Trial Outcomes & Findings for Effectiveness of Maternal Immunization With Boostrix at Preventing Pertussis Among Infants <2 Months Old in the United States (NCT NCT03973905)
NCT ID: NCT03973905
Last Updated: 2020-07-07
Results Overview
Vaccine effectiveness at preventing pertussis occurrence in infants \< 2 months old is assessed by comparing the Boostrix immunization status during the third pregnancy trimester in mothers of infant pertussis cases and matched controls. The association between maternal Boostrix vaccination and pertussis in infants was analyzed using conditional logistic regression. The multivariate analysis was performed to obtain the adjusted values. Covariates that were statistically significant in the univariate analysis or considered as clinically significant were included in the multivariable conditional logistic regression model. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
COMPLETED
290 participants
During the data collection period (from 1 January 2011 to 31 December 2014)
2020-07-07
Participant Flow
The present analysis has been performed on the data set of a case-control study conducted in 6 US Emerging Infection Program Network states, either statewide (4 states) or in select counties (2 states) by Skoff et al., 2017.
The primary study was a case-control study evaluating the effectiveness of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines (Boostrix and Adacel) administered during pregnancy in preventing pertussis in infants.
Participant milestones
| Measure |
Pertussis Case Group
Infant subjects of at least 2 days old and less than (\<) 2 months old, who met the pertussis diagnosis definition (laboratory confirmed pertussis, epidemiological linkage to a laboratory-confirmed case, clinically compatible illness), and who met the case infants inclusion criteria (resided in the catchment area on their cough onset date, were born in a hospital in their state of residence, had at least 37 weeks gestational age at birth, were neither adopted, nor in foster care and did not live in a residential care facility) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Control Group
Infant subjects of at least 2 days old and less than (\<) 2 months old, who did not have a pertussis diagnosis prior to the cough onset date and who met the inclusion criteria for control infants (were born on a hospital in their state of residence, were at least 37 weeks gestational age at birth, were neither adopted, nor in foster care, did not live in a residential care facility, were born at the same hospital as the case infant) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
|---|---|---|
|
Overall Study
STARTED
|
107
|
183
|
|
Overall Study
COMPLETED
|
107
|
183
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Effectiveness of Maternal Immunization With Boostrix at Preventing Pertussis Among Infants <2 Months Old in the United States
Baseline characteristics by cohort
| Measure |
Pertussis Case Group
n=107 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who met the pertussis diagnosis definition (laboratory confirmed pertussis, epidemiological linkage to a laboratory-confirmed case, clinically compatible illness), and who met the case infants inclusion criteria (resided in the catchment area on their cough onset date, were born in a hospital in their state of residence, had at least 37 weeks gestational age at birth, were neither adopted, nor in foster care and did not live in a residential care facility) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Control Group
n=183 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who did not have a pertussis diagnosis prior to the cough onset date and who met the inclusion criteria for control infants (were born on a hospital in their state of residence, were at least 37 weeks gestational age at birth, were neither adopted, nor in foster care, did not live in a residential care facility, were born at the same hospital as the case infant) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Total
n=290 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
Infant's age (weeks)
|
5.0 Weeks
STANDARD_DEVIATION 1.9 • n=5 Participants
|
4.8 Weeks
STANDARD_DEVIATION 2.0 • n=7 Participants
|
4.9 Weeks
STANDARD_DEVIATION 2.0 • n=5 Participants
|
|
Sex: Female, Male
Female
|
49 Participants
n=5 Participants
|
90 Participants
n=7 Participants
|
139 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
58 Participants
n=5 Participants
|
93 Participants
n=7 Participants
|
151 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
White
|
88 Participants
n=5 Participants
|
140 Participants
n=7 Participants
|
228 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Black
|
9 Participants
n=5 Participants
|
13 Participants
n=7 Participants
|
22 Participants
n=5 Participants
|
|
Race/Ethnicity, Customized
Other-unspecified
|
10 Participants
n=5 Participants
|
30 Participants
n=7 Participants
|
40 Participants
n=5 Participants
|
PRIMARY outcome
Timeframe: During the data collection period (from 1 January 2011 to 31 December 2014)Population: The analysis includes cases and at least one matched control born from mothers either unvaccinated or vaccinated with Boostrix. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Vaccine effectiveness at preventing pertussis occurrence in infants \< 2 months old is assessed by comparing the Boostrix immunization status during the third pregnancy trimester in mothers of infant pertussis cases and matched controls. The association between maternal Boostrix vaccination and pertussis in infants was analyzed using conditional logistic regression. The multivariate analysis was performed to obtain the adjusted values. Covariates that were statistically significant in the univariate analysis or considered as clinically significant were included in the multivariable conditional logistic regression model. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Outcome measures
