Injection site pain | General disorders | 357 of 527 | 189 of 347 |
| Injection site erythema | General disorders | 130 of 527 | 57 of 347 |
| Fatigue | General disorders | 107 of 527 | 73 of 347 |
| Injection site swelling | General disorders | 99 of 527 | 63 of 347 |
| Headache | Nervous system disorders | 94 of 527 | 53 of 347 |
| Malaise | General disorders | 70 of 527 | 33 of 347 |
| Irritability | Psychiatric disorders | 61 of 527 | 38 of 347 |
| Somnolence | Nervous system disorders | 50 of 527 | 32 of 347 |
| Pyrexia | General disorders | 33 of 527 | 25 of 347 |
| Myalgia | Musculoskeletal and connective tissue disorders | 34 of 527 | 18 of 347 |
Serious events with the highest arm-level rate: urinary tract infection (0.8%), asthma (0.8%), anaphylactic reaction (0.6%), respiratory tract infection viral (0.6%), pneumonia (0.6%).
The registry lists serious adverse events and other adverse events separately by study group. For serious adverse events, the V116 group is listed as 29 affected among 527 at risk, and the PPSV23 group as 25 affected among 347 at risk. For other adverse events, the corresponding figures are 408 among 527 and 237 among 347. These numbers describe the registry entries; they are not a statistical test or an adjusted comparison. The record does not provide confidence intervals or a comparative effect estimate for these counts in the registry record for this analysis.
The registry lists 0 deaths in the V116 group and 2 in the PPSV23 group. A death count does not identify its cause or establish whether it was related to study intervention. Timing, circumstances, and attribution are not reported in the registry record.
Serious adverse-event terms listed with percentages are urinary tract infection and asthma at 0.8% each, and anaphylactic reaction, respiratory tract infection viral, pneumonia, and diabetic ketoacidosis at 0.6% each. The denominator and arm assignment for these term-level percentages are not reported in the registry record. They should therefore be read as listed frequencies, not as a basis for comparing the groups or attributing an event to a vaccine.
In general, safety interpretation depends on event definitions, follow-up, participant exposure, missing observations, and context, in addition to counts. Those details should not be inferred from these figures alone.
12. What the Result Does, and Does Not, Mean
The record documents a randomized, double-blind Phase 3 study comparing V116 with PPSV23 among children and adolescents at increased risk of pneumococcal disease. It identifies a primary safety outcome focused on solicited injection-site events up to 5 days after vaccination, and it lists secondary antibody-response outcomes. It also records serious and other adverse-event counts and death counts by group. These details describe the study and selected posted safety data.
The record does not report a single primary endpoint comparison or its result. It also does not report the comparative antibody-response values, confidence intervals, or statistical tests in the registry record for this analysis. The study’s stated purpose—to evaluate safety, tolerability, and immunogenicity, and to compare antibody response—is not a finding. Neither the vaccine descriptions nor the outcome names establish the direction or size of a treatment effect.
The serious and other adverse-event counts are descriptive. Without a reported comparative estimate and its uncertainty, they do not show how precisely the groups differ. The death counts do not establish cause or relationship to vaccination. The listed serious adverse-event term percentages lack a reported denominator and group assignment in the registry record, which limits their interpretation.
In general, a clinical result is interpreted by considering the estimated effect, its uncertainty, the outcome definition, the analysis population, missing data, and the study’s prespecified methods. Those elements are not all. The registry record therefore does not support a conclusion about whether V116 differs from PPSV23 on the primary endpoint, whether any difference is statistically distinguishable from chance, or whether an observed difference would be clinically important.
These limitations do not mean that no analysis was conducted; they mean that the registry entries available in the registry record do not show the results needed to evaluate it. The trial is recorded as completed, but completion status alone does not provide evidence about an outcome.
13. Why This Trial Matters Statistically
This trial is statistically notable because it places a safety endpoint and immunogenicity outcomes in the same randomized comparison. Those outcome types answer different questions. The primary endpoint concerns solicited local adverse events after vaccination, while the listed secondary outcomes concern antibody concentrations and changes in serotype-specific immune measures. Keeping those interpretations distinct helps prevent an immunogenicity measure from being treated as a safety result or a clinical disease outcome.
The population is also specifically described: children and adolescents aged 2 through 17 years who completed routine pneumococcal vaccination as infants or toddlers and had increased risk of pneumococcal disease. The relevance of any result would depend on how closely the analyzed participants and outcomes match that stated population and purpose. Further population details are not reported in the registry record.
The entry lists nine outcome measures and 55 analyses. That breadth makes transparent reporting of endpoint hierarchy, multiplicity handling, analysis populations, and uncertainty especially important. These methods are not reported in the registry record. Without a single primary comparison and its uncertainty, readers cannot distinguish a clear estimate from a result that remains imprecise, nor can they assess the role of multiple analyses.
The listed safety counts are useful descriptive information, but they are not a substitute for an effect estimate with a defined analysis and uncertainty. Similarly, trial completion and the stated aim of assessing antibody response do not establish what the observed responses were. Statistically, the central lesson is to separate study design and endpoint definitions from numerical findings, and to treat unavailable inferential details as unresolved rather than filling them in by assumption.
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 endpoint is described, but the registry record flags that it has several categories or time points and is not reduced to one comparison. The record therefore does not provide a single estimate for the primary safety question. It also does not provide the component-level results for pain or tenderness, redness or erythema, and swelling, or explain how these categories contribute to the overall endpoint.
Although the record lists safety counts by group, it does not report confidence intervals, comparative effect estimates, or statistical tests for them in the registry record for this analysis. For the listed serious adverse-event terms, the denominator and arm assignment are not reported. The death counts are not accompanied by causes, timing, or attribution. These omissions prevent detailed comparative interpretation.
The registry lists immunogenicity outcomes but does not report their numerical results in the registry record. The record also does not report a statistical analysis plan, missing-data methods, multiplicity handling, interim analyses, or a sample-size justification. Enrollment is listed as 882, but the group-specific numbers randomized or analyzed are not reported in the registry record for this analysis.
These limitations concern what is reported in the registry record. They do not establish that the study did not collect or analyze additional information. They do mean that a reader cannot reconstruct the primary analysis, evaluate its precision, or assess the full comparative safety and immunogenicity findings from the listed details alone.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Clinical Study of the V116 Vaccine for Children and Teenagers (V116-013) — NCT06177912.
- Registry record last updated 2026-03-11; status last verified 2026-03.
- Results first posted 2026-03-11.
- 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
NCT06177912 is a completed Phase 3 randomized, double-blind, parallel-group study of V116 versus PPSV23 in children and adolescents at increased risk of pneumococcal disease. Enrollment is listed as 882; the study began on 2024-01-18 and reached primary completion on 2025-02-26. Both groups received a single 0.5 mL intramuscular dose on Day 1.
The primary outcome is the percentage of participants with solicited injection-site adverse events up to 5 days after vaccination. The registry record does not report a single reduced comparison or its result. It lists secondary outcomes concerning serotype-specific antibody measures, along with safety counts and deaths by group. Comparative estimates, uncertainty measures, and key analysis details are not reported in the registry record in the registry record for this analysis.