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 Immunity to Serotype 19A Streptococcus Pneumoniae in Children Vaccinated With PCV10 (NCT04912297), a registered phase not stated study. The primary outcome is Persistence of Humoral Immunity Following PCV10 Vaccination.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04912297 |
| Phase | Phase not stated |
| Condition | Pneumococcal Infections |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 186 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Finnish Institute for Health and Welfare |
| Results posted | Yes |
2. Clinical Question
Population
Children vaccinated with PCV10 in Finland. The registry describes measurement of serotype 19A IgG concentrations two years following the last PCV vaccination. Overall enrollment was 186, but the number contributing to the primary outcome is not reported in the registry record.
Intervention
PCV10, described as the ten-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine. The registry includes a 2+1 schedule and a 3+1 schedule. It does not report an untreated or placebo group.
Comparator
The two schedules are described as study arms, but the record explicitly notes that this is not a randomized comparison and that allocation is not stated. The arms are not a like-for-like control comparison, so differences between their results would not by themselves establish an effect of schedule.
Primary question
What are the geometric mean serotype 19A IgG antibody concentrations, with 95% confidence intervals, two years after the last PCV10 vaccination among children vaccinated on either schedule? The registry describes this measurement but does not report the estimates.
The question is about persistence of a measured antibody response at a specified time after vaccination. It is not a reported comparison of clinical illness, protection, or a threshold-defined immune response. The registry’s brief summary places the work in the broader context of immunity to vaccine serotypes and vaccine-related serotypes, while the listed primary outcome specifically concerns serotype 19A IgG concentrations.
Because the study arms are not stated to be randomized and are expressly not described as like-for-like controls, the comparison has an important interpretive limit. Any difference between arm-level antibody estimates could reflect differences between the groups in addition to, or instead of, schedule. The registry record does not report how participants were allocated or whether other factors were accounted for.
3. Trial Design
The record describes a study of children vaccinated with PCV10 and an assessment of humoral immunity at a follow-up point two years after the last PCV vaccination. Overall enrollment is 186. The primary outcome population is described as subjects vaccinated with PCV10 on a 2+1 or 3+1 schedule, but the number assessed in either arm is not reported in the registry record.
The 2+1 schedule is described as two vaccinations with minimum 8-week intervals, followed by a booster dose at least 4 months after the last primary dose. The 3+1 schedule is described as three vaccinations with minimum 4-week intervals, followed by a booster dose at least 4 months after the last primary dose. These descriptions define the schedules as recorded; they do not establish that the arms differed only in the number or timing of doses.
The record identifies the study as completed. Its start date is 2009-11-12 and its primary completion date is 2013-05-07. These dates describe the registry record and do not supply additional information about individual follow-up or the timing of outcome collection beyond the stated two-year timeframe.
The comparison is not randomized, allocation is not stated, and the arms are not a like-for-like control comparison. The registry record does not report the method used to assign participants to schedules, whether assignment was prospective, or what other design features could affect comparability. It also does not report a protocol, masking, recruitment procedures, eligibility details, or a sample-size justification. Those details should not be inferred from the schedule descriptions or total enrollment.
There is one listed outcome measure and zero analyses reported in the registry record. Although the primary measure is described, the record does not give the arm-specific outcome estimates or confidence intervals. As a result, the study design and intended measurement can be described, but the antibody results cannot be summarized numerically from this 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.
Overall Study
| Stage | PCV10 2+1 Schedule | PCV10 3+1 Schedule |
|---|---|---|
| STARTED | 99 | 87 |
| COMPLETED | 68 | 54 |
| NOT COMPLETED | 31 | 33 |
Analysis population for the primary outcome, as defined in the registry: IgG concentrations to serotype 19A at two years following last PCV vaccination in subjects vaccinated with PCV10 with a 2+1 or 3+1 schedule
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 | PCV10 2+1 Schedule | PCV10 3+1 Schedule | Total |
|---|---|---|---|---|
| Participants analysed | 68 | 54 | 122 | |
| Age, Categorical: <=18 years | Participants | 68 | 54 | 122 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 33 | 25 | 58 |
| Sex: Female, Male: Male | Participants | 35 | 29 | 64 |
| Region of Enrollment: Finland | participants | 68 | 54 | 122 |
6. Primary Endpoint
The registry lists the primary outcome as Persistence of Humoral Immunity Following PCV10 Vaccination, measured over Two years following last PCV10 vaccination.
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | micrograms per ml |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the geometric mean concentration of serotype 19A-specific IgG antibodies, expressed in micrograms per ml, two years following the last PCV vaccination. The record describes this measure for children vaccinated with PCV10 using either schedule and specifies 95% confidence intervals for the reported geometric means.
