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 Open Label Extension Study to Assess the Safety and Long-Term Immunogenicity of ARCT-021 (NCT04728347), a non-randomized phase 2 study. The primary outcome is Number of Participants With Solicited Local and Systemic Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04728347 |
| Phase | Phase 2 |
| Condition | SARS-CoV-2 |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 65 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Arcturus Therapeutics, Inc. |
| Results posted | Yes |
2. Clinical Question
The study asks about short-term solicited adverse events after ARCT-021 and longer-term safety and immunogenicity follow-up in healthy adults who participated in the parent study. It is an open-label extension, not a randomized comparison. Participants were assigned to receive a single injection or to receive no injection and continue safety follow-up; the registry record does not establish that these groups are comparable.
Population
Healthy adults who participated in Study ARCT-021-01. The record describes Cohort 1a as participants who received study vaccine in ARCT-021-02 only, and Cohort 1b as participants who received study vaccine in both ARCT-021-01 and ARCT-021-02. Cohort 2 is divided into younger adults and older adults, but the age boundaries are not reported in the registry record.
Intervention
A single injection of ARCT-021 on Day 1 for participants in the intervention group. The record does not report a dose amount in the information available for this analysis.
Comparator
Long-term follow-up without intervention for participants in the follow-up group. Because allocation was non-randomized and masking was absent, this is not a like-for-like control comparison.
Primary question
How many participants had solicited local or systemic adverse events through Day 7 after vaccine administration? The registry record defines the event categories but does not report the primary endpoint results.
Secondary questions concern serum neutralizing and binding antibodies, including geometric mean titers or concentrations, fold rises, and seroconversion among ARCT-021-naïve participants in Cohort 1a. The record lists these outcomes but does not report their results. Thus, the available information describes the questions the trial set out to address, not evidence that resolves them.
3. Trial Design
This is a Phase 2a, open-label extension study with non-randomized allocation and no masking. The record describes a parallel model. Participants could receive a single dose of ARCT-021 or receive no intervention and be followed for safety. The study enrolled healthy adults who had participated in Study ARCT-021-01, so this was not a trial recruiting an unrelated population for a new randomized comparison.
The registry lists enrollment of 65. It records a start date of 2021-01-04, a primary completion date of 2021-12-28, and a status of terminated. The reason for termination is not reported in the registry record. The planned follow-up for participants was up to 365 days, although the primary solicited-event timeframe was through Day 7 after vaccine administration.
The record distinguishes the cohorts in its safety population descriptions. Cohort 1a includes participants who received study vaccine in ARCT-021-02 only. Cohort 1b includes participants who received study vaccine in both ARCT-021-01 and ARCT-021-02. The adverse-event results also list Cohort 2: Younger Adults and Cohort 2: Older Adults. The record does not explain the age cutoffs or provide further detail about the allocation process in the information.
Because the study was open-label and non-randomized, participants and study personnel were not masked, and group membership was not determined by random assignment. Differences between groups could therefore reflect differences in who entered each group as well as any effects of receiving the injection. The follow-up-only group can provide context, but it should not be treated as a randomized control. The registry record does not report a statistical analysis plan, a sample-size justification, or 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.
Overall Study
| Stage | Cohort 1a | Cohort 1b | Cohort 2 Younger Adults | Cohort 2: Older Adults |
|---|---|---|---|---|
| STARTED | 12 | 12 | 25 | 16 |
| Received Study Drug in This Study | 12 | 12 | 0 | 0 |
| COMPLETED | 12 | 12 | 24 | 16 |
| NOT COMPLETED | 0 | 0 | 1 | 0 |
Reasons for not completing this period:
| Reason | Cohort 1a | Cohort 1b | Cohort 2 Younger Adults | Cohort 2: Older Adults |
|---|---|---|---|---|
| Sponsor decision | 0 | 0 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Safety population for Cohort 1a, which included all participants who received Study vaccine in ARCT-021-02 only, and in the Longitudinal Safety population for Cohort 1b, which included all participants who received Study vaccine in ARCT- 021-01 and ARCT-021-02. As pre-specified, data is reported for Cohort 1 only.
