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 an RSV Vaccine When Given to Adults 18 Years of Age and Above Who Received Lung or Kidney Transplant and Are at an Increased Risk of Respiratory Syncytial Virus Lower Respiratory Tract Disease and Compared to Healthy Adults 50 Years of Age and Above (NCT05921903), a randomized phase 2 study. The primary outcome is RSV-A Serum Neutralizing Titers Expressed As Mean Geometric Increase (MGI) Post-Dose 2 (Visit 4) Over Post-Dose 1 (Visit 3) for RSV_IC_2 Group.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05921903 |
| Phase | Phase 2 |
| Condition | Respiratory Syncytial Virus Infections |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 386 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GlaxoSmithKline |
| Results posted | Yes |
2. Clinical Question
Population
Adults at least 18 years of age who had received a lung or kidney transplant and healthy adults at least 50 years of age. The transplant recipients were described as immunocompromised and at increased risk of RSV lower respiratory tract disease.
Intervention
The RSVPreF3 OA investigational vaccine. Transplant recipients were assigned to a group receiving one dose or a group receiving two doses; healthy adults received one dose.
Comparator
The study compares the one-dose and two-dose transplant groups, and also compares transplant groups with healthy adults. The registry record does not report a placebo group.
Primary question
Among transplant recipients who received two doses, how did RSV-A serum neutralizing titers after dose two compare with titers after dose one? The primary measure is the geometric mean of each participant’s post-dose-two to post-dose-one titer ratio.
The study also set out to assess immunogenicity, safety, and reactogenicity, including whether a second vaccine dose increases the immune response in the transplant population. The primary endpoint is a within-participant comparison in the two-dose group; it is not a direct comparison between that group and the one-dose transplant group or healthy adults. Those broader group comparisons appear among the secondary outcomes, which include RSV-A and RSV-B neutralizing titers expressed as geometric mean titers.
The registry record identifies the study as completed, but does not report the primary endpoint result. It therefore does not establish from the posted record how large the within-person change was or how precisely it was estimated. The record also does not report a conclusion about whether a second dose increases the immune response.
3. Trial Design
This was a Phase 2b, randomized, controlled, open-label, parallel-group study of the RSVPreF3 OA investigational vaccine. The registry record lists 386 participants enrolled and identifies GlaxoSmithKline as the sponsor. The study started on 2023-07-28, had a primary completion date of 2024-06-25, and is listed as completed. Its condition is respiratory syncytial virus infections.
The study included adults at least 18 years of age who had received a lung or kidney transplant and healthy adults at least 50 years of age. The transplant participants were divided into a one-dose group and a two-dose group. The two-dose group received doses at Visit 1 (Day 1) and Visit 3, with Visit 3 scheduled 30-60 days after Visit 1. Healthy adult participants received one dose at Visit 1 (Day 1). The primary endpoint compared titers at Visit 4, scheduled 30-42 days after Visit 3, with titers at Visit 3 in the two-dose transplant group.
Randomization and a parallel design are stated in the registry record, but the randomization procedure, allocation ratio, and details of how participants were assigned to these groups are not reported in the registry record. Masking is listed as none, so the study was open-label. The record does not report a placebo arm. The primary endpoint uses a per protocol set for humoral immunogenicity; the complete criteria for that analysis population are not available in the registry record.
The study’s stated purpose included assessing immunogenicity, safety, and reactogenicity. The listed secondary outcomes focus on RSV-A and RSV-B serum neutralizing titers and geometric mean titers across the transplant and healthy adult groups. The registry record does not report the planned sample-size justification or a detailed 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: 386 participants were enrolled in the study, received at least 1 dose of the study intervention and were included in the Exposed set.
