Trial Outcomes & Findings for Safety and Immunogenicity Study of Tdap Vaccinations for Plasma Donors (NCT NCT05662852)
NCT ID: NCT05662852
Last Updated: 2026-07-02
Results Overview
An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs are defined as an adverse event occurring after first study treatment. A serious TEAE was defined as an AE that resulted in any of the following outcomes: death; life-threatening; inpatient hospitalization or prolongation of hospitalization; persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions, an important medical event that based on appropriate medical judgment may jeopardize the subject and may require medical or surgical intervention to prevent one of the aforementioned outcomes.
Recruitment status
COMPLETED
Study phase
PHASE2
Target enrollment
107 participants
Primary outcome timeframe
Up to 18 months
Results posted on
2026-07-02
Participant Flow
Subjects were recruited from the Glassboro, New Jersey area during May through November, 2024, without regard to ethnicity, race, or socioeconomic level. Standard recruiting practices such as IRB-approved flyers were used to recruit study volunteers
All participants were "Qualified Donors" who had been qualified for continued plasma donations in accordance with Donor Eligibility requirements found in 21 CFR 630.10 and 630.15, and Source Plasma regulations under 21 CRF 640, Subpart G. A total of 107 participants were consented and screened for eligibility. Seven of these participants did not meet eligibility criteria.
Participant milestones
| Measure |
Tdap for Plasma Donors
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Overall Study
STARTED
|
107
|
|
Overall Study
Treatment Population
|
100
|
|
Overall Study
COMPLETED
|
66
|
|
Overall Study
NOT COMPLETED
|
41
|
Reasons for withdrawal
| Measure |
Tdap for Plasma Donors
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Overall Study
Withdrawal by Subject
|
20
|
|
Overall Study
Adverse Event
|
4
|
|
Overall Study
No Longer Eligible
|
4
|
|
Overall Study
Lost to Follow-up
|
6
|
|
Overall Study
Screen Failure
|
7
|
Baseline Characteristics
One participant was excluded from the analysis as the baseline sample was not processed due to a sample shipment logistically error at the clinical site.
Baseline characteristics by cohort
| Measure |
Tdap for Plasma Donors
n=100 Participants
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=100 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
100 Participants
n=100 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=100 Participants
|
|
Sex: Female, Male
Female
|
21 Participants
n=100 Participants
|
|
Sex: Female, Male
Male
|
79 Participants
n=100 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
1 Participants
n=100 Participants
|
|
Race (NIH/OMB)
Asian
|
2 Participants
n=100 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=100 Participants
|
|
Race (NIH/OMB)
Black or African American
|
28 Participants
n=100 Participants
|
|
Race (NIH/OMB)
White
|
66 Participants
n=100 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=100 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
3 Participants
n=100 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
12 Participants
n=100 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
86 Participants
n=100 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
2 Participants
n=100 Participants
|
|
Region of Enrollment
United States
|
100 Participants
n=100 Participants
|
|
Baseline Anti-tetanus Antibody Titers
|
0.3 IU/mL
n=99 Participants • One participant was excluded from the analysis as the baseline sample was not processed due to a sample shipment logistically error at the clinical site.
|
PRIMARY outcome
Timeframe: Up to 18 monthsAn adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs are defined as an adverse event occurring after first study treatment. A serious TEAE was defined as an AE that resulted in any of the following outcomes: death; life-threatening; inpatient hospitalization or prolongation of hospitalization; persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions, an important medical event that based on appropriate medical judgment may jeopardize the subject and may require medical or surgical intervention to prevent one of the aforementioned outcomes.
Outcome measures
| Measure |
Tdap for Plasma Donors
n=100 Participants
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
|
36 Participants
|
SECONDARY outcome
Timeframe: Baseline, Month 1, Month 2, Month 3, Month 4, Month 5, Month 6, Month 7, Month 8, Month 9, Month 10, Month 11, Month 12, Month 13, Month 18Population: The analysis population includes all participants with an evaluable sample at each specific timepoint. The number of participants analyzed at each visit reflects the total enrolled population (N=100) minus participants who discontinued the study early (dropouts), those with missed study visits, and participants with non-evaluable samples. Summary statistics reflect observed data only; no missing data were imputed.
Anti-tetanus antibody titer levels after each vaccination presented at geometric means (GeoMean) over time.
Outcome measures
| Measure |
Tdap for Plasma Donors
n=100 Participants
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 1
|
10.7 IU/mL
Standard Deviation 1.29
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 2
|
7.4 IU/mL
Standard Deviation 1.07
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 3
|
5.5 IU/mL
Standard Deviation 1.14
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 4
|
5.9 IU/mL
Standard Deviation 1.02
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 5
|
5.2 IU/mL
Standard Deviation 0.89
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 6
|
3.9 IU/mL
Standard Deviation 1.09
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 7
|
4.8 IU/mL
Standard Deviation 1.07
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 8
|
3.7 IU/mL
Standard Deviation 1.24
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 9
|
3.1 IU/mL
Standard Deviation 1.23
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 10
|
4.7 IU/mL
Standard Deviation 0.96
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 11
|
3.2 IU/mL
Standard Deviation 1.22
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 12
|
2.9 IU/mL
Standard Deviation 1.01
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 13
|
3.4 IU/mL
Standard Deviation 1.05
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Screening
|
0.3 IU/mL
Standard Deviation 0.81
|
|
Anti-tetanus Antibody Titers in Participants Over Time
Month 18
|
2.3 IU/mL
Standard Deviation 1.11
|
SECONDARY outcome
Timeframe: Baseline, Month 1, Month 2, Month 3, Month 4, Month 5, Month 6, Month 7, Month 8, Month 9, Month 10, Month 11, Month 12, Month 13, Month 18Population: Multiple participants dropped out of the study early. Missing data were documented in the protocol deviations and summary statistics to reflect the number of observations for which data were provided. No missing data were derived.
