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 Study to Evaluate Safety, Tolerability & Immunogenicity of BNT162b2 in Immunocompromised Participants ≥2 Years (NCT04895982), a na phase 2 study. The primary outcome is Geometric Mean Titers (GMTs) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV 2) Neutralizing Titers at 1 Month After Vaccination 3 in Participants Aged >=2 to <5 Years Without Serological or Virological Evidence of Past SARS-CoV-2 Infection.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04895982 |
| Phase | Phase 2 |
| Condition | SARS-CoV-2 Infection, COVID19 |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 124 |
| Arms in the primary outcome | n/a |
| Lead sponsor | BioNTech SE |
| Results posted | Yes |
2. Clinical Question
Population
Immunocompromised participants aged 2 years and older were enrolled. The primary endpoint specifically concerns participants aged ≥2 to <5 years who had no serological or virological evidence of past SARS-CoV-2 infection and no medical history of COVID-19. Its analysis population is the Dose 3 Evaluable Immunogenicity population, defined by vaccination and sample timing requirements.
Intervention
Participants received BNT162b2 by intramuscular injection. The study is described as a 4 dose study. The registry record does not describe a randomized assignment to different interventions.
Comparator
There is no concurrent control group in the registered single-group design. The allocation entry is NA, and the registry’s own caution says the arms are not a like-for-like control comparison. The primary question is therefore not a randomized comparison between BNT162b2 and another treatment or control.
Primary question
The registered primary measure is the geometric mean titer of SARS-CoV-2 neutralizing antibodies 1 month after vaccination 3 among the specified participants aged ≥2 to <5 years. It describes an antibody response in an eligible analysis population at a stated time point. The numeric primary outcome result is not reported in the registry record, so the magnitude and precision of that response cannot be described from the recorded information.
3. Trial Design
This is a phase 2b, open-label, single-group study of BNT162b2 in immunocompromised participants aged 2 years and older. The registry record reports an enrollment of 124 participants and describes the enrolled population as 7 adults and 117 children. Adults are defined in the record as participants 18 years of age or older. Enrollment was based on conditions that make participants immunocompromised.
The study is described as a 4 dose study. Participants were to be followed for 6 months after dose 4, and each participant was projected to be in the study for approximately 15 months. The planned study locations were the United States, Brazil, Germany, and Mexico. The intervention is BNT162b2, administered by intramuscular injection.
The registry lists no allocation scheme and describes the study model as single group, with no masking. This means the registered design does not establish a randomized, masked comparison against a concurrent control. Its findings are principally descriptive of participants who received the study intervention under the study conditions. The registry explicitly cautions that the arms are not a like-for-like control comparison.
The record gives a start date of 2021-10-15, a primary completion date of 2023-07-23, and a completed status. It lists 56 outcome measures and zero analysis records. A sample-size justification, details of interim analyses, and a statistical analysis plan are not reported in the registry record. The primary endpoint is narrower than the full enrolled population: it concerns eligible participants aged ≥2 to <5 years after vaccination 3, rather than every age group and every participant enrolled.
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: A total of 124 participants were enrolled in this study.
Only the first 6 of 12 groups are shown.
