Monitoring immune response and longevity in serum and milk after Tdap administration to postpartum women. The clinical trial will involve women (aged 18 - 45 years) who have just delivered full-term infants (greater than or equal to 37 completed weeks of gestation) at Vanderbilt University Medical Center. The enrollment period will be fifteen months. The duration is over two years of observation.
This is a single site, prospective study involving only one intervention, receipt of a single 0.5 mL intramuscular (IM) dose of Adacel (Tetanus toxoid, reduced diphtheria toxoid and acellular Pertussis) vaccine, among 55 healthy post partum women. The purpose of the study is to examine the immune responses and subsequent decline in serum and breast milk antibody titers over two years of observation. The clinical trial will involve women (aged 18 - 45 years) who have just delivered full-term infants (greater than or equal to 37 completed weeks of gestation) at Vanderbilt University Medical Center. One particular population at Vanderbilt to target will be the "centering prenatal care group" that has breastfeeding rates as high as 75 percent at hospital discharge and maintained at 20 percent at 6 months. The enrollment period will be fifteen months. The subjects, staff assessing subjects, and laboratory personnel will be aware of receipt of the vaccine. Since only a single vaccine product is being utilized, there is no blinding needed of the subjects or staff.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Enrollment
55
55 postpartum subjects receive a single intramuscular (IM) 0.5 mL dose of Adacel® (Tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine adsorbed).
Vanderbilt University - Pediatric - Vanderbilt Vaccine Research Center
Nashville, Tennessee, United States
Geometric Mean Fold Rise in Serum Immunoglobulin G (IgG) by ELISA at Week 2
Blood was collected from participants at baseline prior to vaccination and at 2 weeks after vaccination for assessment of IgG by ELISA against the pertussis toxin (PT), filamentous hemaggluttinin (FHA), pertactin (PRN) and fimbrae (FIM) antigens. Antibody concentrations were reported as ELISA units per milliliter (EU/mL). The geometric mean of participants' fold rise in antibody concentrations from baseline to post vaccination was calculated, along with the 95% confidence interval (CI).
Time frame: Prior to and 2 weeks following vaccination
Geometric Mean Fold Rise in Serum IgG by ELISA at Week 6
Blood was collected from participants at baseline prior to vaccination and at 6 weeks after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. The geometric mean of participants' fold rise in antibody concentrations from baseline to post vaccination was calculated, along with the 95% CI.
Time frame: Prior to and 6 weeks following vaccination
Geometric Mean Fold Rise in Serum IgG by ELISA at Month 6
Blood was collected from participants at baseline prior to vaccination and at 6 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. The geometric mean of participants' fold rise in antibody concentrations from baseline to post vaccination was calculated, along with the 95% CI.
Time frame: Prior to and 6 months following vaccination
Geometric Mean Fold Rise in Serum IgG by ELISA at Month 12
Blood was collected from participants at baseline prior to vaccination and at 12 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. The geometric mean of participants' fold rise in antibody concentrations from baseline to post vaccination was calculated, along with the 95% CI.
Time frame: Prior to and 12 months following vaccination
Geometric Mean Fold Rise in Serum IgG by ELISA at Month 18
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Blood was collected from participants at baseline prior to vaccination and at 18 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. The geometric mean of participants' fold rise in antibody concentrations from baseline to post vaccination was calculated, along with the 95% CI.
Time frame: Prior to and 18 months following vaccination
Geometric Mean Fold Rise in Serum IgG by ELISA at Month 24
Blood was collected from participants at baseline prior to vaccination and at 24 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. The geometric mean of participants' fold rise in antibody concentrations from baseline to post vaccination was calculated, along with the 95% CI.
Time frame: Prior to and 24 months following vaccination
ELISA Geometric Mean Concentrations (GMC) of Serum IgG to PT, FHA, PRN and FIM at Baseline
Blood was collected from participants at baseline prior to vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. Antibody concentrations were reported as ELISA units per milliliter (EU/mL). A value of 5 EU/mL was imputed for results reported as below the lower limit of quantitation (LLOQ) (\<10 EU/mL). The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: Baseline (prior to vaccination)
ELISA GMCs of Serum IgG to PT, FHA, PRN and FIM at Week 2
Blood was collected from participants at 2 weeks after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. A value of 5 EU/mL was imputed for results reported as below LLOQ. The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: 2 weeks post vaccination
ELISA GMCs of Serum IgG to PT, FHA, PRN and FIM at Week 6
Blood was collected from participants at 6 weeks after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. A value of 5 EU/mL was imputed for results reported as below LLOQ. The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: 6 weeks post vaccination
ELISA GMCs of Serum IgG to PT, FHA, PRN and FIM at Month 6
Blood was collected from participants at 6 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. A value of 5 EU/mL was imputed for results reported as below LLOQ. The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: 6 months post vaccination
ELISA GMCs of Serum IgG to PT, FHA, PRN and FIM at Month 12
Blood was collected from participants at 12 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. A value of 5 EU/mL was imputed for results reported as below LLOQ. The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: 12 months post vaccination
ELISA GMCs of Serum IgG to PT, FHA, PRN and FIM at Month 18
Blood was collected from participants at 18 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. A value of 5 EU/mL was imputed for results reported as below LLOQ. The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: 18 months post vaccination
ELISA GMCs of Serum IgG to PT, FHA, PRN and FIM at Month 24
Blood was collected from participants at 24 months after vaccination for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens. A value of 5 EU/mL was imputed for results reported as below LLOQ. The geometric mean of participants' concentrations at the timepoint was calculated, along with the 95% CI.
