Pertussis, Pregnancy Related
Conditions
Brief summary
This study evaluated the seroprevalence of Bordetella pertussis antibodies and anti-pertussis antibody response after a single dose of reduced-antigen, combined diphtheria, tetanus, and acellular pertussis vaccine (Tdap) in pregnant Thai women. All seronegative participants received Tdap, while seropositive participants were equally randomized into 2 groups. Half of seropositive participants received Tdap and the other half received tetanus-diphtheria (Td) as standard protocol.
Detailed description
The primary objective of this study was to determine the seroprevalence of anti-pertussis toxin antibodies (anti-PT IgG) among pregnant Thai women. The secondary objectives were to evaluate antibody response after Tdap vaccination between seronegative and seropositive participants and to compare the different antibody titers at delivery among seropositive participants who received Tdap to those who received tetanus-diphtheria vaccine (Td). The sample size calculation was based on the primary objective. Randomized clinical trial was performed for the latter secondary objective.
Interventions
BIOLOGICALTdap vaccine
A single dose of Tdap vaccine at GA 27 - 36 weeks
Sponsors
Mahidol University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Thai pregnant women age at least 18 years * No known underlying disease * Singleton pregnancy without maternal or fetal complications * Gestational age not more than 20 weeks at the time of recruitment * Desired for delivery at Siriraj Hospital
Exclusion criteria
* Pregnant women who have any contraindication to Tdap vaccine including 1. History of serious allergic reaction to any components of Tdap vaccine 2. History of seizure or coma after receiving Tdap vaccine in childhood 3. Having an underlying disease involving central nervous system (e.g., epilepsy, Guillain-Barré syndrome) * History of serious reactions after receiving Tdap vaccine (e.g., severe pain, severe swelling at the injection site) * Recently had Tdap vaccine injection * Denied for Tdap vaccine injection
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The Seroprevalence of Anti-pertussis Toxin Antibodies (Anti-PT IgG) in Pregnant Thai Women | Four months | Percentage of participants who were seropositive for anti-pertussis toxin antibodies (anti-PT IgG). The overall number of 129 participants is greater than the number of 42 participants include in the Particiant Flow Module because it was the sample size calculated based on the primary objective, which was the seroprevalence of anti-pertussis antibodies in pregnant Thai women. Randomized clinical trial on 42 seropositive participants was performed for one of the secondary objectives, which was to compare the different anti-PT IgG at delivery among seropositive participants who received Tdap to those who received Td. |
Secondary
| Measure | Time frame |
|---|---|
| Change From Baseline in Anti-pertussis Toxin Immunoglobulin G Levels Among Seropositive Participants Who Received Tdap to Those Who Received Td | Eight months |
Countries
Thailand
Participant flow
Pre-assignment details
The sample size of 129 participants was calculated based on the primary objective. Randomized clinical trial on 42 seropositive participants was performed for one of the secondary objectives, which was to compare the different anti-PT IgG at delivery among seropositive participants who received Tdap to those who received Td.
Participants by arm
| Arm | Count |
|---|---|
| Experimental A single dose of Tdap vaccine at GA 27 - 36 weeks
Tdap vaccine: A single dose of Tdap vaccine at GA 27 - 36 weeks | 18 |
| Active Comparator dT vaccine as standard protocol | 13 |
| Total | 31 |
Baseline characteristics
| Characteristic | Active Comparator | Total | Experimental |
|---|---|---|---|
| Age, Continuous | 28.5 years STANDARD_DEVIATION 6 | 29.2 years STANDARD_DEVIATION 6.8 | 29.8 years STANDARD_DEVIATION 7.4 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Sex/Gender, Customized Female | 13 Participants | 31 Participants | 18 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 18 | 0 / 13 |
| other Total, other adverse events | 12 / 18 | 12 / 13 |
| serious Total, serious adverse events | 0 / 18 | 0 / 13 |
Outcome results
Primary
The Seroprevalence of Anti-pertussis Toxin Antibodies (Anti-PT IgG) in Pregnant Thai Women
Percentage of participants who were seropositive for anti-pertussis toxin antibodies (anti-PT IgG). The overall number of 129 participants is greater than the number of 42 participants include in the Particiant Flow Module because it was the sample size calculated based on the primary objective, which was the seroprevalence of anti-pertussis antibodies in pregnant Thai women. Randomized clinical trial on 42 seropositive participants was performed for one of the secondary objectives, which was to compare the different anti-PT IgG at delivery among seropositive participants who received Tdap to those who received Td.
Time frame: Four months
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| All Participants | The Seroprevalence of Anti-pertussis Toxin Antibodies (Anti-PT IgG) in Pregnant Thai Women | 43 Participants |
Secondary
Change From Baseline in Anti-pertussis Toxin Immunoglobulin G Levels Among Seropositive Participants Who Received Tdap to Those Who Received Td
Time frame: Eight months
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | Change From Baseline in Anti-pertussis Toxin Immunoglobulin G Levels Among Seropositive Participants Who Received Tdap to Those Who Received Td | 42 IU/ml |
| Active Comparator | Change From Baseline in Anti-pertussis Toxin Immunoglobulin G Levels Among Seropositive Participants Who Received Tdap to Those Who Received Td | -7.4 IU/ml |