Overall Study
| Stage | RSV_IC_1 Group | RSV_IC_2 Group | RSV_HA Group |
|---|---|---|---|
| STARTED | 131 | 130 | 125 |
| COMPLETED | 129 | 125 | 123 |
| NOT COMPLETED | 2 | 5 | 2 |
Reasons for not completing this period:
| Reason | RSV_IC_1 Group | RSV_IC_2 Group | RSV_HA Group |
|---|---|---|---|
| Unsolicited non-SAE | 0 | 1 | 0 |
| SAEs/pIMDs/AESIs specific to SOT | 1 | 3 | 1 |
| Withdrawal by participant: burden of procedure | 0 | 1 | 0 |
| Withdrawal by participant: participant relocated | 1 | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Analysis was performed on Per protocol Set (PPS) for humoral immunogenicity, which included all participants who received the study intervention administration as per protocol, had immunogenicity results pre and post-dose, complied with blood draw intervals, without intercurrent conditions that may interfere with immunogenicity, without prohibited concomitant medication/vaccination. Only participants with data available for the RSV-A MGI at the specified timepoint were included in the analysis.
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.
Population: Exposed set included all participants that received at least one study intervention.
| Characteristic | Unit | RSV_IC_1 Group | RSV_IC_2 Group | RSV_HA Group | Total |
|---|---|---|---|---|---|
| Participants analysed | 131 | 130 | 125 | 386 | |
| Age, Continuous | YEARS | 62.1 (SD 9.3) | 61.4 (SD 8.4) | 63.8 (SD 8.2) | 62.4 (SD 8.7) |
| Sex: Female, Male: Female | Participants | 54 | 50 | 66 | 170 |
| Sex: Female, Male: Male | Participants | 77 | 80 | 59 | 216 |
| Race/Ethnicity, Customized: White | Participants | 89 | 79 | 95 | 263 |
| Race/Ethnicity, Customized: American Indian Or Alaska Native | Participants | 0 | 1 | 0 | 1 |
| Race/Ethnicity, Customized: Asian | Participants | 29 | 39 | 24 | 92 |
| Race/Ethnicity, Customized: Black Or African American | Participants | 11 | 8 | 4 | 23 |
| Race/Ethnicity, Customized: Not Reported | Participants | 1 | 2 | 0 | 3 |
| Race/Ethnicity, Customized: Multiple | Participants | 1 | 0 | 1 | 2 |
| Race/Ethnicity, Customized: Unknown | Participants | 0 | 1 | 1 | 2 |
6. Primary Endpoint
The registry lists the primary outcome as RSV-A Serum Neutralizing Titers Expressed As Mean Geometric Increase (MGI) Post-Dose 2 (Visit 4) Over Post-Dose 1 (Visit 3) for RSV_IC_2 Group, measured over At Visit 4 (Visit 3 + 30-42 days) compared with Visit 3 (Visit 1 [Day 1] + 30-60 days).
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Ratio |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the mean geometric increase in RSV-A serum neutralizing titers after dose two compared with after dose one, in the transplant-recipient group that received two doses. It is calculated as the geometric mean of the within-participant ratios: each participant’s post-dose-two titer divided by that participant’s post-dose-one titer. The time points are Visit 4, 30-42 days after Visit 3, and Visit 3, 30-60 days after Visit 1 (Day 1).
This measure is useful for describing a relative change on a multiplicative scale. Serum neutralizing titers are measurements of antibody activity; a geometric mean summarizes such measurements by taking account of their multiplicative rather than additive scale. Forming a ratio within each participant also makes the endpoint a comparison of that participant’s measurements across the two visits, rather than a comparison of separate group averages at each visit.
In general, a confidence interval describes the statistical uncertainty around an estimate and the range of values reasonably compatible with the data and analysis. The endpoint specifies a 95% confidence interval, but the numerical estimate and interval are not reported in the registry record. Therefore the size and precision of the observed mean geometric increase cannot be described from the posted record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record specifies an immunogenicity question rather than a clinical disease outcome as its primary endpoint. It asks how RSV-A neutralizing titers changed between post-dose-one and post-dose-two measurements among transplant recipients who received two doses. The endpoint is a within-participant geometric mean ratio, and its timeframe is defined relative to the study visits.
