This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Study Evaluating A 13-Valent Pneumococcal Conjugate Vaccine Administered to Infants in Taiwan (NCT00688870), a randomized phase 3 study. The primary outcome is Percentage of Participants Achieving a Predefined Antibody Level of Greater Than or Equal to 0.35 Micrograms (mcg)/mL, 1 Month After the Infant Series..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00688870 |
| Phase | Phase 3 |
| Condition | Vaccines, Pneumococcal Conjugate Vaccine |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 168 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Wyeth is now a wholly owned subsidiary of Pfizer |
| Results posted | Yes |
2. Clinical Question
Population
Healthy infants in Taiwan who received routine pediatric vaccinations. The primary immunogenicity endpoint was defined for an evaluable population: participants had to receive treatment as randomized at all 3 doses, have blood drawn within specified timeframes, have at least 1 valid and determinate assay result for the proposed analysis, and have no major protocol violations.
Intervention
The intervention was the 13-valent pneumococcal conjugate vaccine, abbreviated 13vPnC, administered with routine pediatric vaccination. The study assessed safety, tolerability, and immunogenicity.
Comparator
The active comparator was the 7-valent pneumococcal conjugate vaccine, abbreviated 7vPnC, also administered with routine pediatric vaccination. The trial was randomized, double-blind, and parallel-group.
Primary question
One month after the infant series, at 7 months of age, what percentage of evaluable participants achieved an antibody level of at least 0.35 mcg/mL for each of the 7 common pneumococcal serotypes and the 6 additional serotypes specific to 13vPnC?
The clinical question is about immune responses measured by antibody levels, not directly about illness or prevention of disease. The registry defines a threshold-based outcome and specifies that percentages and exact 95% confidence intervals were to be reported for the serotypes. The numerical primary outcome estimates and confidence intervals are not reported in the registry record available for this analysis. Therefore, the record supports describing the endpoint and the comparison being asked, but not stating which vaccine had higher antibody-response percentages or how precise any observed difference was.
A secondary outcome concerned the percentage reaching the same antibody threshold 1 month after the toddler dose. Numerical results for that outcome are also not reported in the registry record. The study’s stated purpose was to assess the vaccines when given concomitantly with routine vaccines in Taiwan; the record does not establish conclusions beyond the measured safety and immunogenicity outcomes.
3. Trial Design
The registry describes a phase 3, randomized, active-controlled, double-blind, parallel-group trial. The study compared 13vPnC with 7vPnC in healthy infants in Taiwan, with both vaccines administered alongside routine pediatric vaccination. The active comparator makes the main contrast one vaccine regimen versus another rather than vaccination versus no vaccine. The registry lists enrollment as 168.
The trial record gives the study start as 2008-06-05, primary completion as 2010-01-13, and status as completed. It identifies the sponsor as Wyeth, now a wholly owned subsidiary of Pfizer. The registry labels masking as double, but does not report in this record which specific trial roles were masked or how masking was maintained. The method used to generate the randomization sequence and the method used to conceal allocation are not reported in the registry record.
The primary immunogenicity assessment was scheduled 1 month after the infant series, at 7 months of age. It evaluated whether a participant crossed the stated antibody threshold for each of the 7 serotypes common to both vaccines and the 6 additional serotypes specific to 13vPnC. The evaluable immunogenicity population required treatment as randomized at all 3 doses, appropriately timed blood collection, at least 1 valid and determinate assay result for the analysis, and no major protocol violations. This definition is narrower than simply being enrolled or randomized, though the record does not provide a full flow of participants from enrollment through each analysis.
Safety information is separated into the infant series, the period after the infant series, and the toddler dose. Counts at risk and counts with serious or other adverse events are reported for those periods. The registry does not report the complete schedule details, the precise follow-up duration for each safety interval, or the methods used to collect and adjudicate adverse events in the information available for this analysis. The study is marked completed, but completion alone does not supply missing outcome estimates or details of the statistical analysis plan.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: A total of 169 subjects were screened, 168 subjects were randomly assigned in a 1:1 ratio to either the 13vPnC group (n=84) or the 7vPnC group (n=84).
