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 of Meningococcal ACWY Conjugate Versus Polysaccharide Vaccine in Children 2 to 10 Years of Age (NCT00329849), a randomized phase 3 study. The primary outcome is Percentage of Subjects With hSBA Seroresponse Against Serogroups A, C, W and Y One Month After Vaccination With MenACWY-CRM or MenACWY-PS.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00329849 |
| Phase | Phase 3 |
| Condition | Meningococcal Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 1500 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Novartis Vaccines |
| Results posted | Yes |
2. Clinical Question
Population
Healthy children aged 2 to 10 years. The primary analysis used the per-protocol dataset of primary vaccination: children who received the vaccine correctly, had evaluable serum samples one month after vaccination, and had no major protocol violations as defined in the analysis plan.
Intervention
One dose of meningococcal ACWY-CRM conjugate vaccine.
Comparator
One dose of meningococcal ACWY-PS polysaccharide vaccine, identified in the official title as Menomune.
Primary question
What percentage of children had an hSBA seroresponse to each of serogroups A, C, W and Y one month after vaccination? The registry record does not report the primary response percentages or their confidence intervals, so the comparative immune-response result cannot be evaluated from the reported figures.
The trial addressed immunogenicity as well as safety. Its primary endpoint was the proportion of children meeting a defined seroresponse criterion for each of four meningococcal serogroups. Secondary outcomes included hSBA response thresholds and geometric mean titers one month after vaccination, persistence of those measures at Day 181, and local and systemic reactions and axillary temperature during the 7-day period after vaccination.
The question is comparative: the study assigned children to receive one of two vaccine types and assessed outcomes after vaccination. The registry lists the study as randomized and controlled, with a parallel design and single masking. The official title describes it as observer-blind. These design features describe how the comparison was structured; they do not supply a result about which vaccine had a higher response or a different safety profile.
The primary question is specifically about a laboratory-defined immune response, not about observed meningococcal illness. The condition listed in the registry is meningococcal disease, but the primary endpoint is the percentage with an hSBA seroresponse. No clinical disease outcome result is reported in the registry record.
3. Trial Design
The registry record identifies a phase 3, randomized, controlled, parallel-group study. It lists single masking; the official title describes the study as observer-blind. The study was multicenter, and the listed enrollment is 1500. The record lists the study status as completed, with a start date of 2006-05 and primary completion of 2007-03.
Children aged 2 to 10 years were assigned to one of two vaccine groups. The MenACWY-CRM group received one dose of a quadrivalent meningococcal conjugate vaccine. The MenACWY-PS group received one dose of a quadrivalent meningococcal polysaccharide vaccine. The two groups therefore differed in the vaccine type being compared, while the listed age range and dose count were the same.
The primary endpoint was assessed one month after vaccination, at day 29. Immunogenicity was measured using serum bactericidal assay with human complement, abbreviated hSBA. The endpoint was defined separately for each of serogroups A, C, W and Y. The primary analysis population was per-protocol: the registry describes it as participants who received the vaccine correctly, provided evaluable serum samples at one month, and had no major protocol violations as defined in the analysis plan.
Secondary outcomes extended the assessment to hSBA thresholds and geometric mean titers at one month, persistence of thresholds and titers at Day 181, and local and systemic reactions and axillary temperature during the 7-day period after vaccination. These listed outcomes indicate that the study collected information on both immune-response measures and reactions after vaccination. The outcome descriptions alone do not establish how results differed between groups.
The registry record does not report the allocation sequence method, the identities of people who were masked, or further details of the conduct of the multicenter study. It also does not report the planned sample-size justification or a full statistical analysis plan. The study’s listed enrollment and design descriptors should therefore be distinguished from details of the rationale and procedures, which are not reported in the registry 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.
Before assignment: All enrolled subjects were included in the trial.
