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OpenTrials
Completed

NCT Number: NCT03463577

The Safety of Boostrix Following Routine Immunization of Pregnant Women

The purpose of this study was to assess the safety of Boostrix administered on or after the first day of the 27th week of pregnancy by conducting a post-marketing study that provided safety information to the public and healthcare providers. This was one of the largest cohorts of pregnant women vaccinated with Boostrix in the U.S. Through partnership between Kaiser Permanente Southern California (KPSC) and the sponsor, GlaxoSmithKline (GSK), information about the safety of maternal vaccination with Boostrix and maternal and infant adverse events (AEs) in a community setting was gained.

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Key information

Sex eligibility

Female

Study type

Observational

Primary location

GSK Investigational Site

Pasadena, California, 91101, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Pregnant women with prenatal care and continuous membership (allowing up to a 31-day gap) at KPSC between the 1st day of the 27th week of pregnancy and the index (vaccination) date.
  • Exposed cohort (from the 27th week of gestation): Pregnant women vaccinated with Boostrix on or after the 1st day of the 27th week of pregnancy; who were not vaccinated with any other Tdap vaccine at any other time during the pregnancy in scope of this study.
  • Unexposed cohort: Women matched to the exposed cohort and pregnant sometime during the approximate estimated period between January 1, 2012-December 31, 2014 and did not receive any Tdap vaccine during the pregnancy in scope of this study.

For the analysis of congenital anomalies among live births, at birth and through six months of age, the following additional inclusion criteria for infants will be applied:

  • Live born
  • Born in KPSC hospitals

Note: Pregnant women vaccinated with Boostrix during pregnancy before the 27th week of gestation, with membership at the date of vaccination, and who were not vaccinated with any other Tdap vaccine at any other time during the pregnancy in scope of this study will be part of a descriptive analysis (secondary objective).

Treatment and study plan

Safety assessment following routine immunization with Boostrix

Other

Subject-level data was collected for pregnant women and their infants through the Electronic Health Records.

Primary outcomes

  1. Incidence Rate (Per 1000 Person-years) of Pre-specified Maternal Adverse Events for Exposed Cohort women-on or After 1st Day of 27th Week of Pregnancy and Unexposed Historical Cohort-women Groups

    Time frame: From date of Boostrix vaccination (Exposed cohort women-on or after 1st day of 27th week of pregnancy) or from an index date (Unexposed historical cohort women) until end of enrollment or pregnancy, whichever came first, up to 13 weeks

    The incidence rate (per 1000) of maternal adverse events was calculated as the total number of adverse events in the numerator and the total person-years at risk in the denominator. Every unexposed woman was assigned an index date that is determined by the number of days from pregnancy start to the Boostrix vaccination date of her matched exposed woman. The same number of days calculated in the exposed woman was added to the pregnancy start of the unexposed woman to identify her index date. The pre-specified maternal adverse events assessed were pre-eclampsia and eclampsia; Intra-uterine infections.

  2. Incidence Rate (Per 1000 Persons) of Prespecified Maternal Adverse Events for Exposed Cohort women-on or After 1st Day of 27th Week of Pregnancy and Unexposed Historical Cohort Women Groups

    Time frame: From date of Boostrix vaccination (Exposed cohort women-on or after 1st day of 27th week of pregnancy) or from an index date (Unexposed historical cohort women) until end of enrollment or pregnancy, whichever came first, up to 13 weeks

    Incidence rate (per 1000) consisted of the total number of adverse events in the numerator and the number of persons at risk in the denominator. Every unexposed woman was assigned an index date that is determined by the number of days from pregnancy start to the Boostrix vaccination date of her matched exposed woman. The same number of days calculated in the exposed woman was added to the pregnancy start of the unexposed woman to identify her index date. The pre-specified maternal adverse event assessed was preterm delivery.

  3. Incidence Rate (Per 1000 Persons) of Pre-specified Infant Adverse Events for Exposed Cohort infants-on or After 1st Day of 27th Week of Pregnancy and Unexposed Historical Cohort Infants Groups

    Time frame: From birth through 6 months of age

    The incidence rate (per 1000) of adverse events was calculated as the total number of adverse events in the numerator and the total of persons at risk in the denominator. The pre-specified infant adverse event assessed was small for gestational age.

Secondary outcomes

  1. Incidence Rate (Per 1000 Person-years) of Other Maternal Adverse Events for Exposed Cohort women-on or After 1st Day of 27th Week of Pregnancy and Unexposed Historical Cohort Women Groups

    Time frame: From date of Boostrix vaccination (Exposed cohort women-on or after 1st day of 27th week of pregnancy) or from an index date (Unexposed historical cohort women) until end of enrollment or pregnancy, whichever came first, up to 13 weeks

    The incidence rate (per 1000) of other maternal adverse events was calculated as the total number of adverse events in the numerator and the total person-years at risk in the denominator. Every unexposed woman was assigned an index date that is determined by the number of days from pregnancy start to the Boostrix vaccination date of her matched exposed woman. The same number of days calculated in the exposed woman was added to the pregnancy start of the unexposed woman to identify her index date. The analysis was used for hypothesis generation/signal detection, hence without adjustment for multiple comparisons. The other maternal adverse events assessed were poor fetal growth; placental abruption; preterm pre-labor rupture of membranes; maternal death.

