Bacterial vaginosis; Yeast infection; Trichomoniasis; Chlamydia; Vaccine exposure during pregnancy; This is a serious observational study case initially received on 12-Jul-2019, concerning a 22-year-old adult female, pregnant subject enrolled in a prospective observational safety study on pregnancy outcomes in women immunized with seasonal cell culture influenza trivalent (TIVc) or quadrivalent (QIVc) vaccine during pregnancy.  The subject's obstetrical history noted that the subject had 2 previous pregnancy of full-term live births and no birth defects were reported. The subject had no history of offspring with major congenital malformation. Also, the subject had no maternal or paternal history with major congenital malformations. The subject did not have a prior history of use of tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was not reported. The type of pregnancy was singleton. On an unspecified date, the subject's pregnancy status was collected, and no pregnancy complications were noted.  The subject's concomitant medication included prenatal vitamins (minerals nos, vitamins nos) for pregnancy. On 24-Sep-2018, the subject underwent haemoglobin electrophoresis and no major congenital malformations were noted.  On 02-Oct-2018, at unknown weeks of gestation, the subject was administered Flu Vaccine Cell Subunit QIV NVD (influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 252664, dose, route of administration, anatomical location, batch number and expiry date: not reported) (explicitly coded as vaccine exposure during pregnancy) for an unknown indication.  On 05-Oct-2018, 3 days after vaccination, the subject developed chlamydial infection. On the same day, the subject was treated with Zithromax tablet (azithromycin, dose: 250 mg, frequency; reported as 4 tablets once) orally for chlamydial infection. On 08-Oct-2018, 6 days after vaccination, the subject developed bacterial vaginosis, yeast infection and trichomoniasis. On the same day, the subject was treated with Metrogel [metronidazole, dose: 0.75 percent, twice a day (bid)] vaginally for bacterial vaginosis and trichomoniasis and Diflucan pill (fluconazole, dose: 1 pill, frequency: once) orally for yeast infection. On 13-Oct-2018, the subject underwent ultrasound antenatal screening and no major congenital malformations were noted.    The outcome of the event chlamydial infection' was recovered on 15-Oct-2018 and the outcome of the events bacterial vaginosis, yeast infection and trichomoniasis was recovered on 18-Oct-2018.   The subject's corrected estimated date of delivery (CEDD) was reported as 18-Dec-2018.    at approximately 40.9 weeks gestation (as reported), the subject gave a live birth to a normal male neonate by caesarean method of delivery. The characteristics of the neonate included birth weight: 3856 grams, head circumference: 34.3 cm, length: 55.2 cm and appearance, pulse, grimace, activity, and respiration (APGAR) scores were 8 at one minute and 9 at five minutes). No major congenital malformations (MCMs) were identified at birth. There were no pregnancy complications noted.; Reporter's Comments: A 22-year-old pregnant subject experienced chlamydial infection 3 days post vaccination with Flu vaccine cell subunit QIV, and bacterial vaginosis, yeast infection and trichomoniasis, 6 days post vaccination. Considering the infectious aetiology of the events and inactivated nature of the suspect vaccine, the causality was assessed as not related to suspect vaccine. The company assessed the case as serious (medically significant).