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: Data presented for all enrolled participants. As pre-specified, baseline characteristics are presented per sub-cohort (younger and older adults) for Cohort 2.
| Characteristic | Unit | Cohort 1a | Cohort 1b | Cohort 2: Younger Adults | Cohort 2: Older Adults | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 12 | 12 | 25 | 16 | 65 | |
| Age, Continuous | years | 45.1 (SD 14.99) | 48.3 (SD 16.17) | 39.7 (SD 8.34) | 63.7 (SD 4.13) | 48.2 (SD 14.28) |
| Sex: Female, Male: Female | Participants | 3 | 2 | 9 | 4 | 18 |
| Sex: Female, Male: Male | Participants | 9 | 10 | 16 | 12 | 47 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 12 | 12 | 25 | 16 | 65 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 1 | 0 | 1 |
| Race (NIH/OMB): Asian | Participants | 12 | 11 | 22 | 16 | 61 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 0 | 1 | 1 | 0 | 2 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 1 | 0 | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Solicited Local and Systemic Adverse Events, measured over Up to Day 7 (7 days after vaccine administration).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with solicited local and systemic adverse events through Day 7, described as 7 days after vaccine administration. Local events include pain, tenderness, erythema or swelling at the injection site. Systemic events include fever, fatigue, headache, chills, nausea, vomiting, diarrhoea, myalgia and arthralgia. The endpoint is a participant count, rather than a measure of event severity or duration.
Solicited events are specified in advance and actively assessed during a defined period. In general, this approach can make collection of expected symptoms more consistent than relying only on spontaneous reports. It also defines a particular safety question: whether participants experienced any of the listed local or systemic events during the stated timeframe. It does not, by itself, describe all possible adverse events or establish whether an event was caused by the intervention.
The registry record says that summaries of serious and other non-serious adverse events, regardless of causality, are located in the Reported Adverse Events module. Those summaries are separate from the primary solicited-event endpoint. The adverse-event counts listed in the record do not report how many participants had the solicited local or systemic events defined above. Consequently, the primary endpoint result is not reported in the registry record. The listed endpoint definition explains what was intended to be counted, but it cannot substitute for the missing result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The available results are limited to adverse-event counts by cohort. The record lists serious adverse events among 12 participants at risk in Cohort 1a, with 0 affected; among 12 in Cohort 1b, with 1 affected; among 25 in Cohort 2: Younger Adults, with 0 affected; and among 16 in Cohort 2: Older Adults, with 0 affected. Deaths are listed as 0 in each cohort. For other non-serious adverse events, the record lists 3 affected among 12 at risk in Cohort 1a, 1 among 12 in Cohort 1b, 3 among 25 in Cohort 2: Younger Adults, and 0 among 16 in Cohort 2: Older Adults.
These counts describe what the registry reports for the safety groups; they do not constitute a randomized treatment comparison. In particular, the allocation was non-randomized, and the cohorts have different descriptions and potentially different exposure histories. The registry record does not report adjusted comparisons or uncertainty estimates for these counts. A difference between observed counts across cohorts would therefore not establish that the intervention caused a difference in risk.
The record identifies Ischaemic stroke as a serious adverse-event term and gives 8.3%. It does not give further detail in the material available for this analysis about the event's timing, clinical course, relationship to study intervention, or cohort attribution. The serious adverse-event summaries are reported regardless of causality, so the presence of a term in this list should not be read as a judgment that the intervention caused it.
The primary endpoint itself is not reported in the registry record. Although the endpoint specifies solicited symptoms through Day 7, the posted cohort counts for serious and other non-serious adverse events are not a substitute for counts of the defined solicited local and systemic events. The listed secondary immunogenicity outcomes likewise have no results. Thus, the record supports a description of reported safety counts and the study's intended questions, but not an estimate of the primary endpoint or the antibody responses.
Counts are useful for making the scale of reported observations concrete, but without the relevant endpoint data and accompanying uncertainty, they do not show how precisely any underlying event frequency is estimated. The study's non-randomized, open-label structure further limits causal interpretation. No claim about benefit or lack of benefit follows from these safety summaries, and the record does not report enough outcome information to evaluate the study's immunogenicity questions.
9. Statistical Methods Explained
The registry describes the primary endpoint as a count of participants with an event. This is a binary outcome at the participant level for the specified event definition: a participant either meets the endpoint definition during the stated period or does not. A count communicates how many participants met that definition within the listed group. It does not capture how often a participant had repeated symptoms, how severe they were, or how long they lasted, unless those features are separately reported.
What does a participant count tell us?
