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 Safety and Immunogenicity Study to Assess TDV, a Live Attenuated Tetravalent Vaccine for Prevention of Dengue Fever (NCT01224639), a randomized phase 1 study. The primary outcome is Number of Participants With Local Injection Site Reaction by Severity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01224639 |
| Phase | Phase 1 |
| Condition | Dengue Fever |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 96 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Inviragen Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Healthy adults. The registry record describes the safety population as randomized participants who received at least one study-vaccine dose and had post-dosing safety data. Reported enrollment was 96.
Intervention
TDV, a live attenuated tetravalent dengue vaccine candidate, given at a low or high dose by subcutaneous or intradermal injection. Vaccinations were scheduled on Days 0 and 90.
Comparator
Placebo was given by the same route, subcutaneously or intradermally. The randomized groups therefore covered dose level, route, and placebo comparisons.
Primary question
How many participants experienced local injection-site reactions, classified by severity, within 14 days after either vaccination? The registry also lists immune-response and vaccine-viremia outcomes, but does not report results for the primary endpoint.
This is a phase I safety and immunogenicity study in healthy adults, not a clinical-outcome trial evaluating prevention of dengue illness. Its primary question concerns reactions at the injection site after vaccination. The registry describes solicited reactions recorded in participant diaries, including pain, redness, swelling, and itching, with severity categories defined separately for these symptoms.
The vaccine was assessed at two dose levels and by two injection routes, with placebo comparators by route. This structure could describe safety and immune-response measures across the dose and route groups. However, the registry record does not provide a reported primary-endpoint result or a statistical comparison for that question. The posted safety counts concern serious and other adverse events; they should not be mistaken for the severity-specific primary endpoint counts.
3. Trial Design
The registry identifies this as a randomized, triple-masked, parallel-group phase I study. It was sponsored by Inviragen Inc. Enrollment was 96. The study started on 2010-10-11, had primary completion on 2011-06-09, and is listed as completed. The registry record does not report further details about how randomization or masking were implemented.
TDV was studied at low and high dose, using either subcutaneous (SC) or intradermal (ID) administration. Each dose level and route had a placebo group receiving phosphate buffered saline by the corresponding route. Vaccination was scheduled on Days 0 and 90. The registry describes the SC dose volume as 0.5 mL and the ID volume as 0.1 mL. It lists different component dose levels for the low- and high-dose vaccine groups, but does not provide a statistical comparison across those components in the posted results.
The primary outcome was the number of participants with local injection-site reactions by severity, assessed within 14 days after either vaccination. The registry gives the assessment windows as Day 14 after the first vaccination and Day 104 after the second. Secondary outcomes concerned neutralizing antibody titers and seroconversion after each vaccination, durability of immune response, and vaccine viremia, including its occurrence, duration, and titers. Immune response was assessed up to 9 months after the first vaccination, according to the study summary.
These design features describe what the trial set out to assess, not what the results establish. The registry record lists 12 outcome measures and 0 analyses. It does not report a trial-specific statistical analysis plan, the rationale for the enrollment target, or details of interim analyses.
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: Healthy male and female participants were enrolled in 1 of the 8 treatment groups: Low Dose Subcutaneous:TDV, Low Dose Subcutaneous: Placebo, Low Dose Intradermal:TDV, Low Dose Intradermal:Placebo, High Dose Subcutaneous:TDV, High Dose Subcutaneous:Placebo, High Dose Intradermal:TDV, High Dose Intradermal:Placebo.
Only the first 6 of 8 groups are shown.