The primary numerical result, including the estimate and its 95% confidence interval, is not reported in the registry record. Consequently, the posted record does not allow readers to judge the magnitude of the measured change or its precision. It also does not report a primary-outcome hypothesis test or p-value. No conclusion about the effect of a second dose on antibody response can be drawn from the primary endpoint information available in the registry record alone.
The listed secondary outcomes compare geometric mean titers for RSV-A and RSV-B across groups, including the two transplant groups, pooled transplant participants, and healthy adults. The presence of these planned outcome descriptions does not itself show that the groups differed. Numerical results for those outcomes are not reported in the registry record for this analysis, so no direction, size, or precision of a between-group difference can be stated.
Safety counts are reported separately. In the one-dose transplant group, 29 of 131 participants were recorded as having a serious adverse event; in the two-dose transplant group, this was 37 of 130. In the healthy adult group, 4 of 125 participants were recorded as having a serious adverse event. Other adverse events were recorded for 106 of 131, 120 of 130, and 111 of 125 participants, respectively. The registry record lists 3 deaths in each transplant group and none in the healthy adult group. These are descriptive counts. They do not, by themselves, establish that the vaccine caused an event or that group differences are attributable to dose schedule or population.
Overall, the record identifies the study question, design, outcome definitions, and some adverse-event counts, but does not provide the numerical primary immunogenicity finding. The distinction between an outcome being specified and its result being reported is essential: the endpoint definition explains what was to be measured, not what the measurement showed.
9. Statistical Methods Explained
The primary endpoint is expressed as a geometric mean increase, constructed from within-participant ratios of RSV-A serum neutralizing titers. The analysis population is described as the per protocol set for humoral immunogenicity. The registry record gives part of that population description but not its full wording or complete criteria. Numerical primary endpoint results are not reported in the registry record.
What does a geometric mean summarize?
General statistical context: A geometric mean is a measure of central tendency suited to positive measurements that vary multiplicatively. Instead of averaging raw values in the usual additive way, the calculation uses logarithms, averages on the logarithmic scale, and transforms back. This can make the summary more appropriate when values span a wide range or when proportional changes are more meaningful than absolute changes.
For this endpoint, the ratio is formed within each participant, comparing the post-dose-two titer with the post-dose-one titer. The geometric mean of these ratios summarizes the group’s typical proportional change on the multiplicative scale. It is not the same as subtracting the group’s average pre-dose value from its average post-dose value. The endpoint description gives the calculation, but not the numerical estimate.
What does the confidence interval contribute?
General statistical context: A confidence interval communicates uncertainty around an estimate. A narrower interval indicates greater statistical precision under the analysis assumptions; a wider interval indicates less precision. The stated 95% confidence interval would help readers assess how precisely the geometric mean increase was estimated. Because its numerical limits are not reported in the registry record, precision cannot be assessed for this endpoint.
A confidence interval is not a measure of clinical importance by itself. Interpretation also depends on the endpoint, the question being asked, and the relevance of the measured change. Here, the registry record defines a laboratory immunogenicity endpoint. It does not report a clinical disease endpoint as the primary outcome.
Why use a within-participant comparison?
General statistical context: Measurements from the same participant are often related. A paired comparison accounts for that relationship by comparing each participant with their own earlier measurement. This can reduce the influence of between-person differences on the estimated change, provided the relevant measurements are available and the analysis is conducted as specified. The primary endpoint is explicitly defined using within-participant ratios. The registry record does not provide the numerical results or enough detail to assess how missing paired measurements were handled.
What do the groups contribute?
The two-dose transplant group supplies the observations for the primary endpoint. The one-dose transplant group and healthy adult group provide context for secondary group comparisons, including RSV-A and RSV-B geometric mean titers. The primary endpoint itself is not a randomized comparison between the one-dose and two-dose transplant groups: it compares post-dose-two with post-dose-one measurements within the two-dose group. Group comparisons should therefore be read according to their stated outcome and analysis, rather than inferred from the primary endpoint definition.
How should sample-size illustrations be understood?