In general, a count should be interpreted alongside the number of participants assessed. The record gives participants at risk for its serious and other non-serious adverse-event summaries. Those denominators allow the reader to understand the size of each reported group, but they do not supply the missing primary solicited-event counts. Counts in small groups can change substantially with a small change in the number of participants affected. A count alone also does not indicate whether differences between groups are more than would be expected from sampling variability.
A proportion is often useful for comparing event occurrence across groups, but no new proportions or comparisons are calculated. The record gives one percentage, 8.3%, for the listed serious adverse-event term Ischaemic stroke. The remaining safety results are stated as participant counts at risk and affected. No confidence intervals are reported with these summaries in the information available for this analysis.
Why does study allocation matter?
Random allocation is intended to make groups comparable, on average, with respect to factors that could influence outcomes. This study was non-randomized, and the record does not describe a procedure that would make the cohorts exchangeable. Differences in previous vaccine exposure, participant characteristics, follow-up, or other factors could be associated with both group membership and outcomes. These are general concerns for non-randomized comparisons; the record does not establish that any particular factor explains the reported counts.
Open-label conduct means the treatment assignment was not masked. In general, awareness of assignment can affect reporting, assessment, or follow-up, especially for outcomes that depend on symptom reports. The listed solicited endpoint comprises symptoms that are assessed after injection, while the registry record does not report how outcome assessment was conducted or whether any safeguards were used. Without a masked assessment and a randomized allocation, comparisons should be interpreted as descriptive rather than causal.
What can uncertainty estimates add?
In general, a confidence interval gives a range of values compatible with the observed data under a specified statistical method. It can show how imprecise an estimate is, rather than presenting a point estimate as if it were exact. The registry record does not report confidence intervals or other uncertainty estimates for the safety counts. Nor does it report a statistical analysis plan specifying the methods for estimating or comparing these outcomes. A reader therefore cannot assess the precision of a treatment contrast from the posted counts alone.
For counts or proportions, the appropriate uncertainty method depends on the design and the outcome definition. More complex designs may require adjustment for factors such as repeated observations or clustering. General statistical methods cannot repair limitations in the underlying allocation or replace unreported outcome data. No adjusted or recalculated treatment effect is reported.
How should planning calculations be read?
Sample-size calculations are planning illustrations, not results observed in participants. The stated assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Such calculations depend on their assumptions and are not evidence that a study had a particular probability of detecting an effect after it was conducted. They should not be described as observed power.
The registry record does not report the trial's own sample-size justification or a statistical plan establishing that these assumptions were used to design this extension study. It also does not report a primary endpoint effect estimate from which to assess the planning illustration in this analysis. The enrollment of 65 is a record of enrollment, not a justification for the chosen enrollment or proof of adequate precision.
Why do the antibody outcomes require separate interpretation?
The registry lists geometric mean titers for serum neutralizing antibodies, geometric mean fold rise in neutralizing antibody titers, seroconversion among ARCT-021-naïve participants in Cohort 1a, geometric mean concentration of binding antibodies, fold rise in binding antibody titers, and seroconversion for binding antibodies. These measures address antibody response, not adverse-event frequency. Geometric means are generally used for measurements whose distributions are skewed, often after analysis on a logarithmic scale; fold rise describes change relative to a baseline measurement. Seroconversion applies a specified response definition. The registry record does not report the relevant estimates, definitions beyond the outcome titles, or analysis methods. These general explanations therefore do not imply any particular antibody result.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 9 outcome measures and 0 analyses. Several secondary outcomes concern distinct antibody measures, including neutralizing and binding antibodies, fold rises, and seroconversion. When multiple outcomes are examined, the chance of at least one apparently notable result can increase. General approaches to handling multiplicity include identifying a primary outcome in advance, adjusting decision thresholds, or treating secondary results as exploratory. The registry record does not report whether any multiplicity procedure was planned or applied.
The primary safety endpoint is defined, but its results are not reported in the registry record. The listed antibody outcomes also lack reported results in the information available for this analysis. No analysis plan, interim analysis details, or statistical methods for these outcomes are reported. It is therefore not possible to determine how endpoint prioritization, repeated testing, or interim looks were handled.
The record describes a safety population for Cohort 1a and a longitudinal safety population for Cohort 1b, with each definition linked to prior or current study vaccine receipt. It does not report full analysis-population definitions for every outcome in the information. Missing-data methods, reasons for missing observations, and the amount of missing data are not reported in the registry record. The reported participants at risk in the adverse-event summaries indicate the stated denominators for those summaries, but do not explain whether any participants were excluded from other analyses or why.