Infant Series
| Stage | 13vPnC | 7vPnC |
|---|---|---|
| STARTED | 84 | 84 |
| Vaccinated Dose 1 | 83 | 84 |
| Vaccinated Dose 2 | 80 | 84 |
| Vaccinated Dose 3 | 80 | 84 |
| COMPLETED | 80 | 84 |
| NOT COMPLETED | 4 | 0 |
Reasons for not completing this period:
| Reason | 13vPnC | 7vPnC |
|---|---|---|
| Parent or legal guardian request | 4 | 0 |
After Infant Series
| Stage | 13vPnC | 7vPnC |
|---|---|---|
| STARTED | 80 | 84 |
| COMPLETED | 80 | 84 |
| NOT COMPLETED | 0 | 0 |
Toddler Dose
| Stage | 13vPnC | 7vPnC |
|---|---|---|
| STARTED | 80 | 84 |
| COMPLETED | 80 | 84 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Evaluable immunogenicity population: had treatments as randomized at all 3 doses, blood drawn within specified timeframes, had at least 1 valid and determinate assay result for the proposed analysis, and no major protocol violations.
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 | 13vPnC | 7vPnC | Total |
|---|---|---|---|---|
| Participants analysed | 84 | 84 | 168 | |
| Age, Continuous | months | 2.2 (SD 0.3) | 2.3 (SD 0.3) | 2.2 (SD 0.3) |
| Sex: Female, Male: Female | Participants | 40 | 47 | 87 |
| Sex: Female, Male: Male | Participants | 44 | 37 | 81 |
| Region of Enrollment: Taiwan, Province Of China | Participants | 84 | 84 | 168 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants Achieving a Predefined Antibody Level of Greater Than or Equal to 0.35 Micrograms (mcg)/mL, 1 Month After the Infant Series., measured over 1 month after the infant series (7 months of age).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants whose antibody level met or exceeded 0.35 mcg/mL 1 month after the infant series, at 7 months of age. The threshold is applied separately to the 7 serotypes common to 13vPnC and 7vPnC and the 6 additional serotypes specific to 13vPnC. The registry specifies an exact 95% confidence interval for each reported percentage.
Antibody concentration is an immunogenicity measure: it describes a biological response to vaccination. A threshold-based percentage is useful because it expresses how many participants in an analysis population reached a defined level, rather than only describing an average antibody concentration. Reporting serotypes separately also retains information about responses to individual components rather than collapsing them into one overall value. These are general explanations of the statistical and measurement roles of such outcomes; they do not establish that the threshold predicts protection in this trial.
The evaluable immunogenicity population was restricted by treatment received, blood-draw timing, assay availability, and protocol compliance. Consequently, the endpoint describes participants meeting those criteria, not necessarily every enrolled or randomized participant. The registry record available for this analysis gives the endpoint definition but not the observed percentages or their confidence intervals. It is therefore not possible to interpret the magnitude, direction, or precision of the primary antibody-response findings from this record alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record clearly identifies the main immunogenicity question: compare threshold attainment for each specified pneumococcal serotype after the infant series. It also specifies the assessment time, antibody threshold, analysis population, and intended confidence interval. These details define what the outcome means and the conditions under which it was to be assessed. They do not, by themselves, give the results of that assessment.
Numerical primary outcome percentages and exact confidence intervals are not reported in the registry record available for this analysis. Thus, there is no basis for describing the observed antibody response in either arm, comparing the arms for any serotype, or assessing whether an estimate is precise or uncertain. It would be inappropriate to infer an immunogenicity result from the vaccine names, the study design, or the stated endpoint. The secondary antibody outcome after the toddler dose likewise has no numerical result in this record.
The safety information is more concrete but remains limited to counts by study period. In the infant-series period, serious adverse events were reported for 4 participants at risk in the 13vPnC group and 4 at risk in the 7vPnC group. After the infant series, the corresponding counts were 12 of 83 and 9 of 84. At the toddler dose, the counts were 0 of 80 and 3 of 84. These are descriptive event counts for the listed periods; they are not adjusted comparisons, and the registry record does not provide a statistical test or confidence interval for between-group differences in serious adverse events.
The at-risk counts are not identical across all periods. The record does not explain the reasons for the changes in denominators, so they should not be attributed to withdrawal, missing visits, or any other specific cause. Nor should counts from different periods be added: each period represents a distinct reporting window, and a participant may contribute to more than one window. The record also lists serious-event terms with percentages, but those term-level figures do not provide a complete account of event timing, recurrence, or attribution to vaccination.