Overall Study
| Stage | (Greater Than or Equal to (>=) 2 to Less Than (<) 5 Years With Immunomodulatory Therapy | >=2 to <5 Years With Solid Organ Transplant | >=2 to <5 Years With Stem Cell Transplant | >=5 to <12 Years With Immunomodulatory Therapy | >=5 to <12 Years With Solid Organ Transplant | >=5 to <12 Years With Stem Cell Transplant |
|---|---|---|---|---|---|---|
| STARTED | 9 | 15 | 13 | 19 | 24 | 22 |
| Dose 1 | 9 | 15 | 13 | 19 | 24 | 22 |
| Dose 2 | 9 | 15 | 12 | 19 | 24 | 22 |
| Dose 3 | 9 | 15 | 11 | 17 | 24 | 22 |
| Dose 4 | 7 | 13 | 6 | 14 | 20 | 17 |
| COMPLETED | 7 | 12 | 6 | 16 | 20 | 18 |
| NOT COMPLETED | 2 | 3 | 7 | 3 | 4 | 4 |
Reasons for not completing this period:
| Reason | (Greater Than or Equal to (>=) 2 to Less Than (<) 5 Years With Immunomodulatory Therapy | >=2 to <5 Years With Solid Organ Transplant | >=2 to <5 Years With Stem Cell Transplant | >=5 to <12 Years With Immunomodulatory Therapy | >=5 to <12 Years With Solid Organ Transplant | >=5 to <12 Years With Stem Cell Transplant |
|---|---|---|---|---|---|---|
| Withdrawal by Subject | 0 | 0 | 0 | 0 | 0 | 1 |
| Withdrawal by parent/guardian | 2 | 3 | 3 | 1 | 3 | 2 |
| Other | 0 | 0 | 1 | 1 | 0 | 0 |
| Protocol Violation | 0 | 0 | 1 | 1 | 1 | 0 |
| Lost to Follow-up | 0 | 0 | 1 | 0 | 0 | 1 |
| Refused further study procedures | 0 | 0 | 1 | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Dose 3 EIP= all participants who received 3 doses of vaccine with Dose 2 and Dose 3 within predefined window, had at least 1 valid \& determinate immunogenicity result from sample collected within appropriate window (28 to 42 days, inclusive, after Dose 3); had no other important protocol deviations as determined by clinician. No participants qualified for Dose 3 EIP without prior evidence of past SARS-CoV-2 infection up to 1 month after dose 3 in '\>=2 to \<5 years with stem cell transplant' arm.
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: Safety population included all participants who received at least 1 dose of study intervention. To avoid risk of identification of participant, any baseline measure data is not disclosed for reporting arm including (\>=18 Years with Non-Small Cell Lung Cancer, \>= 18 Years with Haemodialysis) and baseline measure data other than age is not disclosed for reporting arm (\>=12 to \<18 Years with Solid Organ Transplant) and reported the participant under category- Not Disclosed
Only the first 6 of 13 groups are shown.
| Characteristic | Unit | >=2 to <5 Years With Immunomodulatory Therapy | >=2 to <5 Years With Solid Organ Transplant | >=2 to <5 Years With Stem Cell Transplant | >=5 to <12 Years With Immunomodulatory Therapy | >=5 to <12 Years With Solid Organ Transplant | >=5 to <12 Years With Stem Cell Transplant |
|---|---|---|---|---|---|---|---|
| Participants analysed | 9 | 15 | 13 | 19 | 24 | 22 | |
| Age, Customized: Children (2-11 years) | Participants | 9 | 15 | 13 | 19 | 24 | 22 |
| Age, Customized: Adolescents (12-17 years) | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Customized: Adults (18-64 years) | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Customized: From 65-84 years | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Customized: Not disclosed | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Sex/Gender, Customized: Female | Participants | 4 | 8 | 3 | 12 | 9 | 5 |
| Sex/Gender, Customized: Male | Participants | 5 | 7 | 10 | 7 | 15 | 17 |
| Sex/Gender, Customized: Not disclosed | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Hispanic or Latino | Participants | 1 | 1 | 4 | 6 | 2 | 2 |
| Race/Ethnicity, Customized: Not Hispanic or Latino | Participants | 8 | 14 | 9 | 13 | 22 | 19 |
| Race/Ethnicity, Customized: Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 | 1 |
| Race/Ethnicity, Customized: Not Disclosed | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race/Ethnicity, Customized: Asian | Participants | 0 | 1 | 0 | 0 | 1 | 0 |
| Race/Ethnicity, Customized: Black or African American | Participants | 0 | 2 | 0 | 1 | 0 | 3 |
| Race/Ethnicity, Customized: White | Participants | 9 | 11 | 12 | 17 | 21 | 19 |
| Race/Ethnicity, Customized: More than one race | Participants | 0 | 0 | 1 | 0 | 1 | 0 |
| Race/Ethnicity, Customized: Unknown or Not Reported | Participants | 0 | 1 | 0 | 1 | 1 | 0 |
| Race/Ethnicity, Customized: Not disclosed | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Geometric Mean Titers (GMTs) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV 2) Neutralizing Titers at 1 Month After Vaccination 3 in Participants Aged >=2 to <5 Years Without Serological or Virological Evidence of Past SARS-CoV-2 Infection, measured over 1 Month after Vaccination 3.