Overall Study
| Stage | Low Dose Subcutaneous: TDV | Low Dose Subcutaneous: Placebo | Low Dose Intradermal: TDV | Low Dose Intradermal: Placebo | High Dose Subcutaneous: TDV | High Dose Subcutaneous: Placebo |
|---|---|---|---|---|---|---|
| STARTED | 19 | 5 | 21 | 3 | 21 | 4 |
| COMPLETED | 19 | 5 | 21 | 3 | 19 | 4 |
| NOT COMPLETED | 0 | 0 | 0 | 0 | 2 | 0 |
Reasons for not completing this period:
| Reason | Low Dose Subcutaneous: TDV | Low Dose Subcutaneous: Placebo | Low Dose Intradermal: TDV | Low Dose Intradermal: Placebo | High Dose Subcutaneous: TDV | High Dose Subcutaneous: Placebo |
|---|---|---|---|---|---|---|
| Withdrawal by Subject | 0 | 0 | 0 | 0 | 2 | 0 |
| Adverse Event | 0 | 0 | 0 | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: The safety population included all randomized participants who received at least one dose of study vaccine and for whom post-dosing safety data was obtained.
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: The safety population included all randomized participants who received at least one dose of study vaccine and for whom post-dosing safety data was obtained.
Only the first 6 of 9 groups are shown.
| Characteristic | Unit | Low Dose Subcutaneous: TDV | Low Dose Subcutaneous: Placebo | Low Dose Intradermal: TDV | Low Dose Intradermal: Placebo | High Dose Subcutaneous: TDV | High Dose Subcutaneous: Placebo |
|---|---|---|---|---|---|---|---|
| Participants analysed | 19 | 5 | 21 | 3 | 21 | 4 | |
| Age, Customized: Less than (<) 18 years | participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Customized: Greater than or equal to (>=) 18 and <65 years | participants | 19 | 5 | 21 | 3 | 21 | 4 |
| Age, Customized: >=65 years | participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 14 | 4 | 11 | 2 | 17 | 3 |
| Sex: Female, Male: Male | Participants | 5 | 1 | 10 | 1 | 4 | 1 |
| Race/Ethnicity, Customized: White | participants | 2 | 0 | 4 | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Other | participants | 17 | 5 | 17 | 3 | 21 | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Local Injection Site Reaction by Severity, measured over Within 14 days after either of the vaccination given on Day 1 or 90 (Day 14 for first vaccination, Day 104 for second vaccination).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with a local injection-site reaction, separated by severity. Solicited reactions were recorded in participant diaries. The registry names pain, redness, swelling, and itching, and describes symptom-specific severity categories. Pain severity reflects whether pain interferes with daily activity or leads to use of pain medication; redness and swelling are categorized by size; itching is categorized by its extent or intensity.
This endpoint is used to describe short-term local tolerability after vaccination. Counting participants with reactions can communicate how often an event was observed in each study group, while severity categories distinguish less troublesome reactions from those described as more severe. The registry specifies an observation window within 14 days after each vaccination, allowing the endpoint to focus on reactions occurring soon after dosing.
The registry record does not report the primary-endpoint counts by symptom, severity, route, dose, or vaccination. It therefore does not support a quantitative comparison of local reaction frequency or severity. The safety-population definition is also important: it includes randomized participants who received at least one dose and had post-dosing safety data. It is not described as including every randomized participant regardless of dosing or follow-up.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted registry information describes the design and gives group-level safety counts for serious and other adverse events. It does not give the primary endpoint results: counts of local injection-site reactions by severity within the specified follow-up windows. Consequently, the main question named for the trial cannot be answered quantitatively from the registry results. There are no reported primary-endpoint estimates or uncertainty intervals to interpret.
The safety summary reports serious adverse events in 1 participant in the low-dose intradermal placebo group and 1 participant in the high-dose subcutaneous TDV group. It reports 0 serious adverse events in each of the other listed groups. These are observed counts in the posted group summaries, not evidence by themselves of a causal relationship to vaccine or placebo. The registry record does not report whether the serious events were considered related to study treatment.