| Measure |
Pertussis Case Group
n=106 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who met the pertussis diagnosis definition (laboratory confirmed pertussis, epidemiological linkage to a laboratory-confirmed case, clinically compatible illness), and who met the case infants inclusion criteria (resided in the catchment area on their cough onset date, were born in a hospital in their state of residence, had at least 37 weeks gestational age at birth, were neither adopted, nor in foster care and did not live in a residential care facility) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Control Group
n=180 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who did not have a pertussis diagnosis prior to the cough onset date and who met the inclusion criteria for control infants (were born on a hospital in their state of residence, were at least 37 weeks gestational age at birth, were neither adopted, nor in foster care, did not live in a residential care facility, were born at the same hospital as the case infant) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
|---|---|---|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (During Third Trimester of Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Unvaccinated
|
72 Participants
|
112 Participants
|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (During Third Trimester of Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated during third trimester
|
5 Participants
|
17 Participants
|
SECONDARY outcome
Timeframe: During the data collection period (from 1 January 2011 to 31 December 2014)Population: The analysis includes cases and at least one matched control born from mothers either unvaccinated or vaccinated with Boostrix. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Vaccine effectiveness at preventing pertussis occurrence in infants \< 2 months old is assessed by comparing the Boostrix immunization status before pregnancy, during first or second pregnancy trimester, after pregnancy in mothers of infant pertussis cases and matched controls. The association between maternal Boostrix vaccination and pertussis in infants was analyzed using conditional logistic regression. The multivariate analysis was performed to obtain the adjusted values. Covariates that were statistically significant in the univariate analysis or considered as clinically significant were included in the multivariable conditional logistic regression model. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Outcome measures
| Measure |
Pertussis Case Group
n=106 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who met the pertussis diagnosis definition (laboratory confirmed pertussis, epidemiological linkage to a laboratory-confirmed case, clinically compatible illness), and who met the case infants inclusion criteria (resided in the catchment area on their cough onset date, were born in a hospital in their state of residence, had at least 37 weeks gestational age at birth, were neither adopted, nor in foster care and did not live in a residential care facility) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Control Group
n=180 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who did not have a pertussis diagnosis prior to the cough onset date and who met the inclusion criteria for control infants (were born on a hospital in their state of residence, were at least 37 weeks gestational age at birth, were neither adopted, nor in foster care, did not live in a residential care facility, were born at the same hospital as the case infant) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
|---|---|---|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (Before Pregnancy, During First or Second Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Unvaccinated
|
72 Participants
|
112 Participants
|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (Before Pregnancy, During First or Second Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, before pregnancy
|
1 Participants
|
4 Participants
|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (Before Pregnancy, During First or Second Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, during first or second trimester
|
1 Participants
|
6 Participants
|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (Before Pregnancy, During First or Second Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, after pregnancy
|
27 Participants
|
41 Participants
|
SECONDARY outcome
Timeframe: During the data collection period (from 1 January 2011 to 31 December 2014)Population: The analysis includes cases and at least one matched control born from mothers either unvaccinated or vaccinated with Boostrix. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Vaccine effectiveness at preventing pertussis occurrence in infants \< 2 months old is assessed by comparing the Boostrix immunization status during pregnancy in mothers of infant pertussis cases and matched controls. The association between maternal Boostrix vaccination and pertussis in infants was analyzed using conditional logistic regression. The multivariate analysis was performed to obtain the adjusted values. Covariates that were statistically significant in the univariate analysis or considered as clinically significant were included in the multivariable conditional logistic regression model. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Outcome measures
| Measure |
Pertussis Case Group