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Titers |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the geometric mean titer (GMT) of SARS-CoV-2 neutralizing antibodies 1 month after vaccination 3 in participants aged ≥2 to <5 years without serological or virological evidence of past SARS-CoV-2 infection. A GMT summarizes antibody titers using their logarithms: the titers are transformed, averaged on the logarithmic scale, and then transformed back. This approach is commonly used for antibody measures because titers can be distributed unevenly on the original scale. In general, the GMT describes a typical level on a multiplicative scale; it is not a measure of the proportion of participants who experienced a clinical outcome.
The registry says that the GMT and its 2-sided confidence interval were calculated by exponentiating the mean of the logarithms of titers and the corresponding confidence limits based on Student’s t distribution. Results below the assay’s lower limit of quantification were set to 0.5*LLOQ for this analysis. The record specifies that the analysis used the Dose 3 Evaluable Immunogenicity population and sets out requirements for valid, determinate samples within the stated window after dose 3.
Neutralizing-antibody titers are a laboratory immunogenicity measure. They do not, by themselves, directly report a clinical outcome such as infection or disease. The numerical GMT and its confidence interval are not reported in the registry record, so the endpoint’s observed level and statistical precision cannot be assessed from the recorded results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary endpoint is defined clearly enough to identify its measure, timing, age group, and analysis population. It is a laboratory measure of neutralizing-antibody titers 1 month after vaccination 3, restricted to participants aged ≥2 to <5 years without evidence of past infection under the registry’s stated criteria. However, the numeric primary result is not reported in the registry record. Without a GMT estimate and its confidence interval, there is no basis in the recorded information to describe the observed antibody level, its precision, or how variable the estimate may be.
The registry lists 56 outcome measures and zero analysis records. These entries do not substitute for a numerical endpoint result or a detailed statistical report. The record’s description of the calculation method explains how the primary measure was intended to be summarized, but a method description alone does not reveal the result. The sample-size assumptions describe a planning illustration, not observed power and not necessarily the trial’s original design justification.
The single-group, open-label design also determines what comparisons can be made. There is no randomized concurrent control group in the registered design. The registry cautions that the arms are not a like-for-like control comparison. Accordingly, the registered study cannot supply a randomized estimate of the difference between BNT162b2 and a control intervention. Any changes over time or differences among listed groups would require appropriate data and analysis and should not be interpreted as controlled treatment effects simply because they appear as separate categories.
The safety information is also descriptive. The record lists group-specific numbers at risk and affected for serious and other adverse events, along with serious-event terms and percentages. Those entries can describe reported events in the listed groups, but the registry record does not provide the context needed to establish comparative risk or attribute an event to the intervention. The recorded death count is 0 in each listed group; that observation should be read within the groups and reporting described, not as proof that an uncommon event cannot occur.
Overall, the registry record documents the study design, endpoint definition, and some safety summaries, but does not report the primary numerical immunogenicity result. Statistical interpretation should therefore stay with what is recorded: a planned antibody summary and descriptive safety information, without a reported primary estimate or randomized comparison.
9. Statistical Methods Explained
Statistical methods are useful only when their assumptions, data, and target question are understood together. The registry record describes a geometric mean and confidence interval for the primary immunogenicity endpoint, but does not report the numerical result. The explanations below are general statistical context applied to the method description in the record.
Why use a geometric mean for titers?
General explanation: antibody titers often vary across a wide scale, and their distribution may be more suitable for analysis after taking logarithms. A geometric mean is calculated by averaging log-transformed observations and transforming the average back to the original scale. It therefore represents a central value on a multiplicative scale. It is not the same as an ordinary arithmetic average and should not be described as a percentage of participants responding.
The registry states that the GMT was calculated by exponentiating the mean logarithm of titers. The confidence limits were formed on the log scale using Student’s t distribution and then exponentiated. This back-transformation keeps the summary and its interval on the original titer scale. A confidence interval describes statistical uncertainty around an estimate under the analysis assumptions; it does not show the full spread of individual participants’ values. Since the GMT and confidence interval are not reported in the registry record, their location and width cannot be interpreted.
How are results below the assay limit handled?
