Trial · NCT03579459
Evaluation Of Clostridium Difficile Vaccine Lot Consistency In Healthy Adults 65 To 85 Years Of Age
NCT03579459, Phase 3, Completed, Pfizer; results first posted 2023-01-19
3 sourcestrials-2026-11-12-0.5.0
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ConductScience Library. Evaluation Of Clostridium Difficile Vaccine Lot Consistency In Healthy Adults 65 To 85 Years Of Age. Trials, record NCT03579459. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03579459
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- Evaluation Of Clostridium Difficile Vaccine Lot Consistency In Healthy Adults 65 To 85 Years Of Age
- NCT number
- NCT03579459
- Status
- Completed
- Phases
- Phase 3
- Enrollment
- 1,317 participants, actual
- Lead sponsor
- Pfizer
- Conditions
- Clostridium Difficile Associated Disease
- Interventions
- Clostridium difficile vaccine, placebo
- First posted
- 2018-07-06
- Last updated
- 2023-01-19
- Results first posted
- 2023-01-19
Source ClinicalTrials.gov
Registered outcomes9
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | At Month 7 | GMC was calculated as the mean of the assay results after making the logarithm transformation and then back transformation to its original scale. Confidence intervals (CIs) were back transformations of CIs based on the Student t distribution for the mean logarithm of the concentrations. Clostridium difficile toxin A and toxin B were inactivated by a combination of genetic mutations to decrease toxin activity and chemical treatments were done prior to final purification and formulation of the drug substance. |
| Primary | Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 1 | Within 7 days after Vaccination 1 at Month 0 | Local reactions included pain at injection site, redness and swelling. These were recorded by participants in an electronic diary (e-diary). Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Redness and swelling were measured and recorded in measuring device units. One measuring device unit= 0.5 centimeter (cm) and graded as mild: 2.5 to 5.0 cm, moderate: greater than (\>) 5.0 to 10.0 cm, severe: \>10.0 cm, Grade 4 indicated necrosis or exfoliative dermatitis for redness and necrosis for swelling. The maximum severity was defined as highest grading of each local reaction within 7 days of vaccination. Events were classified as Grade 4 based on study investigator's judgement. |
| Primary | Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 2 | Within 7 days after Vaccination 2 at Month 1 | Local reactions included pain at injection site, redness and swelling. These were recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Redness and swelling were measured and recorded in measuring device units. One measuring device unit= 0.5 cm and graded as mild: 2.5 to 5.0 cm, moderate: \> 5.0 to 10.0 cm, severe: \>10.0 cm, Grade 4 indicated necrosis or exfoliative dermatitis for redness and necrosis for swelling. The maximum severity was defined as highest grading of each local reaction within 7 days of vaccination. Events were classified as Grade 4 based on study investigator's judgement. |
| Primary | Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 3 | Within 7 days after Vaccination 3 at Month 6 | Local reactions included pain at injection site, redness and swelling. These were recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Redness and swelling were measured and recorded in measuring device units. One measuring device unit= 0.5 cm and graded as mild: 2.5 to 5.0 cm, moderate: \> 5.0 to 10.0 cm, severe: \>10.0 cm, Grade 4 indicated necrosis or exfoliative dermatitis for redness and necrosis for swelling. The maximum severity was defined as highest grading of each local reaction within 7 days of vaccination. Events were classified as Grade 4 based on study investigator's judgement. |
| Primary | Percentage of Participants Reporting Systemic Events by Maximum Severity Within 7 Days After Vaccination 1 | Within 7 days after Vaccination 1 at Month 0 | Systemic events included fever, fatigue, headache, joint pain, muscle pain and vomiting. These were recorded by participants in an e-diary. Fever was categorized as: mild: (38.0 to 38.4 degree Celsius \[deg C\]), moderate: (38.5 to 38.9 deg C), severe (39.0 to 40.0 deg C), grade 4: \>40 deg C. Fatigue, headache, joint pain and muscle pain were graded as mild: did not interfere with activity, moderate: some interference with activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Vomiting was graded as mild: 1 to 2 times in 24 hours, moderate: \>2 times in 24 hours, severe: required intravenous hydration, grade 4: emergency room visit or hospitalization for hypotensive shock. The maximum severity was defined as highest grading of each systemic event within 7 days of vaccination. Events were classified as Grade 4 based on study investigator's judgement. |