Antibody concentration is a continuous laboratory measurement. A geometric mean is a way to summarize measurements when values are naturally considered on a multiplicative scale, such as concentrations that may vary over a broad range. In general, this summary is based on the mean of transformed values and then expressed back on the original scale. It is not the same as the arithmetic average, and it does not describe how many individual children had a particular concentration.
Measuring IgG provides a quantitative description of humoral immunity at the stated follow-up point. It can address persistence of an antibody response, which is the focus named in the registry record. The measure alone does not establish whether participants were protected from infection or whether a particular concentration is clinically adequate. The record does not state a protective threshold or report clinical outcomes linked to antibody levels.
The 95% confidence interval is intended to communicate uncertainty around the estimated geometric mean. In general, it reflects the precision of the estimate under the analysis assumptions; it is not a range containing 95% of individual participants’ antibody concentrations. The estimate and its interval are not reported in the registry record, so their magnitude and precision cannot be assessed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a specific descriptive outcome: serotype 19A IgG geometric mean concentrations two years after the last PCV vaccination, with 95% confidence intervals. It identifies children vaccinated on 2+1 and 3+1 schedules as the population of interest. However, it does not give the geometric means, confidence intervals, or numbers assessed for this outcome. Therefore, the posted record does not establish the level of antibody concentration observed or how precisely it was estimated.
The outcome description should not be mistaken for a reported finding. A measure and its units indicate what the study intended to summarize, but do not reveal the observed value. Without the estimates and intervals, it is not possible to describe the antibody concentrations as high, low, similar, different, persistent, or waning on the basis of the posted results. The two-year timing identifies when the outcome was to be assessed; it does not itself show what happened over time, because no earlier or later measurements are reported.
The registry identifies two schedule arms, but explicitly notes that this is not a randomized comparison, allocation is not stated, and the arms are not a like-for-like control comparison. A contrast between the schedules, if calculated from arm results, would therefore be descriptive rather than a secure causal estimate based on random assignment. The record does not describe an adjustment strategy that would address differences between groups.
Enrollment was 186, but that total does not show how many participants had an evaluable serotype 19A measurement at the follow-up point. The numbers at risk in the safety record are not a substitute for the primary outcome analysis population. Missing outcome counts, reasons for missingness, and the handling of missing measurements are not reported in the registry record.
For the same reasons, the record cannot support conclusions about clinical protection, infection rates, or the relative merits of the schedules. Its stated primary endpoint is an antibody concentration, not a clinical outcome. The available information establishes the research question and the intended statistical summary, while leaving the primary result itself unreported in the registry record.
9. Statistical Methods Explained
The primary measure is a geometric mean, and its uncertainty is described using a 95% confidence interval. These are useful summaries for continuous measurements such as antibody concentrations, but they answer different questions. The geometric mean summarizes the central level on a multiplicative scale; the confidence interval conveys uncertainty about that estimated central level. Neither quantity describes the full spread of individual measurements.
What does a geometric mean represent?
As a general statistical concept, a geometric mean is calculated by transforming positive values, averaging on the transformed scale, and converting the result back. This approach is often used when measurements are right-skewed or when proportional changes are more meaningful than equal-sized additive changes. For example, an equal proportional change at different starting concentrations need not correspond to the same absolute change. This is a general explanation of the statistic, not a claim about the distribution of the study’s measurements; that distribution is not reported in the registry record.
The registry names the unit as micrograms per ml and specifies a geometric mean for serotype 19A-specific IgG. It does not report the underlying observations, transformation details, handling of values below assay limits, or any other laboratory-data rules. Those methods should not be assumed.
How should a confidence interval be read?
In general, a confidence interval expresses uncertainty in an estimate using a method with a stated long-run coverage property, subject to its assumptions. A narrower interval indicates greater precision than a wider interval for the same kind of estimate. The interval is not a range intended to contain most individual antibody measurements, and it does not by itself establish clinical relevance. The registry specifies 95% confidence intervals but does not provide their endpoints or the method used to calculate them.
Because no geometric mean or interval is reported, precision cannot be evaluated for either schedule. Nor can the overlap or separation of the two intervals be assessed. Even if arm-specific intervals were available, a direct comparison would require attention to the contrast of interest and its uncertainty; comparing intervals by eye is not a substitute for estimating that contrast.
What does the nonrandomized comparison imply?