The lower limit of quantification (LLOQ) is the assay threshold below which a result cannot be quantified reliably under the laboratory method. General explanation: replacing below-limit results with a specified value allows them to be included in a numerical summary, but this is an analytical convention rather than a measurement of the exact underlying titer. The registry says results below LLOQ were set to 0.5*LLOQ. The count of results treated this way and any sensitivity analyses using alternative handling are not reported in the registry record.
What does the analysis population require?
The primary analysis population is described as the Dose 3 Evaluable Immunogenicity population. The record defines it using receipt of 3 vaccine doses, dose timing within a predefined window, at least 1 valid and determinate immunogenicity result from a sample collected within the appropriate window of 28 to 42 days, inclusive, after dose 3, and no other important protocol deviations. This is a restricted population based on vaccination, specimen availability, timing, and protocol adherence. Such a definition may help focus the endpoint analysis on participants with usable measurements under the specified conditions, but it also means the endpoint is not automatically a summary of every enrolled participant.
The endpoint’s infection-history criteria further narrow the population: participants needed to have no evidence of past infection under the stated serological and virological criteria and no medical history of COVID-19. The number of participants meeting each eligibility condition, and the numbers excluded for specific reasons, are not reported in the registry record. Those details would help readers understand how the analyzed participants relate to the enrolled group.
Why does the design matter?
General explanation: randomization can make treatment groups more comparable, on average, with respect to measured and unmeasured characteristics. A single-group study does not use randomized allocation to form a concurrent control group. Open-label means the study is not masked; knowledge of treatment assignment can affect reporting, assessment, or other study conduct, depending on the outcome and procedures. These are design considerations, not evidence that any particular bias occurred in this study. The registry explicitly states that its arms are not a like-for-like control comparison, so those group listings should not be treated as randomized comparative evidence.
What can planning assumptions tell readers?
The record describes a sample-size planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. It specifies that time-to-event calculations concern total events, while other planning calculations concern participants per arm. These are planning assumptions for an illustration, not a description of the single-group study’s own design. Any sample sizes from that type of exercise are planning illustrations, never observed power. A sample-size justification for the trial itself is not reported in the registry record.
In general, a sample-size calculation depends on the target effect, variability or event rate, significance level, allocation, and analysis method. If a planning calculation borrows an observed effect, the result depends on that estimate and may not represent the effect a future study should be designed to detect. No sample-size values from the illustration are stated in the registry entries described for this analysis, so no such values or design implications can be inferred.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 56 outcome measures and zero analysis records, but a complete statistical analysis plan is not reported in the registry record. A multiplicity plan is also not reported in the registry record. This matters because evaluating many outcomes or time points can increase the chance of observing an apparently notable result by chance if analyses are treated as independent confirmatory tests. General explanation: multiplicity methods can control or otherwise address that concern, but the appropriate approach depends on which outcomes are confirmatory, how they are related, and what claims are intended. The record does not establish how such issues were handled.
The primary endpoint description does provide a defined analysis population and a stated method for calculating the GMT and its confidence interval. It does not report the number analyzed, the numerical GMT, or the confidence limits. The record also does not report the number of participants with missing or unusable samples, reasons for missingness, or any imputation or sensitivity-analysis strategy. Missing-data handling is therefore not reported in the registry record.
The defined Dose 3 Evaluable Immunogenicity population requires a valid, determinate result within the sample window and specified vaccination timing, so participants without qualifying data would not meet that analysis definition. The effect of this restriction on the endpoint estimate cannot be assessed from the registry information. It is also not reported whether another analysis population was used for a complementary analysis of the primary endpoint.
The record provides no detail on interim analyses, stopping rules, or adjustments linked to repeated looks at the data. These items are not reported in the registry record and should not be presumed to have occurred or not occurred. A result-level statistical interpretation would require the actual estimate, its uncertainty interval, the analyzed population size, and the prespecified approach to outcome selection, multiplicity, and missing data.