| Primary | Percentage of Participants Reporting Systemic Events by Maximum Severity Within 7 Days After Vaccination 2 | Within 7 days after Vaccination 2 at Month 1 | Systemic events included fever, fatigue, headache, joint pain, muscle pain and vomiting. These were recorded by participants in an e-diary. Fever was categorized as: mild: (38.0 to 38.4 deg C), moderate: (38.5 to 38.9 deg C), severe (39.0 to 40.0 deg C), grade 4: \>40 deg C. Fatigue, headache, joint pain and muscle pain were graded as mild: did not interfere with activity, moderate: some interference with activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Vomiting was graded as mild: 1 to 2 times in 24 hours, moderate: \>2 times in 24 hours, severe: required intravenous hydration, grade 4: emergency room visit or hospitalization for hypotensive shock. The maximum severity was defined as highest grading of each systemic event within 7 days of vaccination. Events were classified as Grade 4 based on study investigator's judgement. |
| Primary | Percentage of Participants Reporting Systemic Events by Maximum Severity Within 7 Days After Vaccination 3 | Within 7 days after Vaccination 3 at Month 6 | Systemic events included fever, fatigue, headache, joint pain, muscle pain and vomiting. These were recorded by participants in an e-diary. Fever was categorized as: mild: (38.0 to 38.4 deg C), moderate: (38.5 to 38.9 deg C), severe (39.0 to 40.0 deg C), grade 4: \>40 deg C. Fatigue, headache, joint pain and muscle pain were graded as mild: did not interfere with activity, moderate: some interference with activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Vomiting was graded as mild: 1 to 2 times in 24 hours, moderate: \>2 times in 24 hours, severe: required intravenous hydration, grade 4: emergency room visit or hospitalization for hypotensive shock. The maximum severity was defined as highest grading of each systemic event within 7 days of vaccination. Events were classified as Grade 4 based on study investigator's judgement. |
| Primary | Percentage of Participants With Adverse Events (AEs) Through 1 Month After Last Study Vaccination | From Day 1 to 1 month after last vaccination (Up to Month 7) | An AE was defined as any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. AEs included both serious and all non-serious adverse events (NSAEs). Only AEs and NSAEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure. |
| Primary | Percentage of Participants Reporting Serious Adverse Events (SAEs) | From Day 1 to 1 month after last vaccination (Up to Month 7) | An SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening (immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity (substantial disruption of the ability to conduct normal life functions); congenital anomaly/birth defect; or that was considered as an important medical event. |
Source ClinicalTrials.gov
Outcomes9
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | At Month 7 | Evaluable immunogenicity(EI)population=enrolled participants who received all 3 doses of investigational product to which they were randomized; blood drawn for analysis within 23-47 days after visit 4(Month 6)had valid, determinate assay results for either toxinA or B for specified analysis and no major protocol deviations. Placebo arm is not reported as GMC was planned to be evaluated only for 3 vaccine lots. Here,'Number Analyzed' refers to number of participants evaluable for specific toxins. | Neutralization units per mL | GEOMETRIC_MEAN |
| PRIMARY | Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 1 | Within 7 days after Vaccination 1 at Month 0 | Safety analysis population included all participants who received at least 1 dose of the investigational product. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 2 | Within 7 days after Vaccination 2 at Month 1 | Safety analysis population included all participants who received at least 1 dose of the investigational product. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 3 | Within 7 days after Vaccination 3 at Month 6 | Safety analysis population included all participants who received at least 1 dose of the investigational product. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants Reporting Systemic Events by Maximum Severity Within 7 Days After Vaccination 1 | Within 7 days after Vaccination 1 at Month 0 | Safety analysis population included all participants who received at least 1 dose of the investigational product. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants Reporting Systemic Events by Maximum Severity Within 7 Days After Vaccination 2 | Within 7 days after Vaccination 2 at Month 1 | Safety analysis population included all participants who received at least 1 dose of the investigational product. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants Reporting Systemic Events by Maximum Severity Within 7 Days After Vaccination 3 | Within 7 days after Vaccination 3 at Month 6 | Safety analysis population included all participants who received at least 1 dose of the investigational product. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants With Adverse Events (AEs) Through 1 Month After Last Study Vaccination | From Day 1 to 1 month after last vaccination (Up to Month 7) | Safety analysis population included all participants who received at least 1 dose of the investigational product. Pooled data for Clostridium difficile vaccine (lot 1+lot 2+lot 3) is reported for this outcome measure as pre-specified in the statistical analysis plan. | Percentage of participants | NUMBER |
| PRIMARY | Percentage of Participants Reporting Serious Adverse Events (SAEs) | From Day 1 to 1 month after last vaccination (Up to Month 7) | Safety analysis population included all participants who received at least 1 dose of the investigational product. Pooled data for Clostridium difficile vaccine (lot 1+lot 2+lot 3) is reported for this outcome measure as pre-specified in the statistical analysis plan. | Percentage of participants | NUMBER |
