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
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- GlaxoSmithKline
- Enrollment
- 65,783
- Locations
- 1
- Primary Endpoint
- 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
Study Overview
Brief Summary
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.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Retrospective
Eligibility Criteria
- Sex
- Female
- Accepts Healthy Volunteers
- Yes
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).
Exclusion Criteria
- Not provided
Outcomes
Primary Outcomes
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.
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.
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.
Secondary Outcomes
- 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(From birth through 6 months of age)
- 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(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 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(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 Persons) of Women Adverse Events Presented for Exposed Cohort Women-before 1st Day of 27th Week of Pregnancy Group(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)
- Incidence Rate (Per 1000 Person-years) of Women Adverse Events for Exposed Cohort Women-before 1st Day of 27th Week of Pregnancy Group(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)
- Incidence Rate (Per 1000 Persons) of Infant Adverse Events for Exposed Cohort Infants-before 1st Day of 27th Week of Pregnancy Group(From birth through 6 months of age)