Random assignment can, in general, help make groups comparable with respect to both measured and unmeasured characteristics. Here, the registry explicitly states that the comparison is not randomized, allocation is not stated, and the arms are not a like-for-like control comparison. Consequently, an observed difference between schedule groups could reflect group composition or other differences, not only the schedules. The record does not report an adjusted analysis or enough design information to judge whether confounding was addressed.
The outcome is described as a measurement in participants vaccinated on either schedule, rather than as a reported randomized treatment effect. The statistical interpretation should therefore distinguish group summaries from causal effects. The registry record provides no analysis results to evaluate, and it reports zero analyses.
What do the planning illustrations mean?
The planning illustrations are based on the observed effect, use a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The intended effect to detect is expressed as a stated fraction of the observed effect. These are planning assumptions, not a description of the trial’s original design or a report of observed power. The registry record does not report the trial’s own sample-size justification, and no calculated participant counts are stated in the available record.
As a general concept, planning calculations describe the sample size associated with specified assumptions about an effect, variability, significance level, and power. They do not establish that the study had that power after enrollment, and they cannot compensate for missing outcome results or limitations in group comparability. Since the observed effect is not reported in the registry record, the effect-based planning illustrations cannot be independently interpreted from the registry information alone.
Why does over-dispersion matter?
For count outcomes, over-dispersion means that observed variability exceeds what a simpler probability model expects. In general, that can make standard errors too small if the extra variability is ignored. This trial’s listed primary endpoint is a continuous antibody concentration summarized as a geometric mean, not a count endpoint. The registry record does not describe an over-dispersion analysis, and no such method should be inferred from the endpoint description.
Overall, the statistical details available identify the type of summary and interval intended, but do not document the estimator’s implementation, covariate adjustment, missing-data handling, or analysis population. The estimates needed to judge observed levels and precision are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The record lists one outcome measure, the persistence of humoral immunity following PCV10 vaccination, with a serotype 19A-specific geometric mean and 95% confidence interval as the primary measure. The broader study aim mentions vaccine serotypes and vaccine-related serotypes, but the registry information does not list additional outcome estimates or explain whether other serotypes were assessed as secondary or exploratory outcomes.
Multiplicity arises when several hypotheses or outcomes are tested. In general, conducting many tests can increase the chance of at least one apparently notable result unless the analysis plan accounts for the number and relationship of the tests. The registry record does not report a multiplicity strategy, a hierarchy of outcomes, or whether any adjustment was planned. It also does not report an inferential comparison or p-value for the primary measure.
The analysis population is described as subjects vaccinated with PCV10 on either schedule, but the number included in the endpoint analysis is not reported in the registry record. Enrollment of 186 does not establish the number with an available antibody measurement at the two-year follow-up. The record does not explain whether all enrolled participants were included, how exclusions were handled, or whether analyses followed an intention-to-treat or per-protocol approach.
Missing-data amounts, reasons, and methods are also not reported in the registry record. In general, interpretation may depend on whether missing measurements are related to participant characteristics or outcomes, and on the assumptions used to address them. Without those details, it is not possible to assess potential bias from missing primary endpoint data. The absence of these reporting details does not prove that a particular method was or was not used; the methods are simply 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 |
|---|---|---|---|
| PCV10 2+1 Schedule | 0 | 68 | 0.0% |
| PCV10 3+1 Schedule | 0 | 54 | 0.0% |
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 |
|---|---|
| PCV10 2+1 Schedule | 0 of 68 |
| PCV10 3+1 Schedule | 0 of 54 |
The safety record lists 68 participants at risk in the PCV10 2+1 schedule group and 54 in the PCV10 3+1 schedule group. It reports 0 participants affected by serious adverse events in the 2+1 group and 0 in the 3+1 group. For other adverse events, it also reports 0 affected in each group. No serious adverse-event terms are listed.
These entries should be read as the adverse-event figures recorded for the listed groups, not as proof that no event could have occurred outside the record’s reporting scope. The registry does not provide further detail about the adverse-event collection period, definitions, ascertainment methods, or completeness of reporting. The death counts are not reported in the registry record.
The at-risk counts are safety denominators and should not be treated as the number contributing to the antibody endpoint. The safety entries also do not establish a comparative safety effect: the study arms are not described as randomized or like-for-like controls, and no statistical comparison is reported. These figures describe what the registry lists and do not support broader conclusions about safety.
12. What the Result Does, and Does Not, Mean
The record’s central statistical contribution is the definition of an antibody-persistence question: serotype 19A IgG geometric mean concentration, measured two years after the last PCV vaccination, among children vaccinated with PCV10 using a 2+1 or 3+1 schedule. It also specifies the unit and the intended use of 95% confidence intervals. These details clarify what outcome was of interest and how it was to be summarized.