Overall Study
| Stage | MenACWY-CRM | MenACWY-PS |
|---|---|---|
| STARTED | 950 | 550 |
| COMPLETED | 944 | 546 |
| NOT COMPLETED | 6 | 4 |
Reasons for not completing this period:
| Reason | MenACWY-CRM | MenACWY-PS |
|---|---|---|
| Withdrawal by Subject | 6 | 4 |
Analysis population for the primary outcome, as defined in the registry: Analysis was done on the per-protocol (PP) dataset of primary vaccination, i.e. the subjects who received the vaccine correctly; provided evaluable serum samples at one month after vaccination; and had no major protocol violations as defined in the analysis plan.
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: Analysis was done on all enrolled subjects.
| Characteristic | Unit | MenACWY-CRM | MenACWY-PS | Total |
|---|---|---|---|---|
| Participants analysed | 950 | 550 | 1500 | |
| Age, Continuous | Years | 5.8 (SD 2.5) | 5.7 (SD 2.5) | 5.8 (SD 2.5) |
| Sex: Female, Male: Female | Participants | 482 | 288 | 770 |
| Sex: Female, Male: Male | Participants | 468 | 262 | 730 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Subjects With hSBA Seroresponse Against Serogroups A, C, W and Y One Month After Vaccination With MenACWY-CRM or MenACWY-PS, measured over 1 month after vaccination (day 29).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | Percentage of subjects |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants with an hSBA seroresponse to each of meningococcal serogroups A, C, W and Y one month after vaccination, at day 29. hSBA is a serum bactericidal assay using human complement. The endpoint turns a laboratory measurement into a binary outcome for each participant: a participant either meets the specified seroresponse definition or does not.
The definition depends on the participant’s prevaccination hSBA titer. For a participant whose prevaccination titer was less than 1:4, seroresponse required a postvaccination titer of at least 1:8. For a participant whose prevaccination titer was at least 1:4, seroresponse required an increase of at least four times the prevaccination titer. The two rules account for different starting titer categories while applying a defined response criterion.
In general, a binary percentage is useful for describing how many participants cross a prespecified threshold, and it can be compared between groups. It does not retain all the detail of the underlying titer measurements: two participants who meet the response definition may have different postvaccination titers. The registry also lists geometric mean titers as secondary outcomes, which describe the antibody titer distribution in a different way.
The primary endpoint is an immune-response measure, not a direct count of meningococcal disease cases. The registry record does not report the group-specific primary response percentages or confidence intervals. Consequently, the endpoint definition is available, but the size and precision of the observed response in either group, and the between-group comparison, are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive constraint is that the registry record describes the primary endpoint but does not report its results. It gives no response percentage for either vaccine group, no confidence intervals for those percentages, and no reported comparative estimate. The primary immune-response comparison therefore cannot be quantified from the figures in the registry record. A direction or magnitude of difference should not be inferred from the study title, endpoint description, or safety counts.
The endpoint itself is a binary classification based on hSBA titers one month after vaccination. A participant qualifies as a seroresponder under a rule that depends on the prevaccination titer. Because the endpoint is evaluated for serogroups A, C, W and Y, interpretation would require attention to the results for each serogroup rather than treating the endpoint as one undifferentiated response. Those results are not reported in the registry record.
The registry lists secondary immune outcomes at one month and at Day 181, including threshold-based response percentages and geometric mean titers. It also lists reactions and axillary temperature during the 7-day period after vaccination. These descriptions indicate the scope of measurement, but they do not provide the observed group results for those outcomes. The serious adverse event counts and other adverse event counts are reported separately and cannot substitute for missing immunogenicity results.
The safety figures show 9 participants with serious adverse events among 950 at risk in the MenACWY-CRM group and 1 among 550 at risk in the MenACWY-PS group. For other adverse events, the figures are 409 among 950 and 271 among 550, respectively. These are counts in the registry record, not evidence on their own about causation or a statistically established group difference. The registry record does not report deaths in these groups. The listed serious-event terms are accompanied by percentages, but those listings do not establish whether the events were considered related to vaccination.