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 |
|---|---|---|---|
| >=2 to <5 Years With Immunomodulatory Therapy | 0 | 9 | 0.0% |
| >=2 to <5 Years With Solid Organ Transplant | 8 | 15 | 53.3% |
| >=2 to <5 Years With Stem Cell Transplant | 3 | 13 | 23.1% |
| >=5 to <12 Years With Immunomodulatory Therapy | 3 | 19 | 15.8% |
| >=5 to <12 Years With Solid Organ Transplant | 5 | 24 | 20.8% |
| >=5 to <12 Years With Stem Cell Transplant | 3 | 22 | 13.6% |
| >=12 to <18 Years With Immunomodulatory Therapy | 0 | 7 | 0.0% |
| >=12 to <18 Years With Solid Organ Transplant | 0 | 1 | 0.0% |
| >=12 to <18 Years With Stem Cell Transplant | 0 | 7 | 0.0% |
| >=18 Years With Immunomodulatory Therapy | 1 | 5 | 20.0% |
| >=18 Years With Non-Small Cell Lung Cancer | 0 | 1 | 0.0% |
| >= 18 Years With Haemodialysis | 1 | 1 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| >=2 to <5 Years With Immunomodulatory Therapy | 0 of 9 |
| >=2 to <5 Years With Solid Organ Transplant | 0 of 15 |
| >=2 to <5 Years With Stem Cell Transplant | 0 of 13 |
| >=5 to <12 Years With Immunomodulatory Therapy | 0 of 19 |
| >=5 to <12 Years With Solid Organ Transplant | 0 of 24 |
| >=5 to <12 Years With Stem Cell Transplant | 0 of 22 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| >=2 to <5 Years With Immunomodulatory Therapy | 8 of 9 |
| >=2 to <5 Years With Solid Organ Transplant | 13 of 15 |
| >=2 to <5 Years With Stem Cell Transplant | 10 of 13 |
| >=5 to <12 Years With Immunomodulatory Therapy | 18 of 19 |
| >=5 to <12 Years With Solid Organ Transplant | 23 of 24 |
| >=5 to <12 Years With Stem Cell Transplant | 22 of 22 |
Most frequent serious adverse event terms
| Event term | Organ system | >=2 to <5 Years With Immunomodulatory Therapy | >=2 to <5 Years With Solid Organ Transplant | >=2 to <5 Years With Stem Cell Transplant | >=5 to <12 Years With Immunomodulatory Therapy | >=5 to <12 Years With Solid Organ Transplant | >=5 to <12 Years With Stem Cell Transplant |
|---|---|---|---|---|---|---|---|
| Gastroenteritis | Infections and infestations | 0 of 9 | 2 of 15 | 0 of 13 | 0 of 19 | 1 of 24 | 0 of 22 |
| Urinary tract infection | Infections and infestations | 0 of 9 | 2 of 15 | 0 of 13 | 1 of 19 | 0 of 24 | 0 of 22 |
| Anaemia | Blood and lymphatic system disorders | 0 of 9 | 0 of 15 | 0 of 13 | 1 of 19 | 0 of 24 | 0 of 22 |
| Epilepsy | Nervous system disorders | 0 of 9 | 0 of 15 | 0 of 13 | 0 of 19 | 1 of 24 | 0 of 22 |
| Pulmonary vein stenosis | Respiratory, thoracic and mediastinal disorders | 0 of 9 | 1 of 15 | 0 of 13 | 0 of 19 | 0 of 24 | 0 of 22 |
| Dental caries | Gastrointestinal disorders | 0 of 9 | 0 of 15 | 1 of 13 | 0 of 19 | 0 of 24 | 0 of 22 |
| Diarrhoea | Gastrointestinal disorders | 0 of 9 | 0 of 15 | 0 of 13 | 0 of 19 | 1 of 24 | 0 of 22 |
| Intestinal obstruction | Gastrointestinal disorders | 0 of 9 | 0 of 15 | 0 of 13 | 1 of 19 | 0 of 24 | 0 of 22 |
| Acute kidney injury | Renal and urinary disorders | 0 of 9 | 0 of 15 | 0 of 13 | 0 of 19 | 1 of 24 | 0 of 22 |
| Dermatomyositis | Skin and subcutaneous tissue disorders | 0 of 9 | 0 of 15 | 0 of 13 | 1 of 19 | 0 of 24 | 0 of 22 |
Most frequent non-serious adverse event terms
| Event term | Organ system | >=2 to <5 Years With Immunomodulatory Therapy | >=2 to <5 Years With Solid Organ Transplant | >=2 to <5 Years With Stem Cell Transplant | >=5 to <12 Years With Immunomodulatory Therapy | >=5 to <12 Years With Solid Organ Transplant | >=5 to <12 Years With Stem Cell Transplant |
|---|---|---|---|---|---|---|---|
| Injection site pain (PAIN AT INJECTION SITE) | General disorders | 4 of 9 | 3 of 15 | 4 of 13 | 16 of 19 | 18 of 24 | 19 of 22 |
| Fatigue (FATIGUE) | General disorders | 3 of 9 | 3 of 15 | 3 of 13 | 14 of 19 | 17 of 24 | 14 of 22 |