The registry record does not report the primary endpoint estimates or their confidence intervals. It therefore does not show the observed antibody concentrations, their precision, or whether the two schedules had similar or different measured values. A reader cannot infer the missing results from the enrollment count, schedule descriptions, or safety entries.
Even if arm-specific outcome estimates were available, their interpretation would need to account for the design. The record states that this was not a randomized comparison, that allocation is not stated, and that the arms are not a like-for-like control comparison. A difference between groups would not automatically be attributable to schedule.
The endpoint is a laboratory measure of humoral immunity, not a reported clinical outcome. In general, an antibody concentration can describe an immune response, but it does not alone establish protection from infection or a clinical benefit. The registry does not state a protective threshold or link the measured concentrations to infection outcomes.
Accordingly, the record supports a description of the intended measurement and the study’s comparison structure, but not a conclusion about the magnitude, persistence, or clinical meaning of the observed response. Those results and the analysis details needed to interpret them are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically noteworthy because it focuses on persistence rather than only on a measurement immediately following vaccination. The specified assessment occurs two years after the last PCV vaccination, and the primary outcome is a quantitative serotype 19A IgG concentration summarized as a geometric mean with a 95% confidence interval. This makes the timing and scale of the intended measurement explicit.
The distinction between a descriptive antibody summary and a clinical endpoint matters. A geometric mean can characterize concentrations, while a clinical outcome would address events such as illness. The registry lists the former and does not report clinical outcomes linked to antibody concentrations. The statistical question and the clinical interpretation should therefore remain separate.
The record also illustrates why study design affects interpretation. Two schedules are described, but the comparison is not randomized, allocation is not stated, and the arms are not a like-for-like control comparison. This limits how confidently a difference could be attributed to schedule, even if outcome estimates were available. Statistical precision and causal interpretation are distinct: an estimate can be precise while still being vulnerable to group differences.
Finally, the entry underscores the importance of complete outcome reporting. The endpoint definition, units, timing, and confidence-interval type are useful, but the actual estimates and intervals are not reported. Without them, neither the magnitude of antibody concentrations nor their precision can be assessed. The registry record therefore helps frame the intended statistical question while leaving its numerical answer unavailable.
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 interpretation is that the registry record describes the primary endpoint but does not report its geometric mean estimates or 95% confidence intervals. It also does not state how many participants contributed measurements to either schedule group. Enrollment of 186 cannot be assumed to equal the endpoint analysis population.
The comparison has a design limitation explicitly noted in the record: it is not randomized, allocation is not stated, and the arms are not a like-for-like control comparison. The record does not provide enough information to assess how participants entered each schedule group or whether differences between groups were addressed analytically. Causal conclusions about schedule are therefore not supported by the information recorded.
Further details that would aid assessment are not reported in the registry record, including eligibility criteria, outcome-data completeness, reasons for missing measurements, laboratory assay procedures, handling of measurements outside assay limits, and the statistical method used to construct the confidence intervals. The record also does not state a sample-size justification, a multiplicity strategy, or a detailed analysis plan.
The listed endpoint measures antibody concentration rather than a clinical outcome. No protective threshold or relationship between antibody concentrations and infection is reported. Safety entries list no affected participants for the reported serious or other adverse-event categories, but the reporting period and ascertainment details are not stated; death counts are not reported in the registry record.
These limitations concern what can be concluded from the registry record and should not be treated as evidence that unreported procedures or data do not exist elsewhere. They mean that the numerical results, their precision, and the full analysis context cannot be evaluated from this record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Immunity to Serotype 19A Streptococcus Pneumoniae in Children Vaccinated With PCV10 — NCT04912297.
- Registry record last updated 2021-08-11; status last verified 2021-08.
- Results first posted 2021-08-10.
- 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 describes a completed study of persistence of humoral immunity to serotype 19A in children vaccinated with PCV10 in Finland. Overall enrollment was 186. The primary outcome is the serotype 19A-specific IgG geometric mean concentration, in micrograms per ml, two years after the last PCV vaccination, with 95% confidence intervals.
The described schedules are PCV10 2+1 and PCV10 3+1. The record states that this is not a randomized comparison, allocation is not stated, and the arms are not a like-for-like control comparison. It lists 68 and 54 participants at risk in the respective safety groups, with 0 affected by serious adverse events and 0 affected by other adverse events in each group. Death counts are not reported.
The primary outcome estimates, confidence intervals, endpoint analysis counts, missing-data handling, and detailed statistical plan are not reported in the registry record. Thus, the intended measurement is clear, but the observed antibody results and their precision cannot be assessed from the posted record.