The result that can be read responsibly is therefore limited: the registry defines a comparative immunogenicity trial and reports some period-specific safety counts, but the primary numerical immunogenicity findings are absent from the available record. The safety counts describe what was recorded, not whether one vaccine caused more events or whether an observed difference is compatible with chance. Without outcome estimates, uncertainty intervals, analysis details, and complete follow-up information, stronger comparative conclusions are not supported.
9. Statistical Methods Explained
What does a threshold percentage describe?
For a binary endpoint, each participant is classified according to whether the measured antibody level reached the specified threshold. The percentage is the proportion of participants in the analysis population who met that criterion. This format is easy to interpret as a response rate, but it depends on the threshold, the assay, the timing of specimen collection, and the population included in the analysis. In this trial, the stated threshold is 0.35 mcg/mL, and the primary assessment is 1 month after the infant series.
The endpoint is assessed separately for each serotype. A participant can meet the threshold for one serotype and not another, so a collection of serotype-specific response percentages should not be read as a single overall response rate. The registry lists 7 common serotypes and 6 additional serotypes specific to 13vPnC. The posted record available for this analysis does not contain the numerical percentages for those outcomes.
How should a confidence interval be read?
General explanation: a confidence interval communicates uncertainty around an estimated quantity. For a percentage, it helps show how much imprecision is consistent with the observed data under the method used. A narrower interval generally indicates a more precise estimate, while a wider interval indicates less precision. A 95% confidence interval is not a statement that there is a 95% probability that a fixed true value lies inside this particular interval. Rather, the confidence level describes the long-run performance of the procedure under its assumptions.
The registry specifies exact 95% confidence intervals for the serotype-specific percentages. Exact methods are designed for proportion data, particularly when simple large-sample approximations may be unreliable. However, no interval limits are reported in the record available for this analysis. No conclusion about the precision of the primary endpoint estimates can be made without those limits.
What does randomization contribute?
General explanation: random assignment aims to make treatment groups comparable, on average, with respect to both measured and unmeasured baseline characteristics. That supports interpreting a between-group contrast as an effect of assigned treatment, provided the trial is conducted and analyzed appropriately. Randomization does not guarantee that every characteristic will be balanced in a particular trial, and it does not resolve problems caused by missing outcomes, protocol deviations, or incomplete reporting.
This registry describes the study as randomized, active-controlled, double-blind, and parallel-group. The record does not report the sequence-generation procedure, allocation concealment method, or which roles were masked. The groups are described as 13vPnC and 7vPnC. The design label alone cannot establish how well these safeguards were implemented.
Why do analysis populations matter?
The primary endpoint uses an evaluable immunogenicity population. Eligibility for that population required participants to have treatment as randomized at all 3 doses, blood drawn within specified timeframes, at least 1 valid and determinate assay result for the proposed analysis, and no major protocol violations. Such restrictions can make the antibody measurements more directly aligned with the planned schedule and usable assay results. They also mean the estimand described by the endpoint is not automatically the outcome among all randomized participants.
General explanation: excluding participants can affect interpretation if inclusion is related to treatment group, response, or other factors. A clear participant flow and sensitivity analyses can help readers assess that concern. The available registry record does not report a complete flow by analysis population or sensitivity analyses for the primary endpoint. It also does not report the handling of missing assay values beyond the evaluability criteria.
What is and is not reported about statistical analysis?
The registry identifies the endpoint measure and its confidence interval, but the statistical analysis plan, any hypothesis test, model, covariate adjustment, and handling of multiplicity are not reported in the registry record available for this analysis. The absence of those details prevents a full assessment of how the planned comparisons were implemented. It also means that no p-value or adjusted comparison should be inferred from the endpoint definition.
General explanation: multiplicity arises when many outcomes or subgroup comparisons are assessed. With more opportunities to find a difference by chance, a prespecified strategy may be needed to control the interpretation of statistical tests. Separate serotype-specific percentages are clinically and scientifically informative, but a series of estimates does not establish which comparisons were confirmatory or whether any adjustment was planned. The record does not report such a strategy.