These omissions limit assessment of whether outcome-specific populations were consistent with the stated questions and whether missingness could affect interpretation. No assumptions about missing outcomes or unreported analysis choices should be inferred from the cohort summaries.
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 |
|---|---|---|---|
| Cohort 1a | 0 | 12 | 0.0% |
| Cohort 1b | 1 | 12 | 8.3% |
| Cohort 2: Younger Adults | 0 | 25 | 0.0% |
| Cohort 2: Older Adults | 0 | 16 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cohort 1a | 0 of 12 |
| Cohort 1b | 0 of 12 |
| Cohort 2: Younger Adults | 0 of 25 |
| Cohort 2: Older Adults | 0 of 16 |
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 |
|---|---|
| Cohort 1a | 3 of 12 |
| Cohort 1b | 1 of 12 |
| Cohort 2: Younger Adults | 3 of 25 |
| Cohort 2: Older Adults | 0 of 16 |
Most frequent serious adverse event terms
| Event term | Organ system | Cohort 1a | Cohort 1b | Cohort 2: Younger Adults | Cohort 2: Older Adults |
|---|---|---|---|---|---|
| Ischaemic stroke | Nervous system disorders | 0 of 12 | 1 of 12 | 0 of 25 | 0 of 16 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cohort 1a | Cohort 1b | Cohort 2: Younger Adults | Cohort 2: Older Adults |
|---|---|---|---|---|---|
| Blood creatine phosphokinase increased | Investigations | 1 of 12 | 0 of 12 | 0 of 25 | 0 of 16 |
| Decreased appetite | Metabolism and nutrition disorders | 1 of 12 | 0 of 12 | 0 of 25 | 0 of 16 |
| Rhinitis allergic | Respiratory, thoracic and mediastinal disorders | 1 of 12 | 0 of 12 | 0 of 25 | 0 of 16 |
| Vessel puncture site bruise | General disorders | 0 of 12 | 1 of 12 | 0 of 25 | 0 of 16 |
| Lip dry | Gastrointestinal disorders | 0 of 12 | 0 of 12 | 1 of 25 | 0 of 16 |
| Ligament sprain | Injury, poisoning and procedural complications | 0 of 12 | 0 of 12 | 1 of 25 | 0 of 16 |
| Tendon rupture | Injury, poisoning and procedural complications | 0 of 12 | 0 of 12 | 1 of 25 | 0 of 16 |
| Rotator cuff syndrome | Musculoskeletal and connective tissue disorders | 0 of 12 | 0 of 12 | 1 of 25 | 0 of 16 |
| Headache | Nervous system disorders | 0 of 12 | 0 of 12 | 1 of 25 | 0 of 16 |
Serious events with the highest arm-level rate: ischaemic stroke (8.3%).
The serious adverse-event summary lists 0 affected among 12 participants at risk in Cohort 1a, 1 among 12 in Cohort 1b, 0 among 25 in Cohort 2: Younger Adults, and 0 among 16 in Cohort 2: Older Adults. The deaths count is 0 for each listed cohort. For other non-serious adverse events, the corresponding affected counts are 3, 1, 3 and 0, with the at-risk counts of 12, 12, 25 and 16 respectively.
The registry separately identifies Ischaemic stroke at 8.3% among the top serious-event terms. The record does not report further details about the event's timing, participant course, or relationship to ARCT-021. The adverse-event module includes serious and other non-serious events regardless of causality. An event being recorded therefore does not establish that the study intervention caused it.
These adverse-event summaries should not be mistaken for the primary endpoint. That endpoint concerns solicited local and systemic symptoms through Day 7, while these summaries concern serious and other non-serious adverse events. The registry record does not report the primary solicited-event counts. The cohort counts are descriptive and do not support a causal comparison, particularly given non-randomized allocation and the different cohort descriptions.
12. What the Result Does, and Does Not, Mean
The record establishes that this was an open-label, non-randomized extension study in healthy adults who had participated in the parent study. Participants could receive a single injection of ARCT-021 or continue follow-up without intervention. The registry lists safety counts by cohort, including the number at risk and the number affected for serious and other non-serious adverse events, as well as deaths. Those values describe the posted safety summaries, not a randomized estimate of treatment effect.
The primary question is not answered by the reported counts. It concerns solicited local and systemic adverse events through Day 7, but the registry record does not report the number of participants meeting that endpoint. Likewise, the listed outcomes for neutralizing and binding antibodies do not have results reported in the information available for this analysis. The study title and outcome definitions indicate the intended scope; they do not provide evidence about the results.