Source ClinicalTrials.gov
Results by group444
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | Clostridium Difficile Vaccine: Lot 1 | Toxin A | 878.8 | 95% Confidence Interval 786.3 to 982.2 | Neutralization units per mL |
| Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | Clostridium Difficile Vaccine: Lot 2 | Toxin A | 873.0 | 95% Confidence Interval 779.2 to 978.1 | Neutralization units per mL |
| Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | Clostridium Difficile Vaccine: Lot 3 | Toxin A | 872.9 | 95% Confidence Interval 782.6 to 973.5 | Neutralization units per mL |
| Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | Clostridium Difficile Vaccine: Lot 1 | Toxin B | 5823.9 | 95% Confidence Interval 5041.0 to 6728.4 | Neutralization units per mL |
| Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | Clostridium Difficile Vaccine: Lot 2 | Toxin B | 5462.8 | 95% Confidence Interval 4733.4 to 6304.7 | Neutralization units per mL |
| Geometric Mean Concentrations (GMCs) of Clostridium Difficile Toxin A and Toxin B Specific Neutralizing Antibodies at Month 7 | Clostridium Difficile Vaccine: Lot 3 | Toxin B | 5426.0 | 95% Confidence Interval 4724.4 to 6231.8 | Neutralization units per mL |
| Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 1 | Clostridium Difficile Vaccine: Lot 1 | Pain at injection site: Mild | 14.2 | 95% Confidence Interval 10.6 to 18.4 | Percentage of participants |
| Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 1 | Clostridium Difficile Vaccine: Lot 2 | Pain at injection site: Mild | 15.9 | 95% Confidence Interval 12.1 to 20.4 | Percentage of participants |
| Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 1 | Clostridium Difficile Vaccine: Lot 3 | Pain at injection site: Mild | 17.4 | 95% Confidence Interval 13.4 to 22.0 | Percentage of participants |
| Percentage of Participants Reporting Local Reactions by Maximum Severity Within 7 Days After Vaccination 1 | Placebo | Pain at injection site: Mild | 4.9 | 95% Confidence Interval 2.8 to 7.9 | Percentage of participants |
1 to 10 of 444Source ClinicalTrials.gov
See all 444 results by groupParticipant flow24
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Clostridium Difficile Vaccine: Lot 1 | 330 | |
| Overall Study | STARTED | Clostridium Difficile Vaccine: Lot 2 | 327 | |
| Overall Study | STARTED | Clostridium Difficile Vaccine: Lot 3 | 328 | |
| Overall Study | STARTED | Placebo | 332 | |
| Overall Study | Dose 1 | Clostridium Difficile Vaccine: Lot 1 | 330 | |
| Overall Study | Dose 1 | Clostridium Difficile Vaccine: Lot 2 | 325 | |
| Overall Study | Dose 1 | Clostridium Difficile Vaccine: Lot 3 | 328 | |
| Overall Study | Dose 1 | Placebo | 331 | |
| Overall Study | Dose 2 | Clostridium Difficile Vaccine: Lot 1 | 324 | |
| Overall Study | Dose 2 | Clostridium Difficile Vaccine: Lot 2 | 318 |
1 to 10 of 24Source ClinicalTrials.gov
See all 24 participant flowAdverse events158
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Diarrhoea | Gastrointestinal disorders | Clostridium Difficile Vaccine (Pooled Lots) | 11 | 983 | |
| other | Diarrhoea | Gastrointestinal disorders | Placebo | 3 | 331 | |
| other | Vomiting (VOMITING) | Gastrointestinal disorders | Clostridium Difficile Vaccine (Pooled Lots) | 25 | 983 | |
| other | Vomiting (VOMITING) | Gastrointestinal disorders | Placebo | 6 | 331 | |
| other | Fatigue (FATIGUE) | General disorders | Clostridium Difficile Vaccine (Pooled Lots) | 369 | 983 | |
| other | Fatigue (FATIGUE) | General disorders | Placebo | 96 | 331 | |
| other | Fatigue | General disorders | Clostridium Difficile Vaccine (Pooled Lots) | 5 | 983 | |
| other | Fatigue | General disorders | Placebo | 4 | 331 | |
| other | Injection site erythema (REDNESS) | General disorders | Clostridium Difficile Vaccine (Pooled Lots) | 93 | 983 | |
| other | Injection site erythema (REDNESS) | General disorders | Placebo | 7 | 331 |
1 to 10 of 158Source ClinicalTrials.gov
See all 158 adverse eventsAdverse event totals6
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Clostridium Difficile Vaccine (Pooled Lots) | 2 | 983 |
| Total, all-cause mortality | Placebo | 2 | 331 |
| Total, other adverse events | Clostridium Difficile Vaccine (Pooled Lots) | 694 | 983 |
| Total, other adverse events | Placebo | 175 | 331 |
| Total, serious adverse events | Clostridium Difficile Vaccine (Pooled Lots) | 41 | 983 |
| Total, serious adverse events | Placebo | 15 | 331 |
Source ClinicalTrials.gov
Papers1
The papers the trial lists on ClinicalTrials.gov.
| PMID | Listed as |
|---|---|
| 37977942 | DERIVED |
Source PubMed
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons2
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison | Source |
|---|---|
| Clostridium Difficile Vaccine (Pooled Lots) vs Placebo: deaths from any cause | Trial comparisons |
| Clostridium Difficile Vaccine (Pooled Lots) vs Placebo: serious adverse events | Trial comparisons |
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
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Read this trial from software.
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