In general, a confidence interval communicates uncertainty around an estimate: narrower intervals indicate greater precision, while wider intervals indicate less precision. No primary endpoint confidence intervals are reported, so the precision of the immune-response estimates cannot be assessed from the registry record. Likewise, no reported primary comparison or uncertainty measure is available to support an interpretation of the relative response.
The trial is described as randomized, which is a design feature intended to support a fair comparison between groups. Randomization does not remove the need to examine the outcome estimates, their uncertainty, the analysis population, and the handling of missing data. Since the primary results and several statistical details are not reported, the registry record supports a description of the trial question and endpoint but not a complete statistical judgment of the comparative immunogenicity findings.
9. Statistical Methods Explained
What does a percentage endpoint represent?
The primary endpoint is a percentage of participants who meet the seroresponse definition for a given serogroup. In general, a percentage summarizes a binary outcome: each participant is classified as meeting or not meeting a criterion, and the proportion meeting it is expressed as a percentage. This summary is straightforward to interpret, but it compresses the underlying measurements into a yes-or-no classification. The endpoint definition, rather than a single shared titer cutoff for everyone, determines how each participant is classified.
For this trial, the response rule uses the prevaccination hSBA titer. A starting titer less than 1:4 is evaluated using a postvaccination threshold of at least 1:8. A starting titer at least 1:4 is evaluated by whether the titer increased by at least four times. Since the rule varies with baseline status, the classification depends on both the participant’s starting and postvaccination measurements.
What does a confidence interval add?
In general, a confidence interval gives a range of values compatible with an estimate under the method used to calculate it. It conveys how much uncertainty surrounds an estimated percentage or group contrast. It is not a guarantee that the true value lies within that particular interval, and its interpretation depends on the statistical procedure and assumptions.
The primary endpoint lists a 95% confidence interval as its dispersion measure. However, the registry record does not report the primary percentages or their confidence intervals. It therefore does not allow a reader to assess the precision of the seroresponse estimates or determine whether any observed contrast is compatible with a range of materially different values.
Why are the serogroups considered separately?
The endpoint is defined for serogroups A, C, W and Y. Each serogroup represents a separate response outcome in the registry description. In general, when several related outcomes are measured, the estimates can vary across outcomes, and a single overall summary may conceal that variation. The registry record does not report a combined endpoint or a single comparison that replaces the serogroup-specific outcomes.
Multiple outcomes also raise a general multiplicity issue: conducting several statistical tests can increase the chance of at least one apparently notable result if all are interpreted without adjustment. Whether an adjustment was planned, which outcomes were considered primary for testing, and how results were to be interpreted across serogroups are not reported in the registry record. The endpoint descriptions alone do not establish that a multiplicity adjustment was or was not used.
How should the per-protocol population be understood?
The primary analysis used the per-protocol dataset of primary vaccination. The registry describes this group as participants who received the vaccine correctly, provided evaluable serum samples at one month, and had no major protocol violations as defined in the analysis plan. This specifies who was included in the primary analysis as described by the record.
In general, a per-protocol analysis focuses on participants meeting the specified conditions for the planned treatment and outcome assessment. It can be useful for examining outcomes among participants with an evaluable protocol-compliant course, but it may exclude randomized participants. A comparison based on such a subset can be affected if inclusion in that subset is related to participant characteristics or outcomes. The registry record does not report the numbers excluded from the primary analysis, the reasons for exclusion, or a corresponding analysis of all randomized participants.
The record’s description says that evaluable serum samples were required, which means the primary analysis did not include participants without an evaluable sample at the relevant assessment. The numbers and reasons for missing or unevaluable samples, and any method used to handle missing outcome data, are not reported in the registry record. No assumptions about those data can be made from the population description alone.
What do the secondary immune measures add?