| Headache (HEADACHE) | Nervous system disorders | 0 of 9 | 1 of 15 | 0 of 13 | 11 of 19 | 11 of 24 | 9 of 22 |
| Erythema (REDNESS) | General disorders | 3 of 9 | 3 of 15 | 0 of 13 | 7 of 19 | 5 of 24 | 6 of 22 |
| Swelling (SWELLING) | General disorders | 1 of 9 | 1 of 15 | 1 of 13 | 5 of 19 | 4 of 24 | 8 of 22 |
| Diarrhoea (DIARRHEA) | Gastrointestinal disorders | 2 of 9 | 3 of 15 | 2 of 13 | 5 of 19 | 5 of 24 | 2 of 22 |
| Myalgia (NEW OR WORSENED MUSCLE PAIN) | Musculoskeletal and connective tissue disorders | 1 of 9 | 1 of 15 | 0 of 13 | 6 of 19 | 8 of 24 | 3 of 22 |
| Chills (CHILLS) | General disorders | 2 of 9 | 1 of 15 | 1 of 13 | 7 of 19 | 3 of 24 | 5 of 22 |
| Vomiting (VOMITING) | Gastrointestinal disorders | 1 of 9 | 3 of 15 | 4 of 13 | 2 of 19 | 4 of 24 | 1 of 22 |
| Pyrexia (FEVER) | General disorders | 2 of 9 | 1 of 15 | 2 of 13 | 2 of 19 | 2 of 24 | 5 of 22 |
Serious events with the highest arm-level rate: melaena (100.0%), azotaemia (100.0%), gangrene (100.0%), renal colic (20.0%), gastroenteritis (13.3%).
The safety record lists groups by age range and immunocompromising condition, with numbers at risk and numbers affected for serious and other adverse events. These are descriptive counts within the listed groups. They should be read in their stated group context, rather than treated as a comparison between randomized treatment arms. The registry’s caution is that the arms are not a like-for-like control comparison.
The listed serious-event terms include Melaena, Azotaemia, and Gangrene at 100.0%; Renal colic at 20.0%; and Gastroenteritis and Urinary tract infection at 13.3%. The registry record does not report the denominators or event counts associated with these term-specific percentages in the information available for this interpretation. A percentage alone does not communicate how many events occurred or how stable the estimate is, particularly in small groups.
The death count is 0 in each listed group. This is a description of the reported record, not evidence that the risk of death or another serious event is absent. The safety entries also do not, on their own, establish that BNT162b2 caused an event. Causal attribution and comparative safety require context beyond these descriptive group summaries, including a suitable comparison and fuller details of event definitions, follow-up, and ascertainment.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a phase 2b, open-label, single-group study assessed BNT162b2 in immunocompromised participants aged 2 years and older. It specifies a primary immunogenicity question about neutralizing-antibody GMT 1 month after vaccination 3 in a narrowly defined group aged ≥2 to <5 years without evidence or history of past COVID-19. The record also describes the calculation method and the Dose 3 Evaluable Immunogenicity population.
What the recorded information does not establish is the observed primary endpoint result. The numeric GMT and its confidence interval are not reported in the registry record. Consequently, readers cannot assess the estimated titer level or its statistical precision from the record. A method for estimating an outcome is not itself evidence of what the observed estimate was.
The design also limits interpretation. Because the study is single group and open label, and the registry warns that arms are not a like-for-like control comparison, the information cannot be treated as a randomized comparison of BNT162b2 with a control. Descriptive safety entries can identify reported events in listed groups, but they do not show comparative risks or establish causation. The absence of a recorded death in each listed group does not demonstrate that serious outcomes are impossible.