General statistical context: A sample-size calculation asks how many participants may be needed to detect a specified effect under stated assumptions. It does not describe what the observed data show and is not a measure of observed power. The registry record does not report the trial’s own sample-size justification. Any planning illustrations based on the observed effect are not the trial’s original design justification; they use a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. These illustrations should not be interpreted as evidence that the trial had a particular probability of detecting an effect.
In general, sample-size illustrations are sensitive to the assumed effect, variability, allocation, and analysis method. A calculation based on an effect observed after the study is complete can describe a hypothetical planning scenario, but it cannot replace a prespecified design rationale or establish that an analysis was adequately powered. The registry record does not report the assumptions used for the original enrollment target.
What can be concluded from an absent result?
The endpoint definition and the existence of a confidence-interval method do not reveal the result. Without the estimate and interval, neither the direction nor magnitude of the primary change can be evaluated. A result absent from the registry record should not be treated as a null result, evidence of no change, or evidence of a change. It means only that the relevant numerical finding is not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 20 outcome measures and 22 analyses, including secondary outcomes for RSV-A and RSV-B geometric mean titers across several groups. It does not report whether or how multiplicity was controlled. When several outcomes or comparisons are examined, the chance of at least one apparently unusual result can increase if each is assessed independently. In general, prespecified testing hierarchies or other multiplicity procedures can address that concern, but the registry record does not identify such a procedure. No adjusted or unadjusted p-values for these outcomes are reported in the record available for this analysis.
The primary endpoint population is described as the per protocol set for humoral immunogenicity. The description states that it included participants who received study intervention as per protocol, had immunogenicity results before and after dosing, complied with blood-draw intervals, and did not have intercurrent conditions that may affect the assessment. The registry record’s wording for the last criterion is incomplete, so its full definition is not reported in the registry record.
The record does not describe how missing titers, missed visits, withdrawals, or other incomplete observations were handled. It also does not report whether sensitivity analyses were used to assess the effect of missing data, or whether the safety analyses used a different analysis population. Such details matter because analysis-population rules and missing-data methods can influence which participants contribute to an estimate. They cannot be inferred from the endpoint definition or the enrollment total.
The registry record does not report the full statistical analysis plan, including any prespecified approach to multiplicity, missing observations, or analysis deviations. These omissions limit assessment of how the listed outcomes and populations were analyzed.
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 |
|---|---|---|---|
| RSV_IC_1 Group | 29 | 131 | 22.1% |
| RSV_IC_2 Group | 37 | 130 | 28.5% |
| RSV_HA Group | 4 | 125 | 3.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| RSV_IC_1 Group | 3 of 131 |
| RSV_IC_2 Group | 3 of 130 |
| RSV_HA Group | 0 of 125 |
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 |
|---|---|
| RSV_IC_1 Group | 106 of 131 |
| RSV_IC_2 Group | 120 of 130 |
| RSV_HA Group | 111 of 125 |
Most frequent serious adverse event terms
| Event term | Organ system | RSV_IC_1 Group | RSV_IC_2 Group | RSV_HA Group |
|---|---|---|---|---|
| Pneumonia | Infections and infestations | 3 of 131 | 5 of 130 | 0 of 125 |
| Sepsis | Infections and infestations | 1 of 131 | 4 of 130 | 0 of 125 |
| COVID-19 | Infections and infestations | 0 of 131 | 4 of 130 | 0 of 125 |
| Urinary tract infection | Infections and infestations | 2 of 131 | 2 of 130 | 0 of 125 |
| Gastroenteritis | Infections and infestations | 2 of 131 | 1 of 130 | 0 of 125 |
| Urosepsis | Infections and infestations | 1 of 131 | 2 of 130 | 0 of 125 |
| Acute kidney injury | Renal and urinary disorders | 0 of 131 | 3 of 130 | 0 of 125 |
| Pyrexia | General disorders | 0 of 131 | 3 of 130 | 0 of 125 |
| Colitis | Gastrointestinal disorders | 0 of 131 | 2 of 130 | 0 of 125 |
| Urinary retention | Renal and urinary disorders | 0 of 131 | 2 of 130 | 0 of 125 |