Time frame: 24 months post vaccination
Count of Participants With 4-fold Rise in ELISA Antibody Concentrations at Week 2
Blood samples were collected from participants for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens at baseline prior to vaccination and 2 weeks after vaccination. A 4-fold rise in antibody concentration from prior to vaccination was defined as a post-vaccination IgG greater than or equal to 40 EU/mL for participants with baseline IgG concentrations less than the LLOQ (10), or 4 times the baseline IgG concentration for baseline IgG concentrations greater than the LLOQ.
Time frame: Prior to and 2 weeks after vaccination
Count of Participants With 4-fold Rise in ELISA Antibody Concentrations at Week 6
Blood samples were collected from participants for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens at baseline prior to vaccination and 6 weeks after vaccination. A 4-fold rise in antibody concentration from prior to vaccination was defined as a post-vaccination IgG greater than or equal to 40 EU/mL for participants with baseline IgG concentrations less than the LLOQ (10), or 4 times the baseline IgG concentration for baseline IgG concentrations greater than the LLOQ.
Time frame: Prior to and 6 weeks after vaccination
Count of Participants With 4-fold Rise in ELISA Antibody Concentrations at Month 6
Blood samples were collected from participants for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens at baseline prior to vaccination and 6 months after vaccination. A 4-fold rise in antibody concentration from prior to vaccination was defined as a post-vaccination IgG greater than or equal to 40 EU/mL for participants with baseline IgG concentrations less than the LLOQ (10), or 4 times the baseline IgG concentration for baseline IgG concentrations greater than the LLOQ.
Time frame: Prior to and 6 months after vaccination
Count of Participants With 4-fold Rise in ELISA Antibody Concentrations at Month 12
Blood samples were collected from participants for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens at baseline prior to vaccination and 12 months after vaccination. A 4-fold rise in antibody concentration from prior to vaccination was defined as a post-vaccination IgG greater than or equal to 40 EU/mL for participants with baseline IgG concentrations less than the LLOQ (10), or 4 times the baseline IgG concentration for baseline IgG concentrations greater than the LLOQ.
Time frame: Prior to and 12 months after vaccination
Count of Participants With 4-fold Rise in ELISA Antibody Concentrations at Month 18
Blood samples were collected from participants for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens at baseline prior to vaccination and 18 months after vaccination. A 4-fold rise in antibody concentration from prior to vaccination was defined as a post-vaccination IgG greater than or equal to 40 EU/mL for participants with baseline IgG concentrations less than the LLOQ (10), or 4 times the baseline IgG concentration for baseline IgG concentrations greater than the LLOQ.
Time frame: Prior to and 18 months after vaccination
Count of Participants With 4-fold Rise in ELISA Antibody Concentrations at Month 24
Blood samples were collected from participants for assessment of IgG by ELISA against the PT, FHA, PRN and FIM antigens at baseline prior to vaccination and 24 months after vaccination. A 4-fold rise in antibody concentration from prior to vaccination was defined as a post-vaccination IgG greater than or equal to 40 EU/mL for participants with baseline IgG concentrations less than the LLOQ (10), or 4 times the baseline IgG concentration for baseline IgG concentrations greater than the LLOQ.
Time frame: Prior to and 24 months after vaccination
Kinetics of the ELISA IgG Antibody Rise in Serum
The assessment of the kinetics of the ELISA IgG antibody rise in serum was defined by the protocol as the geometric mean fold rise at each timepoint (reported separately above). No additional analysis was pre-defined or performed for this outcome measure.
Time frame: Prior to and following Tdap, through 24 months post-vaccination
ELISA GMC of Breast Milk IgA to Pertussis Toxin (PT) at Baseline.
Breast milk (colostrum) was collected from participants at baseline prior to vaccination for assessment of secretory IgA (sIgA) to the PT antigen by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL along with the 95% confidence interval. The lower limit of quantitation (LLOQ) of the assay was 10. Results of \<10 were reported as half the LLOQ (5).