The secondary outcomes include percentages meeting hSBA titer thresholds of at least 1:4 and at least 1:8, assessed one month after vaccination and at Day 181. They also include hSBA geometric mean titers at one month and persistent titers at Day 181. In general, threshold percentages describe the share of participants reaching a specified level, whereas a geometric mean titer summarizes measurements on a multiplicative scale and can reflect the distribution of titers differently. These are complementary summaries, not interchangeable definitions of the primary seroresponse outcome.
The registry record lists those outcomes but does not report their results. It also does not report the statistical models, transformations, covariate adjustments, or confidence-interval methods used for the secondary outcomes. Their names and timeframes alone do not indicate the size or precision of a group contrast.
What can the planning calculations tell readers?
In general, sample-size planning calculations illustrate how many participants might be needed under a specified effect size, allocation pattern, significance level, and statistical approximation. Such calculations are conditional on those assumptions. They are not a measure of the probability that a completed study found a real effect, and they are not “observed power.”
The planning illustration associated with the posted material uses a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It considers effects expressed as a stated fraction of the observed effect. These are planning assumptions, not a description of the trial’s own design justification. The sample-size justification used by the trial is not reported in the registry record. The planning values themselves are not reported in the registry record’s stated details, so no participant count from those illustrations can be interpreted.
Overall, the available methods description supports understanding the endpoint definition, the per-protocol population, and the listed timing of assessments. It does not provide the numerical immune-response estimates or enough detail to reconstruct the analysis. Statistical methods such as the precise comparison procedure, adjustment for multiplicity, and handling of missing outcomes are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint includes results for four serogroups: A, C, W and Y. The registry also lists secondary immune outcomes at one month and Day 181, with both threshold percentages and geometric mean titers, as well as reactions and axillary temperature during the 7-day period after vaccination. Considering multiple outcomes raises a general multiplicity question: repeated testing can increase the chance of finding an apparently notable result by chance if the results are interpreted without accounting for the number of comparisons.
The registry record does not report whether any multiplicity adjustment was planned or used, how the outcomes were ordered for statistical testing, or which secondary outcomes were intended to support formal claims. It is therefore not possible to determine from the record how multiplicity was handled. The presence of several outcomes does not itself show that an adjustment was omitted.
The primary analysis population was per-protocol and required an evaluable serum sample at one month, correct vaccine receipt, and no major protocol violations. This means the primary analysis was limited to participants meeting those stated criteria. The number of randomized participants included in that analysis, the number excluded, and the reasons for exclusion are not reported in the registry record.
The record does not report how missing or unevaluable serum results were handled, whether any imputation was used, or whether sensitivity analyses assessed alternative assumptions. In general, missing outcome data can affect an estimate if the probability of having an observed result is related to the outcome or differs between groups. Without counts and methods, the extent and direction of any such effect cannot be assessed.
The registry record also does not report an analysis population including all randomized participants as a comparison with the per-protocol analysis. It is therefore not possible to assess consistency across analysis populations. These omissions limit interpretation of the robustness of the primary result, in addition to the absence of the reported primary response estimates themselves.
