Headache; Lower back pain; Trichomonas; Trichomoniasis; Atypical squamous cells of undetermined significance; Vaccine exposure during pregnancy; This is an observational study case initially received on 24-Jan-2020, concerning a 25-year-old female pregnant subject of body weight 226.8 lbs, height 66 inches and body mass index (BMI) 36.6, enrolled in a prospective observational safety study.  The subject's historical condition included cannabis abuse until unspecified date in 2019. The subject's current conditions included increased BMI, nausea since Nov-2019 and polycystic ovarian syndrome.   The subject's concomitant medication included Vitafol (folic acid) used as vitamin, Bonjesta (doxylamine succinate, pyridoxine hydrochloride) and ondansetron, both for nausea.  The subject's obstetrical history noted that the subject had one previous pregnancy of full-term live birth with no birth defects. The subject had no history of offspring with major congenital malformation (MCM). The subject's second cousin had sickle cell disease. The subject had no paternal history with MCM. The subject did not use alcohol during pregnancy. The subject used cigars and cannabis during pregnancy.  The subject's last menstrual period (LMP) date was on 07-Oct-2019. The subject's estimated date of delivery (EDD) and corrected estimated date of delivery (CEDD) were both reported as 13-Jul-2020. The type of pregnancy was singleton.   On 16-Dec-2019, at approximately 10 weeks of gestation (estimated from LMP), the subject was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD [influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 261228, dose: 0.5 mL, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for influenza immunisation.  On the same day, the subject underwent ultrasound and no MCMs were noted.  On 17-Dec-2019, one day after vaccination, the subject developed atypical squamous cells of undetermined significance reported as pregnancy complication.  On 02-Jan-2020, 17 days after vaccination, the subject developed trichomoniasis and started treatment with oral metronidazole, 500 mg administered twice a day.  On 07-Jan-2020, the subject underwent first trimester screen, nuchal translucency and ultrasound. There were no MCMs noted.  On 09-Jan-2020, the subject recovered from the event of 'trichomoniasis' and stopped treatment with oral metronidazole.  On 15-Jan-2020, 30 days after vaccination, the subject again developed trichomonas and started treatment with oral Flagyl (metronidazole), four tablets of 500 mg administered once per day.  On 29-Jan-2020, the subject underwent maternal serum alpha fetoprotein screening (MSAFP/serum markers) and second trimester screen. There were no MCMs noted.  On 19-Feb-2020, the subject underwent anatomy ultrasound and no MCMs were noted.  On 26-Feb-2020, two months and 10 days after vaccination, the subject developed lower back pain and started treatment with oral cyclobenzaprine, at a dose of 5 mg administered three times per day as needed.  On 23-Mar-2020, approximately three months after vaccination, the subject developed headache and started treatment oral Fioricet (butalbital, caffeine, paracetamol), one tablet administered four times per day as needed.  At the time of this report, the subject had not recovered from the events of 'atypical squamous cells of undetermined significance', 'trichomoniasis', 'low back pain', and 'headache'.   The event of atypical squamous cells of undetermined significance' was assessed as serious due to criteria of medically significance, per company.  The reporter did not provide causality assessment.   Follow up information received from other health professional on 25-Mar-2020: Laboratory analysis updated [laboratory tests performed on 07-Jan-2020, 29-Jan-2020 and 19-Feb-2020 added]; Treatment medications added [metronidazole, Flagyl, cyclobenzaprine and Fioricet]; Additional serious event [Atypical squamous cells of undetermined significance] and non-serious events added [trichomoniasis on 02-Jan-2020 and on 15-Jan-2020; lower back pain and headaches]. Narrative amended accordingly.  Company comment: Reportedly, the subject developed Cervical dysplasia one day after vaccination with the suspect product Flucelvax QIV, chronology is implausible. The patient also experienced Trichomoniasis 17 days and again 30 days post vaccination. The subject experienced back pain 2 months and headache 3 months post vaccination. Causality is compatible. However, causal role of vaccine is assessed as not related for Trichomoniasis, since subject's exposure to infective agent may provide more plausible alternative aetiology. Underlying medical history of increased BMI and pregnant state confound causality assessment for back pain and headache. The subject used cigars and cannabis during pregnancy. Causal role of vaccine is assessed as not related for cervical dysplasia, back pain and headache. Vaccine exposure during pregnancy is assessed as not related per company's conventions.; Sender's Comments: Reportedly, the subject developed Cervical dysplasia one day after vaccination with the suspect product Flucelvax QIV, chronology is implausible. The patient also experienced Trichomoniasis 17 days and again 30 days post vaccination. The subject experienced back pain 2 months and headache 3 months post vaccination. Causality is compatible. However, causal role of vaccine is assessed as not related for Trichomoniasis, since subject's exposure to infective agent may provide more plausible alternative aetiology. Underlying medical history of increased BMI and pregnant state confound causality assessment for back pain and headache. The subject used cigars and cannabis during pregnancy. Causal role of vaccine is assessed as not related for cervical dysplasia, back pain and headache. Vaccine exposure during pregnancy is assessed as not related per company's conventions.