Time frame: Baseline (prior to vaccination)
ELISA GMC of Breast Milk IgA to PT at Week 2
Breast milk was collected from participants at 2 weeks after vaccination for assessment of secretory IgA (sIgA) to PT and FHA by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL. Note that for the PT at this timepoint, all participants had a value of 5, the imputed value for below the LLOQ of the assay (\<10), and so the 95% CI is not reported, as there was no measurable variability in the data. The range is reported.
Time frame: 2 weeks post vaccination
ELISA GMC of Breast Milk IgA to PT at Week 6
Breast milk was collected from participants at 6 weeks after vaccination for assessment of secretory IgA (sIgA) to PT and FHA by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL. Note that for the PT at this timepoint, all participants had a value of 5, the imputed value for below the LLOQ of the assay (\<10), and so the 95% CI is not reported, as there was no measurable variability in the data. The range is reported.
Time frame: 6 weeks post vaccination
ELISA GMC of Breast Milk IgA to PT at Month 6
Breast milk was collected from participants at 6 weeks after vaccination for assessment of secretory IgA (sIgA) to PT and FHA by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL. Note that for the PT at this timepoint, all participants had a value of 5, the imputed value for below the LLOQ of the assay (\<10), and so the 95% CI is not reported, as there was no measurable variability in the data. The range is reported.
Time frame: 6 months post vaccination
ELISA GMC of Breast Milk IgA to FHA at Baseline.
Breast milk (colostrum) was collected from participants at baseline prior to vaccination for assessment of secretory IgA (sIgA) to the FHA antigen by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL along with the 95% confidence interval.
Time frame: Baseline (prior to vaccination)
ELISA GMC of Breast Milk IgA to FHA at Week 2.
Breast milk was collected from participants at 2 weeks post vaccination for assessment of secretory IgA (sIgA) to the FHA antigen by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL along with the 95% confidence interval.
Time frame: 2 weeks post vaccination
ELISA GMC of Breast Milk IgA to FHA at Week 6.
Breast milk was collected from participants at 6 weeks post vaccination for assessment of secretory IgA (sIgA) to the FHA antigen by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL. Note that for the FHA at this timepoint, all participants had a concentration of 5, the imputed value for below the LLOQ of the assay (\<10), and so the 95% CI is not reported, as there was no measurable variability in the data. The range is reported.
Time frame: 6 weeks post vaccination
ELISA GMC of Breast Milk IgA to FHA at Month 6.
Breast milk was collected from participants at 6 months post vaccination for assessment of secretory IgA (sIgA) to the FHA antigen by ELISA. Available data at the timepoint were summarized by geometric mean of the concentration as reported in EU/mL along with the 95% confidence interval.
Time frame: 6 months post vaccination
ELISA GMC of Breast Milk IgA to PRN and FIM by Study Day.
Breast milk (colostrum) was collected from participants at baseline prior to vaccination for assessment of secretory IgA (sIgA) to the PRN and FIM antigen by ELISA. Available data at the timepoint were to be summarized by geometric mean of the concentration as reported in EU/mL along with the 95% confidence interval. The lower limit of quantitation (LLOQ) of the assay was 10 EU/mL.
Time frame: Baseline (prior to vaccination), Week 2, Week 6 and Month 6 post vaccination
Proportion of Participants With 4-fold Rise in Antibody in Breast Milk by Study Day.
Breast milk samples were collected from participants for evaluation of PT and FHA secretory IgA (sIgA) by ELISA. The lower limit of quantification (LLOQ) for the assay was 10 EU/mL. A 4-fold rise in concentration from prior to vaccination was defined as a post-vaccination sIgA concentration greater than or equal to 40 EU/mL for participants with baseline sIgA concentrations less than the LLOQ, or 4 times the baseline sIgA concentration for baseline sIgA concentrations greater than the LLOQ.
Time frame: Prior to vaccination, 2 weeks, 6 weeks, and 6 months after vaccination
Geometric Mean Fold Rise in Antibody Concentrations Assessed by ELISA in Breast Milk by Study Day
Breast milk samples were collected from participants for evaluation of secretory IgA (sIgA) by ELISA. Geometric mean fold rise was defined as the geometric mean of participants' fold rise in post vaccination sIgA relative to the pre-vaccination sIgA.
Time frame: Prior to vaccination, 2 weeks, 6 weeks, and 6 months after vaccination
Kinetics of the ELISA IgG Antibody Decline in Breast Milk Expressed in EU/ml.
Breast milk samples were collected from participants for evaluation of PT and FHA secretory IgA (sIgA) by ELISA. The protocol defined kinetics as assessment at each post-vaccination timepoint of the geometric mean fold rise, defined as the geometric mean of participants' fold rise in post vaccination sIgA relative to the pre-vaccination sIgA.
Time frame: Prior to vaccination, 2 weeks, 6 weeks, and 6 months after vaccination