The planning illustrations use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. They are planning illustrations, not observed power and not evidence about the trial’s original design justification. The registry record does not report the original sample-size justification. These planning assumptions cannot fill in absent observed immunogenicity results or substitute for the trial’s analysis plan.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome is not a single pooled measure: it is reported separately for the 7 serotypes common to both vaccines and the 6 additional serotypes specific to 13vPnC. The registry also identifies a secondary antibody-threshold outcome after the toddler dose and reports multiple safety outcomes. This creates several possible results to interpret. The statistical plan for prioritizing comparisons or controlling multiplicity is not reported in the registry record. Without that information, it is not possible to determine which findings, if any, were intended as confirmatory or whether an adjustment was planned.
Missing-data handling is also not reported in detail. The evaluable immunogenicity population required treatment as randomized at all 3 doses, blood collection within specified timeframes, at least 1 valid and determinate assay result, and no major protocol violations. These criteria define who could contribute to a proposed analysis, but they do not explain how many participants were excluded from each serotype analysis, why data were unavailable, or whether any missing values were imputed. The record does not report a sensitivity analysis addressing missing antibody measurements.
For safety, the registry gives at-risk denominators for each period, and those denominators differ across periods. Reasons for those differences and the precise rules used to define each safety analysis set are not reported in the registry record. The record also does not report a complete participant disposition, detailed protocol deviations, or the statistical plan for safety comparisons. These omissions limit assessment of whether the reported populations and methods were comparable across arms and outcomes.
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 |
|---|---|---|---|
| Infant Series 13vPnC | 4 | 83 | 4.8% |
| Infant Series 7vPnC | 4 | 84 | 4.8% |
| After the Infant Series 13vPnC | 12 | 83 | 14.5% |
| After the Infant Series 7vPnC | 9 | 84 | 10.7% |
| Toddler Dose 13vPnC | 0 | 80 | 0.0% |
| Toddler Dose 7vPnC | 3 | 84 | 3.6% |
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 |
|---|---|
| Infant Series 13vPnC | 81 of 83 |
| Infant Series 7vPnC | 77 of 84 |
| After the Infant Series 13vPnC | 11 of 83 |
| After the Infant Series 7vPnC | 16 of 84 |
| Toddler Dose 13vPnC | 39 of 80 |
| Toddler Dose 7vPnC | 47 of 84 |
Most frequent serious adverse event terms
| Event term | Organ system | Infant Series 13vPnC | Infant Series 7vPnC | After the Infant Series 13vPnC | After the Infant Series 7vPnC | Toddler Dose 13vPnC | Toddler Dose 7vPnC |
|---|---|---|---|---|---|---|---|
| Gastroenteritis | Infections and infestations | 0 of 83 | 3 of 84 | 2 of 83 | 0 of 84 | 0 of 80 | 1 of 84 |
| Bronchiolitis | Infections and infestations | 1 of 83 | 0 of 84 | 2 of 83 | 2 of 84 | 0 of 80 | 0 of 84 |
| Urinary tract infection | Infections and infestations | 0 of 83 | 1 of 84 | 1 of 83 | 3 of 84 | 0 of 80 | 0 of 84 |
| Bronchopneumonia | Infections and infestations | 1 of 83 | 1 of 84 | 1 of 83 | 0 of 84 | 0 of 80 | 0 of 84 |
| Febrile convulsion | Nervous system disorders | 0 of 83 | 0 of 84 | 1 of 83 | 2 of 84 | 0 of 80 | 0 of 84 |
| Escherichia urinary tract infection | Infections and infestations | 1 of 83 | 0 of 84 | 1 of 83 | 0 of 84 | 0 of 80 | 0 of 84 |
| Croup infectious | Infections and infestations | 0 of 83 | 0 of 84 | 1 of 83 | 1 of 84 | 0 of 80 | 0 of 84 |
| Otitis media acute | Infections and infestations | 0 of 83 | 0 of 84 | 2 of 83 | 0 of 84 | 0 of 80 | 0 of 84 |
| Pharyngitis | Infections and infestations | 0 of 83 | 0 of 84 | 1 of 83 | 1 of 84 | 0 of 80 | 0 of 84 |
| Roseola | Infections and infestations | 0 of 83 | 0 of 84 | 1 of 83 | 1 of 84 | 0 of 80 | 0 of 84 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Infant Series 13vPnC | Infant Series 7vPnC | After the Infant Series 13vPnC | After the Infant Series 7vPnC | Toddler Dose 13vPnC | Toddler Dose 7vPnC |