Non-randomized groups may differ for reasons other than intervention, and no masking was used. Consequently, even a visible difference in reported event counts would not by itself show that ARCT-021 caused the difference. The safety counts also do not establish the absence of other events or the absence of risk; they are limited to the events and reporting summarized in the record.
The record lists Ischaemic stroke at 8.3% among serious-event terms. That entry should be read as a reported safety observation, not as proof of causation. The registry information does not provide the details needed to assess the event's clinical context or attribution.
Overall, the posted information allows a reader to identify the study design, endpoint definitions and selected adverse-event counts. It does not allow a complete assessment of the primary safety endpoint, antibody outcomes, statistical precision, or causal effects. These limits apply to interpretation of the registry record; they are not conclusions about unreported results.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of why design and reporting context matter when reading clinical-trial safety data. The study combines an extension setting with non-randomized allocation and no masking. The cohorts include participants with different exposure histories, as described in the registry. Those features mean that cohort counts can be useful descriptions but should not be treated as a fair randomized contrast.
It also illustrates the distinction between an endpoint definition and an endpoint result. The registry gives a detailed list of solicited local and systemic symptoms and a Day 7 timeframe. Yet the corresponding participant counts are not reported in the information available for this analysis. Conversely, serious and other non-serious adverse-event counts are present, but they address a different safety summary. Keeping those outcome categories separate prevents one set of results from being used as a substitute for another.
The study's secondary questions cover several antibody measures, each addressing a different aspect of immunogenicity. Their presence in the registry signals a broad set of intended outcomes, but without estimates, uncertainty intervals, and a reported plan for multiplicity, their results cannot be evaluated. This is a reminder that a list of endpoints does not reveal whether, or how, they were analyzed.
Finally, a registry status of terminated and an enrollment figure are elements of study conduct, not statistical findings about safety or immunogenicity. The reason for termination and the study's own sample-size justification are not reported in the registry record. Careful interpretation therefore rests on separating what the record describes from what it does not report, and on avoiding causal claims that the design and available outcomes cannot support.
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 registry record leaves important details unavailable for interpreting this particular study. Although it reports the study as terminated, it does not report why it was terminated. It lists enrollment of 65, but the reason for the enrollment target and any sample-size justification are not reported. The statistical analysis plan, interim analyses, and methods for handling multiplicity are also not reported in the registry record.
The primary solicited local and systemic adverse-event endpoint is defined with a timeframe and event list, but its results are not reported in the information available for this analysis. The registry's serious and other non-serious adverse-event counts do not fill that gap because they are different summaries. Results for the listed antibody outcomes are likewise not reported, preventing interpretation of the study's immunogenicity questions.
The safety population definitions distinguish Cohort 1a and Cohort 1b by study vaccine receipt, but the record excerpt does not fully describe analysis populations for all outcomes. The age limits for the younger and older adult groups are not reported. Missing-data amounts, reasons for missingness, and methods for addressing missing observations are not reported in the registry record.
Non-randomized allocation and open-label conduct are central limitations for interpreting comparisons. The record does not report enough detail to assess whether groups were adjusted for baseline differences or how event assessments were conducted. The serious-event entry for Ischaemic stroke lacks further context in the information, including attribution and clinical course. These limitations constrain interpretation of the posted record and should not be filled by assumptions about the protocol or the underlying data.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Open Label Extension Study to Assess the Safety and Long-Term Immunogenicity of ARCT-021 — NCT04728347.
- Registry record last updated 2024-12-30; status last verified 2024-12.
- Results first posted 2024-12-30.
- 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 record describes a Phase 2a, open-label extension study of ARCT-021 in healthy adults who participated in Study ARCT-021-01. Allocation was non-randomized, masking was absent, and the listed model was parallel. Participants were to receive a single injection or no intervention, with follow-up for up to 365 days. The study enrolled 65 and is listed as terminated; the reason for termination is not reported in the registry record.
The primary endpoint is the number of participants with solicited local and systemic adverse events through Day 7. The registry defines the symptoms but does not report the endpoint results in the information. It does report serious and other non-serious adverse-event counts by cohort, including deaths, and lists Ischaemic stroke at 8.3% among serious-event terms. These summaries are descriptive and do not establish causation. Results for the listed antibody outcomes, missing-data methods, and the statistical analysis plan are not reported in the registry record.