  2. Incidence Rate (Per 1000 Persons) of Other Maternal Adverse Events for Exposed Cohort women-on or After 1st Day of 27th Week of Pregnancy and Unexposed Historical Cohort Women Groups

    Time frame: From date of Boostrix vaccination (Exposed cohort women-on or after 1st day of 27th week of pregnancy) or from an index date (Unexposed historical cohort women) until end of enrollment or pregnancy, whichever came first, up to 13 weeks

    The incidence rate (per 1000) consisted of the total number of adverse events in the numerator and the number of persons at risk in the denominator. Every unexposed woman was assigned an index date that is determined by the number of days from pregnancy start to the Boostrix vaccination date of her matched exposed woman. The same number of days calculated in the exposed woman was added to the pregnancy start of the unexposed woman to identify her index date. The analysis was used for hypothesis generation/signal detection, hence without adjustment for multiple comparisons. The other maternal adverse events assessed were stillbirth/fetal death; stillbirth/fetal death with congenital anomalies; transfusion during delivery hospitalization.

  3. Incidence Rate (Per 1000 Persons) of Other Infant Adverse Events for Exposed Cohort infants-on or After 1st Day of 27th Week of Pregnancy and Unexposed Historical Cohort Infants Groups

    Time frame: From birth through 6 months of age

    The incidence rate (per 1000) of other infant adverse events was calculated as the total number of adverse events in the numerator and the total of persons at risk in the denominator. The analysis was used for hypothesis generation/signal detection, hence without adjustment for multiple comparisons. The other infant adverse events assessed were neonatal death, congenital anomalies of: nervous system; eye; ear, face, or neck; cardiovascular system; respiratory system; clefts; upper gastrointestinal system; lower gastrointestinal system; genital organs; renal system; musculoskeletal system; limb; integument; other and unspecified.

  4. Incidence Rate (Per 1000 Person-years) of Women Adverse Events for Exposed Cohort Women-before 1st Day of 27th Week of Pregnancy Group

    Time frame: For the Exposed cohort women-before 1st day of 27th week of pregnancy: from date of Boostrix vaccination until end of enrollment or pregnancy, whichever came first, up to 40 weeks

    The incidence rate (per 1000) was calculated as the total number of adverse events in the numerator and the total person-years at risk in the denominator. Due to the small sample size, the analysis of these women adverse events was descriptive. The women adverse events assessed were pre-eclampsia and eclampsia; intra-uterine infections; poor fetal growth; placental abruption; preterm pre-labor rupture of membranes; maternal death.

  5. Incidence Rate (Per 1000 Persons) of Women Adverse Events Presented for Exposed Cohort Women-before 1st Day of 27th Week of Pregnancy Group

    Time frame: For the Exposed cohort women-before 1st day of 27th week of pregnancy: from date of Boostrix vaccination until end of enrollment or pregnancy, whichever came first, up to 40 weeks

    The incidence rate (per 1000) consisted of the total number of adverse events in the numerator and the number of persons at risk in the denominator. The adverse events of this analysis include the adverse events presented in the above outcomes as well as spontaneous and therapeutic abortion with or without congenital anomalies in pregnant women vaccinated with Boostrix before the 27th week of gestation. Due to the small sample size, the analysis of these women adverse events was descriptive. The women adverse events assessed were stillbirth/fetal death; stillbirth/fetal death with congenital anomalies; spontaneous abortion; spontaneous abortion with congenital anomalies; therapeutic abortion; therapeutic abortion with congenital anomalies; transfusion during delivery hospitalization; preterm delivery.

  6. Incidence Rate (Per 1000 Persons) of Infant Adverse Events for Exposed Cohort Infants-before 1st Day of 27th Week of Pregnancy Group

    Time frame: From birth through 6 months of age

    The incidence rate (per 1000) was calculated as the total number of adverse events in the numerator and the total of persons at risk in the denominator. The adverse events of this analysis include adverse events presented in the above outcomes, among the infants whose mothers were vaccinated with Boostrix before the 27th week of gestation. Due to the small sample size, the analysis of these infant adverse events was descriptive. The infant adverse events assessed were: small for gestational age; neonatal death; congenital anomalies of: nervous system; eye; ear, face, or neck; cardiovascular system; respiratory system; clefts; upper gastrointestinal system; lower gastrointestinal system; genital organs; renal system; musculoskeletal system; limb; integument; other and unspecified.

Sponsors and collaborators

Lead sponsor

GlaxoSmithKline

Industry

Collaborators

  • Kaiser Permanente

Registry information

Official study title

An Observational, Retrospective Cohort Database Study to Assess the Safety of Boostrix (U.S. Formulation), a Reduced Tetanus, Diphtheria, Acellular Pertussis Vaccine (Tdap), Following Routine Immunization of Pregnant Women in the United States

Important dates

Study start
2018
Primary completion
2020
Study completion
2020
First posted
Mar 13, 2018
Registry last updated
May 18, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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