|---|---|---|---|---|---|---|---|
| Irritability | General disorders | 52 of 80 | 56 of 80 | 0 of 0 | 0 of 0 | 18 of 65 | 20 of 74 |
| Decreased appetite | General disorders | 39 of 78 | 45 of 81 | 0 of 0 | 0 of 0 | 18 of 65 | 23 of 75 |
| Fever ≥ 38 degrees C but ≤ 39 degrees C | General disorders | 44 of 80 | 39 of 78 | 0 of 0 | 0 of 0 | 19 of 65 | 15 of 70 |
| Increased sleep | General disorders | 41 of 77 | 41 of 81 | 0 of 0 | 0 of 0 | 11 of 66 | 12 of 72 |
| Upper respiratory tract infection | Infections and infestations | 31 of 83 | 53 of 84 | 0 of 83 | 0 of 84 | 9 of 80 | 8 of 84 |
| Decreased sleep | General disorders | 35 of 79 | 32 of 78 | 0 of 0 | 0 of 0 | 11 of 64 | 17 of 74 |
| Irritability | General disorders | 42 of 75 | 46 of 80 | 0 of 0 | 0 of 0 | 0 of 0 | 0 of 0 |
| Decreased appetite | General disorders | 37 of 73 | 46 of 82 | 0 of 0 | 0 of 0 | 0 of 0 | 0 of 0 |
| Tenderness (any) | Skin and subcutaneous tissue disorders | 25 of 80 | 26 of 76 | 0 of 0 | 0 of 0 | 7 of 64 | 17 of 75 |
| Fever ≥ 38 degrees C but ≤ 39 degrees C | General disorders | 38 of 73 | 33 of 76 | 0 of 0 | 0 of 0 | 0 of 0 | 0 of 0 |
Serious events with the highest arm-level rate: gastroenteritis (3.6%), urinary tract infection (3.6%), bronchiolitis (2.4%), otitis media acute (2.4%), febrile convulsion (2.4%).
The serious adverse event counts are reported separately for the infant series, after the infant series, and the toddler dose. During the infant series, 4 of 83 participants at risk in the 13vPnC group and 4 of 84 in the 7vPnC group had a serious adverse event. After the infant series, the counts were 12 of 83 and 9 of 84. At the toddler dose, the counts were 0 of 80 and 3 of 84. These counts should be read within their respective periods, rather than combined across periods.
The registry also lists gastroenteritis at 3.6%, urinary tract infection at 3.6%, bronchiolitis at 2.4%, otitis media acute at 2.4%, febrile convulsion at 2.4%, and ileus at 1.2% among the serious-event terms. The record available for this analysis does not provide further detail needed to interpret these terms by treatment group, timing, recurrence, or causal attribution. The percentages should not be treated as a comparison between vaccines.
These are descriptive safety data. They do not by themselves show whether an event was caused by vaccination or establish that one group had a higher underlying risk. Statistical comparisons and confidence intervals for serious adverse events are not reported in the registry record. Death counts are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, double-blind, active-controlled study compared 13vPnC with 7vPnC in healthy infants in Taiwan, alongside routine pediatric vaccination. It specifies a threshold-based antibody endpoint after the infant series and a corresponding secondary assessment after the toddler dose. It also provides serious adverse event counts for separate study periods.
What the available record does not establish is the size or direction of the primary immunogenicity results. The numerical percentages and exact confidence intervals for the serotypes are not reported in the registry record. Without these estimates, there is no basis for saying that either vaccine produced higher threshold-attainment percentages, or for judging the precision of a comparison. The outcome definition alone is not an outcome result.
The safety counts likewise do not establish causation or a statistically reliable difference between groups. They are counts within reported risk sets and periods. The registry does not provide a reported statistical comparison, confidence interval, or attribution analysis for these serious events. The listed serious-event term percentages do not replace a complete description of timing, recurrence, or group-specific rates.
General explanation: a trial result is most informative when the estimated effect, its uncertainty, the analysis population, and the methods used to handle missing data and multiple outcomes can be considered together. Randomization helps support a comparative interpretation, but it does not make incomplete results complete. Here, the design and endpoint are described, while key numerical immunogenicity results and several analysis details are absent from the available record.