For other adverse events, the posted counts vary across groups: 12 of 19 in the low-dose subcutaneous TDV group, 5 of 5 in its placebo group, 13 of 21 in the low-dose intradermal TDV group, 3 of 3 in its placebo group, 15 of 21 in the high-dose subcutaneous TDV group, 2 of 4 in its placebo group, 13 of 18 in the high-dose intradermal TDV group, and 3 of 5 in its placebo group. These counts describe participants affected in the registry’s safety summary. They are not a substitute for the local reaction endpoint, and they do not establish that an event was caused by the assigned intervention.
Group sizes differ, and several placebo groups contain few participants. Raw counts therefore should not be compared as though each group had the same opportunity to observe events. Even when a proportion can be read from a group count, estimates from small groups are imprecise. The record does not provide confidence intervals or adjusted comparisons for these safety counts.
More broadly, this is a phase I study in healthy adults. Its purpose and outcomes focus on safety and immune response rather than clinical dengue outcomes. The registry lists immunogenicity and vaccine-viremia measures, but does not report their results in the information available for this interpretation. No conclusion about protection against dengue, or about the comparative safety of routes or doses, follows from the posted information alone.
9. Statistical Methods Explained
Statistical interpretation begins with the distinction between a planned endpoint and a reported result. The registry names the number of participants with local injection-site reactions by severity as the primary endpoint. It also defines an observation period within 14 days after either vaccination. But it does not report the corresponding counts. Without those results, there is no primary-endpoint estimate to compare across groups and no precision measure to assess.
What does a count measure?
A participant count records how many people in a group had an event, rather than how many event episodes occurred. The distinction matters when one participant might have more than one episode or symptom. The primary outcome’s title refers to participants with reactions, while the registry’s description also names multiple reaction types and severity categories. The record does not provide the detailed result breakdown needed to tell how these categories were tabulated in practice.
In general, a confidence interval expresses the statistical uncertainty around an estimated quantity. A narrow interval indicates greater precision, while a wide interval indicates less precision. Confidence intervals are especially useful alongside event counts because the same observed count can be compatible with a range of underlying event frequencies. The registry record does not report confidence intervals for the local reaction endpoint or the posted adverse-event counts.
Why does group size matter?
In general, the precision of an event-frequency estimate depends in part on how many participants were observed and how many events occurred. Small groups can yield unstable estimates: one additional event can make a relatively large difference to the observed count or proportion. That issue is relevant to the placebo groups in this trial, whose reported group sizes range from 3 to 5. The registry reports different numbers at risk across the eight safety groups, so comparisons of raw counts alone are not like-for-like.
Randomization is intended, in general, to make comparison groups comparable in expectation, but it does not ensure that small groups are balanced on every characteristic. The registry identifies the study as randomized but does not report the allocation procedure, concealment method, or baseline characteristics. Those details are not reported in the registry record, so the degree of balance cannot be assessed from this information.
What can be inferred from adverse-event summaries?
The registry lists participants at risk and participants affected for serious and other adverse events. These are descriptive safety summaries. A count in one group is not, by itself, a treatment effect estimate: it does not account for uncertainty, establish a difference between groups, or show that treatment caused the event. A causal comparison would require an appropriate analysis and enough detail about outcome definitions, follow-up, and analysis populations. Such an analysis is not reported in the registry record.
For general statistical reasoning, uncertainty is particularly substantial when event counts are sparse. A zero observed count does not prove that the underlying event frequency is zero. Likewise, a nonzero count does not establish an excess risk without a relevant comparison and an assessment of uncertainty. Here, no inferential comparison of serious or other adverse events is reported.
What do the planning illustrations represent?
The posted sample-size illustrations are planning calculations, not observed trial findings and not observed power. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. Such illustrations ask, in general, what sample size might be needed under those assumptions to detect a chosen effect. They do not show that the trial was designed with those assumptions, nor do they establish that the observed trial had adequate power. The registry does not report the trial’s own sample-size justification.