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 |
|---|---|---|---|
| MenACWY-CRM | 9 | 950 | 0.9% |
| MenACWY-PS | 1 | 550 | 0.2% |
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 |
|---|---|
| MenACWY-CRM | 409 of 950 |
| MenACWY-PS | 271 of 550 |
Most frequent serious adverse event terms
| Event term | Organ system | MenACWY-CRM | MenACWY-PS |
|---|---|---|---|
| Pneumonia | Infections and infestations | 3 of 950 | 0 of 550 |
| Appendicitis | Infections and infestations | 2 of 950 | 0 of 550 |
| Lobar Pneumonia | Infections and infestations | 0 of 950 | 1 of 550 |
| Injury | Injury, poisoning and procedural complications | 1 of 950 | 0 of 550 |
| Febrile Convulsion | Nervous system disorders | 1 of 950 | 0 of 550 |
| Tonic Convulsion | Nervous system disorders | 1 of 950 | 0 of 550 |
| Asthmatic Crisis | Respiratory, thoracic and mediastinal disorders | 1 of 950 | 0 of 550 |
Most frequent non-serious adverse event terms
| Event term | Organ system | MenACWY-CRM | MenACWY-PS |
|---|---|---|---|
| Injection site pain | General disorders | 221 of 950 | 168 of 550 |
| Injection site erythema | General disorders | 166 of 950 | 71 of 550 |
| Injection site induration | General disorders | 143 of 950 | 61 of 550 |
| Headache | Nervous system disorders | 125 of 950 | 72 of 550 |
| Pyrexia | General disorders | 75 of 950 | 49 of 550 |
| Malaise | General disorders | 50 of 950 | 28 of 550 |
Serious events with the highest arm-level rate: pneumonia (0.3%), appendicitis (0.2%), lobar pneumonia (0.2%), injury (0.1%), febrile convulsion (0.1%).
The registry record reports 9 participants with serious adverse events among 950 at risk in the MenACWY-CRM group, and 1 participant with a serious adverse event among 550 at risk in the MenACWY-PS group. For other adverse events, it reports 409 participants among 950 at risk in the MenACWY-CRM group and 271 among 550 at risk in the MenACWY-PS group. These are the posted counts; they should not be read as proof that vaccination caused an event or that a group difference is statistically established.
The record lists serious adverse event terms with percentages: Pneumonia, 0.3%; Appendicitis, 0.2%; Lobar Pneumonia, 0.2%; Injury, 0.1%; Febrile Convulsion, 0.1%; and Tonic Convulsion, 0.1%. The record does not state in the listed details whether these terms are considered related to vaccination, nor does it provide the corresponding term counts or an explanation of the percentage denominators. The percentages should therefore be read as reported, without inferring a causal relationship or a comparison between groups.
Deaths are not reported in the registry record. The safety figures do not include enough detail to assess timing, severity beyond the serious-event classification, or event attribution. They should be interpreted as descriptive registry counts, not as a complete safety analysis.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized phase 3 comparison was conducted between one dose of meningococcal ACWY-CRM conjugate vaccine and one dose of meningococcal ACWY-PS polysaccharide vaccine in healthy children aged 2 to 10 years. It defines a primary immune-response endpoint based on hSBA seroresponse to four serogroups one month after vaccination and lists additional immune and safety outcomes.
It does not, however, report the primary seroresponse percentages, confidence intervals, or a numerical comparison between groups. The registry record therefore does not establish from the reported figures how the groups differed in the primary endpoint, how precise either group estimate was, or whether any contrast was compatible with a wide range of values. No direction or magnitude of the primary immunogenicity result can be inferred from the endpoint definition alone.
The listed serious and other adverse event counts describe the reported safety data, but they do not establish causality or statistical evidence of a difference. The record does not report deaths, details of event attribution, or the statistical analysis of safety outcomes. The listed serious-event terms and percentages also do not substitute for a full comparative safety analysis.
In general, a randomized design is intended to support comparison by assigning participants to groups, but interpretation still depends on the outcome estimates, uncertainty, analysis population, missing-data handling, and analysis methods. Here, the registry record identifies a per-protocol primary population, while details about exclusions, missing outcomes, and alternative populations are not reported.
The study’s endpoint is a laboratory measure of immune response. It should not be treated as a reported measure of clinical meningococcal disease prevention. The registry lists meningococcal disease as a condition but does not report a clinical disease result. The information in the record supports describing what was measured and how some safety counts were recorded; it does not support a treatment recommendation or a conclusion that one vaccine performed better or worse.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of how an endpoint definition shapes a comparison. Its primary outcome was not simply a fixed postvaccination titer threshold for every child: the seroresponse rule depended on the prevaccination titer. Understanding that rule is essential to interpreting any eventual response percentage, because the classification combines baseline and postvaccination measurements.
