Effectiveness of Maternal Immunization With Boostrix at Preventing Pertussis Among Infants <2 Months Old in the United States

Effectiveness of Maternal Immunization With Boostrix at Preventing Pertussis Among Infants <2 Months Old in the United States: Analysis of a Dataset From a Case-control Study

The purpose of this study is to estimate the effectiveness of maternal immunization with Boostrix at preventing pertussis in infants in the United States.

Inclusion Criteria:

Inclusion criteria for case infants:

• Case infants were eligible for the enrolment if they:
• were at least 2 days old and < 2 months old on the cough onset date
• resided in the catchment area on their cough onset date
• were born in a hospital in their state of residence
• were ≥37 weeks' gestational age at birth
• were neither adopted nor in foster care
• did not live in a residential care facility

Inclusion criteria for control infants:

• Control infants were eligible for the enrolment if they:
• were at least 2 days old and <2 months old on the case infant's cough onset date
• were born in a hospital in their state of residence
• were ≥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

did not have pertussis diagnosis prior to the cough onset date of the corresponding case infant

Exclusion Criteria:

• Infants (case and controls) whose mothers have received Adacel or mothers without brand information available, as well as controls who were matched to a case whose mother received Adacel or mothers without brand information available, will be excluded from the analysis of the effectiveness of vaccination with Boostrix.