Because no primary-endpoint effect is reported, an illustration based on an observed effect cannot be interpreted as a planning estimate for the local reaction endpoint from this record. A sample-size calculation also cannot repair missing outcome reporting: it describes a hypothetical design requirement, not the result or precision of the completed study.
The registry lists 0 analyses. It does not report a detailed statistical analysis plan, modeling choices, adjustment for multiple testing, missing-data methods, or sensitivity analyses. Therefore, no unreported method should be assumed to have been used. The statistical interpretation should remain descriptive and limited to the stated design and posted counts.
10. Multiplicity, Missing Data and Analysis Populations
The study has several outcomes and several group dimensions: dose level, injection route, and placebo status. The registry lists 12 outcome measures, including local reactions, antibody titers, seroconversion, immune-response durability, and vaccine viremia. Considering multiple outcomes or multiple group comparisons can increase the chance of finding an apparently notable result by chance. In general, a prespecified analysis plan can state which comparisons are primary and how multiplicity will be handled. Such details are not reported in the registry record.
The primary endpoint itself includes several reaction types and severity categories, and assessments after two vaccinations. The registry record does not give a multiplicity strategy for those categories or time points. It also lists 0 analyses, so there are no reported inferential comparisons or adjustment procedures to evaluate. No claim about statistical significance or family-wise error control can be made from the posted information.
Missing-data handling is not reported in the registry record. The stated safety population includes randomized participants who received at least one dose and for whom post-dosing safety data was obtained. This definition excludes people without the required post-dosing safety information from that population, but the record does not report how many were excluded, how missing diary entries were handled, or whether any imputation or sensitivity analysis was used.
The record also does not report the analysis populations used for immunogenicity or vaccine-viremia outcomes. It is therefore not possible to determine from this information whether those outcomes used the same population as the safety endpoint, or how missing measurements affected their denominators. These omissions limit reproducibility and make it difficult to judge whether the reported summaries reflect all participants intended for each assessment.
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 |
|---|---|---|---|
| Low Dose Subcutaneous: TDV | 0 | 19 | 0.0% |
| Low Dose Subcutaneous: Placebo | 0 | 5 | 0.0% |
| Low Dose Intradermal: TDV | 0 | 21 | 0.0% |
| Low Dose Intradermal: Placebo | 1 | 3 | 33.3% |
| High Dose Subcutaneous: TDV | 1 | 21 | 4.8% |
| High Dose Subcutaneous: Placebo | 0 | 4 | 0.0% |
| High Dose Intradermal: TDV | 0 | 18 | 0.0% |
| High Dose Intradermal: Placebo | 0 | 5 | 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 |
|---|---|
| Low Dose Subcutaneous: TDV | 12 of 19 |
| Low Dose Subcutaneous: Placebo | 5 of 5 |
| Low Dose Intradermal: TDV | 13 of 21 |
| Low Dose Intradermal: Placebo | 3 of 3 |
| High Dose Subcutaneous: TDV | 15 of 21 |
| High Dose Subcutaneous: Placebo | 2 of 4 |
Most frequent serious adverse event terms
| Event term | Organ system | Low Dose Subcutaneous: TDV | Low Dose Subcutaneous: Placebo | Low Dose Intradermal: TDV | Low Dose Intradermal: Placebo | High Dose Subcutaneous: TDV | High Dose Subcutaneous: Placebo |
|---|---|---|---|---|---|---|---|
| Suicide attempt | Psychiatric disorders | 0 of 19 | 0 of 5 | 0 of 21 | 1 of 3 | 0 of 21 | 0 of 4 |
