This retrospective pregnancy case was reported in a literature article and described the occurrence of pertussis in a infant. The mother received dTpa vaccine for prophylaxis. After 26 weeks of gestational age, the infant was born via unknown delivery method. The mother's last menstrual period was unknown and estimated date of delivery was unknown. The subject's mother received the dTpa vaccine during pregnancy (trimester unknown). The pregnancy resulted in a live neonate with no apparent congenital anomaly. Unknown time after the mother's vaccination with dTpa vaccine, the infant was diagnosed with pertussis. Serious criteria included hospitalization and GSK medically significant. Additional event(s) included fetal exposure during pregnancy. The outcome of pertussis was unknown. The outcome(s) of the additional event(s) included fetal exposure during pregnancy (unknown). The investigator considered that there was a reasonable possibility that the pertussis may have been caused by dTpa vaccine. Relevant Tests: Laboratory test was performed between June 2010 and December 2014 Diagnostic results (unless otherwise stated, normal values were not provided): On an unknown date, Bordetella test result was positive unknown. Additional information was provided. This retrospective pregnancy case was reported in a literature article and described the occurrence of pertussis infection in an infant aged between 6 month and 18 months of unspecified gender whose mother was vaccinated with unspecified Tdap vaccine (manufacturer unknown) during pregnancy (trimester unknown) for prophylaxis. This case corresponds to table 3 in this literature article. The patient was a part of the observational cohort of pregnant women and their infants delivered between June 2010 and December 2014 and determine the clinical effectiveness of prenatal Tdap in the prevention of infant pertussis, and to understand if effectiveness varies by gestational age at Tdap administration. Further, the study examined the rates of pertussis after the age of 6 months (the recommended age at primary DTaP series completion), to determine whether the immunologic finding of blunting by maternal antibodies has clinical relevance. It was reported that the patient's mother had first and singleton delivery. The mother's last menstrual period date and estimated date of delivery was unknown. No information on patient's medical history or concomitant medication or concurrent condition was provided. On an unspecified date during pregnancy, the patient's mother was vaccinated with unspecified Tdap vaccine (administration route and site unspecified, dosage unknown; batch number not provided). Subsequently, the foetus was exposed to vaccination in utero during pregnancy. The maternal age of vaccination was not provided. [It was reported that out of 90,445 mother-infant pairs by receipt of maternal Tdap prenatal, 75,556 received all DTaP on time]. On an unspecified date between June 2010 and December 2014, an unknown period after vaccination, the patient was born with unspecified delivery after 26 weeks of gestational age. In this study, infants were followed from day 7 post-delivery up to age 18 months for evidence of pertussis. The patient developed pertussis infection. It was reported that the patient was among inpatient pertussis cases. In this study, inpatient-only pertussis included only inpatient pertussis diagnoses. Diagnosis codes for hospital claims are assigned on hospital discharge; laboratory tests were performed during the hospitalization would commonly be completed prior to patient discharge, and therefore, the hospital physician would have this information prior to assigning a diagnosis code for the hospitalisation. This case has been considered serious due to hospitalisation. Treatment was unknown. The outcome of the event was not provided. The author did not comment on the relationship between the event of pertussis infection and unspecified Tdap vaccine. The author concluded, "Prenatal Tdap provided a substantial reduction in infant pertussis during the period of life with the highest pertussis burden. Increasing use of Tdap in pregnancy would be anticipated to reverse the current trends of pertussis incidence among infants in a specific country". Lab Comments: Laboratory test was performed between June 2010 and December 2014.