Most frequent non-serious adverse event terms
| Event term | Organ system | RSV_IC_1 Group | RSV_IC_2 Group | RSV_HA Group |
|---|---|---|---|---|
| Administration site pain | General disorders | 95 of 131 | 108 of 130 | 95 of 125 |
| Fatigue | General disorders | 41 of 131 | 61 of 130 | 49 of 125 |
| Myalgia | Musculoskeletal and connective tissue disorders | 38 of 131 | 56 of 130 | 49 of 125 |
| Headache | Nervous system disorders | 32 of 131 | 46 of 130 | 44 of 125 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 19 of 131 | 27 of 130 | 15 of 125 |
| Administration site erythema | General disorders | 8 of 131 | 19 of 130 | 11 of 125 |
| Administration site swelling | General disorders | 8 of 131 | 13 of 130 | 3 of 125 |
| Pyrexia | General disorders | 3 of 131 | 3 of 130 | 1 of 125 |
| Nasopharyngitis | Infections and infestations | 0 of 131 | 4 of 130 | 2 of 125 |
| Oropharyngeal pain | Respiratory, thoracic and mediastinal disorders | 1 of 131 | 1 of 130 | 4 of 125 |
Serious events with the highest arm-level rate: pneumonia (3.8%), sepsis (3.1%), covid-19 (3.1%), acute kidney injury (2.3%), pyrexia (2.3%).
The registry record reports serious adverse events and other adverse events by study group, along with deaths. Serious adverse events were recorded for 29 of 131 participants in the one-dose transplant group, 37 of 130 in the two-dose transplant group, and 4 of 125 in the healthy adult group. Other adverse events were recorded for 106 of 131, 120 of 130, and 111 of 125 participants, respectively. Deaths were recorded for 3 participants in each transplant group and none in the healthy adult group.
The most frequently listed serious-event terms are pneumonia (3.8%), sepsis (3.1%), COVID-19 (3.1%), acute kidney injury (2.3%), pyrexia (2.3%), and urinary tract infection (1.5%). These percentages describe the posted serious-event terms; the registry record does not provide additional context about timing, event attribution, or overlap among terms.
These counts are descriptive, not proof that the vaccine caused an event or that one group’s schedule was safer than another’s. The groups differ in population, and the record does not report a statistical comparison of safety outcomes. The serious-event counts should also be distinguished from the other-adverse-event counts and from the death counts.
12. What the Result Does, and Does Not, Mean
The study was designed to assess immune response and safety after RSVPreF3 OA vaccination in lung and kidney transplant recipients and healthy adults. Its primary endpoint asks about the change in RSV-A neutralizing titers between post-dose-one and post-dose-two visits in the transplant group receiving two doses. That is a specific laboratory immunogenicity question, not a direct measure of prevention of RSV infection or lower respiratory tract disease.
The registry record does not report the primary endpoint estimate or its 95% confidence interval. It therefore does not show the size or precision of the measured change. Nor does the endpoint definition alone show that the second dose increased the immune response. A planned measure is not a result, and an absent result cannot be interpreted as either evidence of an effect or evidence of no effect.
The secondary outcomes describe planned comparisons of RSV-A and RSV-B neutralizing titers across groups. Their numerical results are not reported in the registry record available for this analysis. The record’s safety counts provide descriptive information on serious and other adverse events and deaths, but they do not establish causation or a comparative safety effect.
In general, antibody measurements can help characterize an immune response, while clinical outcomes address whether participants experienced disease-related events. The posted primary endpoint is an antibody-titer measure. The record does not report a primary clinical disease outcome, and it does not provide enough numerical immunogenicity results to assess the primary question’s observed answer.
The trial record is therefore informative about the study’s structure, population, dosing schedules, endpoint definition, and some safety counts. It does not support a conclusion about the magnitude of immune response, the value of a second dose, or clinical protection from RSV based on the primary result, because that result is not reported in the registry record.
13. Why This Trial Matters Statistically
This study raises a statistical question that is distinct from a simple comparison of vaccine recipients with an untreated group. Its primary endpoint uses repeated measurements from the same transplant recipients, comparing their RSV-A neutralizing titers after dose two with their titers after dose one. This makes the endpoint a within-participant change, summarized as a geometric mean of ratios.
