Acute upper respiratory infection; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 24-Jan-2020, concerning a 25-year-old, female pregnant subject of body weight: 260 lbs, height: 64.8 inches and body mass index (BMI): 43.5 enrolled in a prospective observational safety study.  The subject's medical history included bicornuate uterus, obesity, asthma and morning sickness. The subject's risk factors included maternal grandfather malignant tumor of colon, maternal aunt malignant tumor of ovary and mother multiple myeloma.  The subject's concomitant medications included Proair HFA (salbutamol sulfate) and Flonase (fluticasone propionate) for asthma, prenatal vitamins (unspecified vitamins and minerals) as obstetrics supplement, Diclegis (doxylamine succinate, pyridoxine hydrochloride) for morning sickness and progesterone micronized for an unknown indication.  The subject's obstetrical history included four previous pregnancies with three previous spontaneous abortions and one previous preterm live birth. The subject had no history of offspring with major congenital malformation (MCM) and no relevant maternal and paternal medical history with MCMs. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was 14-May-2019. The subject's estimated delivery date (EDD) was on 18-Feb-2020 and corrected estimated date of delivery (CEDD) were on 25-Feb-2020. The type of pregnancy was singleton and it was complicated with bicornuate uterus.  On 04-Oct-2019, at gestational age of 20 weeks, the subject was administered with Flucelvax QIV (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 261727, dose: 0.5 ml, anatomical location, route of administration and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for influenza immunisation.   On the same day, the subject underwent anatomy ultrasound and no MCM was noted.  On 06-Dec-2019, the subject was administered TDAP [diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid, dose: 0.5 ml, route of administration: intramuscular, anatomical location, batch number and expiration date: not reported] as vaccine.  On 20-Dec-2019, 2 months 16 days after vaccination, the subject developed acute upper respiratory infection. The patient was treated with cefpodoxime at dose of 200 mg, every 12 hours one tablet, orally, from 20-Dec-2019 to 25-Dec-2019.  On 25-Dec-2019, the outcome for the event of acute upper respiratory infection was resolved.  Per company, the event of acute upper respiratory infection was considered as serious due to the criterion of medical significance.  The reporter did not provide causality assessment to Flucelvax QIV.  Company Comment: The subject experienced upper respiratory tract infection after vaccination with the suspect product, Flucelvax QIV. Reportedly, vaccination occurred during pregnancy at 20 weeks of gestation. Chronology is plausible. Medical history of asthma, obesity (body mass index: 43.5) and pregnant state may provide alternative aetiology for the event. Causality is also confounded with co-suspect product Tdap (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) and multiple concomitant medications. Vaccine exposure during pregnancy is assessed as not related per company's conventions. Causality between suspect product and the event upper respiratory tract infection is assessed as not related due to biological implausibility.; Sender's Comments: The subject experienced upper respiratory tract infection after vaccination with the suspect product, Flucelvax QIV. Reportedly, vaccination occurred during pregnancy at 20 weeks of gestation. Chronology is plausible. Medical history of asthma, obesity (body mass index: 43.5) and pregnant state may provide alternative aetiology for the event. Causality is also confounded with co-suspect product Tdap (diphtheria vaccine toxoid, pertussis vaccine acellular, tetanus vaccine toxoid) and multiple concomitant medications. Vaccine exposure during pregnancy is assessed as not related per company's conventions. Causality between suspect product and the event upper respiratory tract infection is assessed as not related due to biological implausibility.