| Ankle fracture | Injury, poisoning and procedural complications | 0 of 19 | 0 of 5 | 0 of 21 | 0 of 3 | 1 of 21 | 0 of 4 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Low Dose Subcutaneous: TDV | Low Dose Subcutaneous: Placebo | Low Dose Intradermal: TDV | Low Dose Intradermal: Placebo | High Dose Subcutaneous: TDV | High Dose Subcutaneous: Placebo |
|---|---|---|---|---|---|---|---|
| NASOPHARYNGITIS | Infections and infestations | 3 of 19 | 2 of 5 | 4 of 21 | 0 of 3 | 5 of 21 | 0 of 4 |
| HEADACHE | Nervous system disorders | 1 of 19 | 1 of 5 | 4 of 21 | 1 of 3 | 6 of 21 | 1 of 4 |
| ANAEMIA | Blood and lymphatic system disorders | 3 of 19 | 1 of 5 | 0 of 21 | 0 of 3 | 0 of 21 | 1 of 4 |
| COUGH | Respiratory, thoracic and mediastinal disorders | 1 of 19 | 0 of 5 | 2 of 21 | 0 of 3 | 2 of 21 | 0 of 4 |
| VACCINATION SITE HAEMATOMA | General disorders | 0 of 19 | 0 of 5 | 3 of 21 | 0 of 3 | 1 of 21 | 0 of 4 |
| ASYMPTOMATIC BACTERIURIA | Infections and infestations | 0 of 19 | 0 of 5 | 0 of 21 | 1 of 3 | 2 of 21 | 1 of 4 |
| URINARY TRACT INFECTION | Infections and infestations | 2 of 19 | 0 of 5 | 2 of 21 | 0 of 3 | 0 of 21 | 0 of 4 |
| RASH | Skin and subcutaneous tissue disorders | 1 of 19 | 0 of 5 | 0 of 21 | 0 of 3 | 3 of 21 | 0 of 4 |
| NAUSEA | Gastrointestinal disorders | 1 of 19 | 0 of 5 | 0 of 21 | 0 of 3 | 2 of 21 | 0 of 4 |
| GASTROENTERITIS | Infections and infestations | 0 of 19 | 0 of 5 | 1 of 21 | 0 of 3 | 2 of 21 | 0 of 4 |
Serious events with the highest arm-level rate: suicide attempt (33.3%), ankle fracture (4.8%).
The safety summary separates serious adverse events from other adverse events and gives, for each group, the number at risk and the number affected. Serious adverse events were reported for 1 participant in the low-dose intradermal placebo group and 1 participant in the high-dose subcutaneous TDV group; the other listed groups each report 0. For other adverse events, the affected counts are 12 of 19, 5 of 5, 13 of 21, 3 of 3, 15 of 21, 2 of 4, 13 of 18, and 3 of 5, in the order of the groups described in the interpretation.
The registry lists suicide attempt at 33.3% and ankle fracture at 4.8% among the top serious terms. The denominator and context for these percentages are not reported in the registry record, so they should not be interpreted as percentages of a particular trial group or as evidence of treatment causation. The record does not report whether serious events were considered related to study treatment. Deaths are not reported in the registry record.
These figures are descriptive. Small group sizes and the absence of uncertainty intervals mean that differences in counts should not be treated as precise comparative estimates. The serious-event counts also do not report the primary local-reaction endpoint.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the trial was a randomized, triple-masked phase I study of TDV at low and high doses, administered by subcutaneous or intradermal injection, with route-matched placebo groups. It describes a planned safety assessment focused on local injection-site reactions within 14 days after each vaccination, as well as secondary measures of immune response and vaccine viremia.
The posted results support a limited descriptive account of serious and other adverse events by group. They do not include the primary endpoint counts by reaction type or severity, and they do not report inferential comparisons, confidence intervals, or a detailed statistical analysis plan. The serious-event summaries therefore do not establish whether one dose, route, or treatment group differed from another, and they cannot establish that an event was caused by study treatment.
This record does not show whether the vaccine prevents dengue illness. The listed outcomes concern safety, antibody responses, seroconversion, response durability, and vaccine viremia, rather than clinical protection against dengue. Although the study summary says immune response was assessed up to 9 months after the first vaccination, the relevant results are not reported in the registry record.