The design also includes a one-dose transplant group and healthy adults who receive one dose. Those groups allow the study to describe immune-response outcomes across different populations and schedules through secondary outcomes. Their inclusion makes it important to keep the primary within-person question separate from the broader group comparisons. The registry record does not report numerical results for either set of immunogenicity analyses.
The study’s focus on transplant recipients is statistically relevant because the record identifies this population as immunocompromised and at increased risk of RSV lower respiratory tract disease. Evaluating immune-response measures in that population is not interchangeable with evaluating responses in healthy adults. The registry record’s group structure makes these distinct populations visible, but without reported outcome estimates it cannot show how their observed responses compared.
The record also illustrates why outcome definitions, analysis populations, and reporting completeness matter. The primary endpoint is specifically defined, but its numerical estimate and confidence interval are absent. The per protocol population description is incomplete, and methods for missing observations and multiplicity are not reported. These details shape how confidently results can be interpreted and reproduced.
Finally, safety counts can be useful for describing what was recorded, but they require careful interpretation. Counts alone do not establish causation or a comparative safety effect, particularly when groups represent different populations. The statistical value of the record lies in clarifying the questions and design; the absent immunogenicity results leave the primary statistical question unanswered in the posted information.
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 main limitation for interpreting the primary question is that the numerical primary endpoint result is not reported in the registry record. The geometric mean increase and its 95% confidence interval are specified, but without the estimate and interval it is not possible to assess either the observed change or its precision. The listed secondary immunogenicity outcomes also lack numerical results in the record available for this analysis.
The endpoint is based on serum neutralizing titers, not a reported clinical measure of RSV disease. The registry record does not report a primary disease outcome or a result linking the antibody measure to clinical protection. Therefore the endpoint’s definition should not be extended into a claim about prevention of RSV lower respiratory tract disease.
The record identifies the trial as randomized, controlled, open-label, and parallel, but does not report the randomization procedure, allocation ratio, or detailed assignment process. Masking is listed as none. The statistical analysis plan and the trial’s original sample-size justification are not reported in the registry record.
The primary analysis population is the per protocol set for humoral immunogenicity, but the available description is incomplete. The record does not explain how missing measurements, missed visits, withdrawals, or protocol deviations were handled. It also does not report whether multiplicity was controlled across the many listed outcomes and analyses.
The reported safety information is descriptive. The registry record does not give a statistical comparison of safety outcomes or establish whether individual events were considered related to vaccination. Differences between transplant recipients and healthy adults also mean that their counts should not be treated as a direct randomized comparison of population risk. These limitations constrain interpretation of the posted information without implying that unreported methods or results were absent from the full study documentation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study on the Immune Response and Safety of an RSV Vaccine When Given to Adults 18 Years of Age and Above Who Received Lung or Kidney Transplant and Are at an Increased Risk of Respiratory Syncytial Virus Lower Respiratory Tract Disease and Compared to Healthy Adults 50 Years of Age and Above — NCT05921903.
- Registry record last updated 2026-06-11; status last verified 2026-05.
- Results first posted 2025-07-16.
- 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
NCT05921903 is a completed, randomized, controlled, open-label, parallel Phase 2b study sponsored by GlaxoSmithKline. It enrolled 386 participants and evaluated the RSVPreF3 OA investigational vaccine in lung and kidney transplant recipients and healthy adults. Transplant recipients received one dose or two doses; healthy adults received one dose.
The primary endpoint was the geometric mean of within-participant ratios of RSV-A neutralizing titers after dose two versus after dose one in the two-dose transplant group. The analysis was described as using the per protocol set for humoral immunogenicity. The primary estimate and its 95% confidence interval are not reported in the registry record.
The record lists secondary RSV-A and RSV-B titer outcomes and descriptive adverse-event counts. It does not report the full statistical analysis plan, complete analysis-population criteria, or methods for missing data and multiplicity.