The numbers and percentages of participants whose post vaccination antibody levels were \<5 IU/mL; ≥5 IU/mL to 10 IU/mL; \>10 IU/mL to 15 IU/mL; and, \>15 IU/mL after each vaccination.
Outcome measures
| Measure |
Tdap for Plasma Donors
n=100 Participants
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Screening · ≥ 5 to 10 IU/ mL
|
5 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Screening · ≥ 10 to 15 IU/ mL
|
0 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Screening · ≥ 15 IU/ mL
|
0 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 1 · < 5 IU/ mL
|
16 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 1 · ≥ 5 to 10 IU/ mL
|
20 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 1 · ≥ 10 to 15 IU/ mL
|
16 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 1 · ≥ 15 IU/ mL
|
36 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 2 · ≥ 5 to 10 IU/ mL
|
29 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 2 · ≥ 10 to 15 IU/ mL
|
12 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 2 · ≥ 15 IU/ mL
|
18 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 3 · < 5 IU/ mL
|
27 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 3 · ≥ 5 to 10 IU/ mL
|
34 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 3 · ≥ 10 to 15 IU/ mL
|
9 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 4 · < 5 IU/ mL
|
25 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 4 · ≥ 5 to 10 IU/ mL
|
31 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 4 · ≥ 10 to 15 IU/ mL
|
9 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 4 · ≥ 15 IU/ mL
|
8 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 5 · < 5 IU/ mL
|
27 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 5 · ≥ 5 to 10 IU/ mL
|
33 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 5 · ≥ 10 to 15 IU/ mL
|
5 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 5 · ≥ 15 IU/ mL
|
6 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 6 · < 5 IU/ mL
|
32 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 6 · ≥ 5 to 10 IU/ mL
|
22 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 6 · ≥ 10 to 15 IU/ mL
|
4 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 6 · ≥ 15 IU/ mL
|
3 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 7 · < 5 IU/ mL
|
29 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 7 · ≥ 5 to 10 IU/ mL
|
25 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 7 · ≥ 15 IU/ mL
|
5 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 8 · < 5 IU/ mL
|
35 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 8 · ≥ 5 to 10 IU/ mL
|
19 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 8 · ≥ 10 to 15 IU/ mL
|
5 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 9 · < 5 IU/ mL
|
33 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 9 · ≥ 5 to 10 IU/ mL
|
15 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 9 · ≥ 10 to 15 IU/ mL
|
5 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 10 · < 5 IU/ mL
|
28 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 10 · ≥ 5 to 10 IU/ mL
|
26 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 10 · ≥ 10 to 15 IU/ mL
|
6 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 10 · ≥ 15 IU/ mL
|
2 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 11 · < 5 IU/ mL
|
38 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 11 · ≥ 5 to 10 IU/ mL
|
21 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 11 · ≥ 15 IU/ mL
|
0 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 12 · < 5 IU/ mL
|
38 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 12 · ≥ 5 to 10 IU/ mL
|
14 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 12 · ≥ 10 to 15 IU/ mL
|
4 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 12 · ≥ 15 IU/ mL
|
0 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 13 · < 5 IU/ mL
|
42 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 13 · ≥ 5 to 10 IU/ mL
|
1 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 13 · ≥ 15 IU/ mL
|
4 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 18 · < 5 IU/ mL
|
48 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 18 · ≥ 5 to 10 IU/ mL
|
15 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Screening · < 5 IU/ mL
|
94 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 2 · < 5 IU/ mL
|
23 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 3 · ≥ 15 IU/ mL
|
8 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 7 · ≥ 10 to 15 IU/ mL
|
8 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 8 · ≥ 15 IU/ mL
|
3 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 9 · ≥ 15 IU/ mL
|
1 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 11 · ≥ 10 to 15 IU/ mL
|
5 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 13 · ≥ 10 to 15 IU/ mL
|
20 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 18 · ≥ 10 to 15 IU/ mL
|
0 Participants
|
|
Number of Participants With Post Vaccination Anti-tetanus Antibody Range Levels
Month 18 · ≥ 15 IU/ mL
|
0 Participants
|
Adverse Events
Tdap for Plasma Donors
Serious events: 1 serious events
Other events: 36 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Tdap for Plasma Donors
n=100 participants at risk
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Cardiac disorders
Myocardial infarction
|
1.0%
1/100 • From enrollment until end of follow-up, up to 18 months
|
Other adverse events
| Measure |
Tdap for Plasma Donors
n=100 participants at risk
Dose: 0.5 mL; Route: Intramuscular (IM) in the deltoid muscle; Frequency: Every 90 days; Duration: 5 doses over 1 year.
|
|---|---|
|
Gastrointestinal disorders
Discomfort
|
5.0%
5/100 • From enrollment until end of follow-up, up to 18 months
|
|
General disorders
Injection site pain
|
20.0%
20/100 • From enrollment until end of follow-up, up to 18 months
|
|
General disorders
Injection site swelling
|
9.0%
9/100 • From enrollment until end of follow-up, up to 18 months
|
|
Investigations
Blood creatinine increased
|
7.0%
7/100 • From enrollment until end of follow-up, up to 18 months
|
|
Investigations
Fatigue
|
7.0%
7/100 • From enrollment until end of follow-up, up to 18 months
|
|
Nervous system disorders
Headache
|
9.0%
9/100 • From enrollment until end of follow-up, up to 18 months
|
Additional Information
Director, Clinical Data Management
Fast-Track Drugs & Biologics, LLC
Phone: 2406727168
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place