More generally, antibody titers are laboratory measures. They characterize an immune response as defined by the assay and analysis; they are not themselves direct counts of infections, hospitalizations, or other clinical outcomes. Any connection between a titer measure and a clinical outcome would require evidence beyond the measure’s name or calculation method. No such clinical-effect conclusion should be inferred from the endpoint definition alone.
The most defensible reading is therefore limited: the registry documents the intended immunogenicity measure, its analysis criteria, study design, and descriptive adverse-event information, but does not report the numerical primary result. The record does not support claims about the size or precision of the primary antibody response, comparative effectiveness, or comparative safety.
13. Why This Trial Matters Statistically
This study raises statistical issues that are important when interpreting immunogenicity research in a population defined by immunocompromising conditions. The enrolled population spans children and adults, while the registered primary endpoint focuses specifically on participants aged ≥2 to <5 years who meet additional infection-history and evaluability criteria. The endpoint therefore represents a defined subset and cannot be assumed to describe every age group or every enrolled participant.
The GMT and its confidence interval are appropriate kinds of summaries for antibody titers when analysis is conducted on the log scale, but readers need the actual estimate and interval to judge the magnitude and precision of the result. The registry describes the method without reporting those numerical results. This distinction between a prespecified or registered measure and a reported estimate is central to evidence appraisal: an endpoint definition explains what was intended to be measured, not what was observed.
The design is also statistically consequential. A single-group, open-label study can provide descriptive information, but it does not create the randomized concurrent comparison needed to estimate a controlled between-group effect. The registry explicitly cautions against treating the arms as like-for-like controls. That warning matters particularly for safety summaries, where event counts in separate clinical categories should not be read as evidence of relative risk.
Finally, the record’s many outcome measures, absent analysis records, and unreported multiplicity and missing-data plans leave important reporting questions unresolved. These are not proof of flawed conduct; they identify limits on what can be evaluated from the registry record. Clear results, denominators, analysis populations, and analysis-plan details are necessary for readers to assess uncertainty and interpretability.
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.
Several limitations follow from the specific registry information. First, the numerical result for the primary GMT endpoint and its confidence interval are not reported in the registry record. Although the calculation method and target population are described, the estimate’s magnitude and precision cannot be assessed.
Second, the primary endpoint applies only to participants aged ≥2 to <5 years meeting the stated infection-history and Dose 3 Evaluable Immunogenicity criteria. The number contributing to this analysis and the number not meeting those criteria are not reported in the registry record. The primary endpoint therefore cannot be assumed to represent the full enrolled population described in the study summary.
Third, the study is open label and single group, and the registry says the arms are not a like-for-like control comparison. No randomized controlled treatment contrast can be inferred from this design. The listed safety events are descriptive, and the registry information does not supply the event-term denominators needed to interpret the listed percentages in isolation.
Fourth, the analysis plan, multiplicity approach, missing-data handling, interim analyses, and sample-size justification are not reported in the registry record. The record’s sample-size assumptions describe a planning illustration rather than the original trial design. These omissions limit assessment of how outcome selection, incomplete measurements, or uncertainty were addressed. They do not establish that a particular method was or was not used; they mark what cannot be evaluated from the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study to Evaluate Safety, Tolerability & Immunogenicity of BNT162b2 in Immunocompromised Participants ≥2 Years — NCT04895982.
- Registry record last updated 2024-10-09; status last verified 2024-10.
- Results first posted 2024-10-09.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a completed phase 2b, open-label, single-group study of intramuscular BNT162b2 in immunocompromised participants aged 2 years and older. It reports an enrollment of 124 participants, described as 7 adults and 117 children, and a 4 dose study. The primary endpoint is a neutralizing-antibody GMT 1 month after vaccination 3 among eligible participants aged ≥2 to <5 years without evidence or history of past COVID-19.
The record explains the GMT and confidence-interval method and defines the Dose 3 Evaluable Immunogenicity population. It lists 56 outcome measures and zero analysis records, but the numerical primary GMT result and confidence interval are not reported in the registry record. Safety information is presented descriptively by listed groups; the registry cautions that the arms are not a like-for-like control comparison. The statistical analysis plan, multiplicity approach, and missing-data handling are not reported in the registry record.