n=106 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who met the pertussis diagnosis definition (laboratory confirmed pertussis, epidemiological linkage to a laboratory-confirmed case, clinically compatible illness), and who met the case infants inclusion criteria (resided in the catchment area on their cough onset date, were born in a hospital in their state of residence, had at least 37 weeks gestational age at birth, were neither adopted, nor in foster care and did not live in a residential care facility) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Control Group
n=180 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who did not have a pertussis diagnosis prior to the cough onset date and who met the inclusion criteria for control infants (were born on a hospital in their state of residence, were at least 37 weeks gestational age at birth, were neither adopted, nor in foster care, did not live in a residential care facility, were born at the same hospital as the case infant) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
|---|---|---|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (During First, Second or Third Trimester) or Not Exposed to Any Tdap Vaccine During Pregnancy
Unvaccinated
|
72 Participants
|
112 Participants
|
|
Number of Pertussis Cases and Matched Controls Among Infants Born to Mothers Vaccinated With Boostrix Vaccine (During First, Second or Third Trimester) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, during pregnancy (Any trimester)
|
6 Participants
|
23 Participants
|
SECONDARY outcome
Timeframe: During the data collection period (from 1 January 2011 to 31 December 2014)Population: The analysis includes cases leading to hospitalization and at least one matched control born from mothers either unvaccinated or vaccinated with Boostrix. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Vaccine effectiveness at preventing pertussis occurrence leading to hospitalization in infants \< 2 months old is assessed by comparing the Boostrix immunization status before pregnancy, during first or second, third trimester, after pregnancy in mothers of infant pertussis cases and matched controls. The association between maternal Boostrix vaccination and pertussis in infants was analyzed using conditional logistic regression. The multivariate analysis was performed to obtain the adjusted values. Covariates that were statistically significant in the univariate analysis or considered as clinically significant were included in the multivariable conditional logistic regression model. Subjects with missing or unknown values, if any, for at least one of the risk factors were excluded from the model.
Outcome measures
| Measure |
Pertussis Case Group
n=69 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who met the pertussis diagnosis definition (laboratory confirmed pertussis, epidemiological linkage to a laboratory-confirmed case, clinically compatible illness), and who met the case infants inclusion criteria (resided in the catchment area on their cough onset date, were born in a hospital in their state of residence, had at least 37 weeks gestational age at birth, were neither adopted, nor in foster care and did not live in a residential care facility) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
Control Group
n=121 Participants
Infant subjects of at least 2 days old and less than (\<) 2 months old, who did not have a pertussis diagnosis prior to the cough onset date and who met the inclusion criteria for control infants (were born on a hospital in their state of residence, were at least 37 weeks gestational age at birth, were neither adopted, nor in foster care, did not live in a residential care facility, were born at the same hospital as the case infant) This post-hoc analysis was limited to cases and controls whose mothers were either vaccinated with Boostrix or did not receive any Tdap vaccine. Cases with no remaining matched control were also excluded from the analysis and vice versa.
|
|---|---|---|
|
Number of Pertussis Cases Leading to Hospitalization and Matched Controls in Infants Born to Mothers Vaccinated With Boostrix (Before Pregnancy, During First or Second, Third Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Unvaccinated
|
49 Participants
|
78 Participants
|
|
Number of Pertussis Cases Leading to Hospitalization and Matched Controls in Infants Born to Mothers Vaccinated With Boostrix (Before Pregnancy, During First or Second, Third Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, before pregnancy
|
1 Participants
|
2 Participants
|
|
Number of Pertussis Cases Leading to Hospitalization and Matched Controls in Infants Born to Mothers Vaccinated With Boostrix (Before Pregnancy, During First or Second, Third Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, during first or second trimester
|
0 Participants
|
5 Participants
|
|
Number of Pertussis Cases Leading to Hospitalization and Matched Controls in Infants Born to Mothers Vaccinated With Boostrix (Before Pregnancy, During First or Second, Third Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, during third trimester
|
3 Participants
|
11 Participants
|
|
Number of Pertussis Cases Leading to Hospitalization and Matched Controls in Infants Born to Mothers Vaccinated With Boostrix (Before Pregnancy, During First or Second, Third Trimester, After Pregnancy) or Not Exposed to Any Tdap Vaccine During Pregnancy
Vaccinated, after pregnancy
|
16 Participants
|
25 Participants
|
Adverse Events
Pertussis Case Group
Control Group
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee GSK agreements may vary with individual investigators, but will not prohibit any investigator from publishing. GSK supports the publication of results from all centers of a multi-center trial but requests that reports based on single site data not precede the primary publication of the entire clinical trial.
- Publication restrictions are in place
Restriction type: OTHER