More generally, absence of a reported result is not evidence that no event occurred or that groups were equivalent. Likewise, observed safety counts do not alone demonstrate a benefit or harm. The study’s phase I setting and healthy-adult population also limit what can be inferred beyond the population and outcomes described. The most defensible reading is that the registry documents the design and some adverse-event counts, while leaving the primary endpoint and several planned immune-response results unreported.
13. Why This Trial Matters Statistically
This study illustrates why registry design details and outcome results need to be read separately. The record describes a multifactorial safety design, with two dose levels, two injection routes, and placebo groups. This structure can be useful for organizing early-phase assessments, but comparisons across several small groups can be imprecise. Group-specific counts are therefore more informative when accompanied by denominators, clear outcome definitions, and uncertainty estimates.
It also illustrates the difference between a named primary endpoint and a reported primary result. The registry defines local injection-site reactions by symptom and severity and specifies an assessment window after each vaccination. Yet the primary-endpoint counts are not reported in the registry information. Without them, readers cannot quantify the endpoint, examine severity patterns, or assess precision. A detailed endpoint definition cannot replace the results needed to answer the study question.
The adverse-event summaries show another statistical distinction: descriptive counts are not causal comparisons. A serious event reported in a vaccine or placebo group does not by itself establish attribution, and a zero count does not prove absence of risk. Small groups make such summaries especially difficult to interpret comparatively. The record does not give uncertainty intervals or adjusted analyses that could clarify the range of plausible differences.
Finally, the posted planning illustrations should not be confused with the trial’s original design rationale or with observed power. The registry does not report the trial’s own sample-size justification. This matters because readers need to distinguish calculations based on an observed effect from prospective planning decisions and from actual evidence. Clear reporting of the planned analysis, populations, missing-data handling, and endpoint results would make the statistical interpretation more complete.
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.
A key limitation is that the registry record does not report the primary endpoint results, despite giving a detailed definition of local reaction symptoms, severity categories, and follow-up windows. The severity-specific counts and denominators are unavailable, preventing assessment of the primary safety question. The record also does not report the immune-response or vaccine-viremia results named among the secondary outcomes.
The safety summaries provide counts by group but no confidence intervals, statistical comparisons, or treatment-relatedness assessments. The registry does not report detailed event definitions for the other adverse-event category, nor does it clarify the context or denominator for the listed serious-event term percentages. Deaths are not reported in the registry record; this should not be read as a confirmed absence of deaths.
Several placebo groups are small, and the group sizes differ. Estimates from small groups are inherently imprecise, while raw counts are difficult to compare when the numbers at risk vary. The record does not provide baseline characteristics to assess balance across randomized groups, or details of allocation and masking procedures.
Methods that could affect interpretation are also not reported: the full statistical analysis plan, multiplicity handling, missing-data procedures, and analysis populations for secondary outcomes. The safety population is defined, but the record does not explain the handling of incomplete diaries or missing assessments. These reporting gaps limit both independent reproduction of analyses and the strength of conclusions that can be drawn from the posted results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Immunogenicity Study to Assess TDV, a Live Attenuated Tetravalent Vaccine for Prevention of Dengue Fever — NCT01224639.
- Registry record last updated 2018-06-19; status last verified 2018-06.
- Results first posted 2017-02-27.
- 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
NCT01224639 is a completed phase I randomized, triple-masked, parallel-group study sponsored by Inviragen Inc. It enrolled 96 healthy adults and assessed low- and high-dose TDV given subcutaneously or intradermally, with placebo groups using the same routes. Vaccinations were scheduled on Days 0 and 90.
The primary outcome was the number of participants with local injection-site reactions by severity within 14 days after either vaccination. Secondary outcomes included antibody titers, seroconversion, immune-response durability, and vaccine viremia. The registry record reports group counts for serious and other adverse events, but does not report the primary-endpoint results, secondary outcome results, detailed statistical analysis plan, or trial-specific sample-size justification.