The endpoint also separates results by serogroup. A comparison across serogroups can reveal whether response estimates are consistent or vary, but it creates several related outcomes that require careful interpretation. The registry record lists outcomes for serogroups A, C, W and Y and further measures at one month and Day 181. It does not report how multiplicity was handled, making this a useful reminder that a long outcome list is not, by itself, a statistical testing plan.
The record illustrates the distinction between an outcome definition and an outcome result. The primary endpoint, analysis population and assessment time are described, but the primary percentages and confidence intervals are not reported in the registry record. Without estimates and their uncertainty, readers cannot evaluate the size or precision of the immune-response comparison. This distinction matters whenever trial records contain detailed methods but incomplete results.
The per-protocol population is another important interpretive feature. It focuses the primary analysis on participants who received the vaccine correctly, had evaluable one-month serum samples, and had no major protocol violations. That definition explains the intended analysis subset, but counts of excluded participants and missing-data methods are not reported. Statistical interpretation must account for both who was analyzed and who was not.
Finally, the safety counts provide descriptive context while underscoring the difference between observing events and attributing them to an intervention. Counts and listed event terms alone do not establish causation or a comparative effect. Taken together, the record makes clear why a sound statistical reading requires endpoint definitions, estimates, uncertainty, analysis-population details and transparent handling of multiple outcomes.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation for interpreting efficacy-related results is that the registry record does not report the primary endpoint percentages or confidence intervals. Although it defines seroresponse and identifies the assessment at one month, it does not provide the numerical results for either vaccine group or a direct comparison. This prevents an assessment of the observed difference and its precision.
The primary analysis was per-protocol and required correct vaccine receipt, an evaluable one-month serum sample and no major protocol violations. The registry record does not report how many participants met these conditions, how many were excluded, or why participants were excluded. Without those details, the reader cannot judge how the analyzed group relates to the randomized study population.
Information about missing data is also limited. The record does not report the number of missing or unevaluable samples, the reasons for missingness, an imputation method, or sensitivity analyses. It does not report whether results were also analyzed in a population including all randomized participants. These omissions limit assessment of how dependent the primary comparison may be on the per-protocol analysis.
The registry lists numerous immune and safety outcomes, but multiplicity procedures and the statistical methods for the secondary outcomes are not reported. The allocation sequence method, masking details beyond the registry classification and observer-blind title, and the trial’s sample-size justification are also not reported. The sample-size planning illustration is not the trial’s own design rationale.
Safety counts are available, but the record does not report deaths, event attribution, or details sufficient to evaluate each event term by group. These limits do not imply that the study lacked relevant methods or analyses; they mean those details and primary results are not reported in the registry record. Interpretation should remain confined to the design description and the specific posted counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Immunogenicity of Meningococcal ACWY Conjugate Versus Polysaccharide Vaccine in Children 2 to 10 Years of Age — NCT00329849.
- Registry record last updated 2018-10-09; status last verified 2018-09.
- Results first posted 2013-11-05.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes a completed phase 3, randomized, controlled, parallel-group, multicenter study of meningococcal ACWY-CRM conjugate vaccine versus meningococcal ACWY-PS polysaccharide vaccine in healthy children aged 2 to 10 years. It lists single masking and an enrollment of 1500. The study start is recorded as 2006-05 and primary completion as 2007-03.
Each group received one dose. The primary endpoint was the percentage with hSBA seroresponse to serogroups A, C, W and Y one month after vaccination, assessed in a per-protocol population. Secondary outcomes included hSBA thresholds and geometric mean titers at one month and Day 181, plus reactions and axillary temperature during the 7-day period after vaccination.
The registry record reports serious and other adverse event counts, but does not report primary endpoint results, deaths, or several analysis details. The comparative immune-response result therefore cannot be evaluated from the reported figures.