Accordingly, the most defensible interpretation is descriptive and bounded. The registry documents the trial question, the endpoint definition, the evaluable population criteria, and selected safety counts. It does not provide enough primary outcome information to characterize the observed antibody responses or their comparative precision. This account should not be read as medical advice or as a conclusion that either vaccine does or does not work.
13. Why This Trial Matters Statistically
This trial is statistically notable because its primary outcome is a set of serotype-specific threshold percentages rather than a single continuous measure. That structure preserves responses to the serotypes shared by the vaccines and to those specific to 13vPnC. It also makes interpretation dependent on careful attention to the individual estimates, their uncertainty, and the analysis population. The registry specifies exact 95% confidence intervals, a useful feature for showing the precision of each percentage when the numerical results are available.
The comparison is active-controlled and randomized, with both vaccines administered alongside routine pediatric vaccination. This gives the study a direct comparative structure for its safety and immunogenicity aims. The defined evaluable population also makes clear that the primary endpoint was intended to reflect participants with scheduled dosing, timely blood collection, usable assay results, and no major protocol violations. Those details matter when assessing what population the estimates would represent.
At the same time, the record illustrates why endpoint definitions and trial design cannot substitute for posted outcome estimates. The numerical primary antibody percentages and confidence intervals are not reported in the registry record available for this analysis. Nor are the statistical plan, multiplicity strategy, or detailed missing-data handling. Thus, the study question can be understood, but the central comparative immunogenicity result cannot be assessed from this information alone.
The period-specific safety counts offer another statistical lesson: denominators and follow-up windows must remain attached to their counts. Counts from different periods should not be combined, and descriptive event listings do not establish causal effects. A careful reader should distinguish the design’s capacity to address a question from the evidence actually available to answer it.
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 principal limitation for interpreting this trial from the registry record available for this analysis is the absence of numerical primary immunogenicity results. The record defines the antibody threshold, assessment time, serotypes, and evaluable population, but the percentages and exact confidence intervals are not reported. The secondary antibody outcome after the toddler dose is also described without numerical results. Consequently, the central comparative findings cannot be evaluated for magnitude, direction, or precision.
The analysis population is restricted by dosing, specimen timing, assay validity, and protocol compliance. The record does not give a complete participant flow or explain how many participants contributed to each serotype analysis. It does not detail missing-data procedures or report sensitivity analyses. These omissions make it difficult to judge how the evaluable population relates to all participants randomized.
Although the study is described as randomized and double-blind, the randomization procedure, allocation concealment, and specific masked roles are not reported in the record. The statistical analysis plan, any covariate adjustments, hypothesis tests, and multiplicity strategy are also not reported. The registry provides period-specific safety counts, but does not explain the changing at-risk denominators or provide statistical comparisons and uncertainty intervals for serious adverse events.
The serious-event term percentages are not accompanied in this record by the additional group, timing, recurrence, or attribution details needed for a fuller interpretation. Death counts are not reported in the registry record. These limitations concern what can be assessed from the available record; they should not be taken as proof that the trial did not collect or analyze information that is not reported.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study Evaluating A 13-Valent Pneumococcal Conjugate Vaccine Administered to Infants in Taiwan — NCT00688870.
- Registry record last updated 2022-10-07; status last verified 2022-09.
- Results first posted 2011-05-12.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry describes a completed phase 3 randomized, active-controlled, double-blind, parallel-group trial in healthy infants in Taiwan. It compared 13vPnC with 7vPnC, administered with routine pediatric vaccination, and lists enrollment as 168. The primary endpoint was the percentage reaching an antibody level of at least 0.35 mcg/mL 1 month after the infant series, assessed separately for the common and additional serotypes. The primary analysis population was evaluable immunogenicity participants meeting the specified dosing, blood-draw, assay, and protocol criteria.
The record also defines a secondary threshold outcome after the toddler dose and reports serious adverse event counts for the infant series, the period after the infant series, and the toddler dose. Numerical primary and secondary antibody results, their confidence intervals, detailed missing-data methods, and the multiplicity strategy are not reported in the registry record available for this analysis. Serious adverse event counts are descriptive, and death counts are not reported in the registry record.