Exposure to influenza virus; Dysfunction of Eustachian tube; Acute otitis media; Vaccine exposure during pregnancy; This is an observational study case, initially received from other health professional on 09-Dec-2019, concerning a 32-year-old female pregnant subject of body weight 120 lbs, height 63 inches and body mass index (BMI) 21.3, enrolled in a prospective observational safety study.    The subject's medical history included anxiety, depression, nausea and abnormal thyroid hormone.   The subject's concomitant medications included Bonjesta (doxylamine succinate, pyridoxine hydrochloride) for nausea, levothyroxine sodium for abnormal thyroid hormone and Vitafol (ferrous fumarate, folic acid, unspecified minerals and unspecified vitamins) as vitamin.  The subject's obstetrical history included three previous pregnancies with one spontaneous abortion and two full term live births with no birth defects. The subject had no history of offspring with major congenital malformation (MCM). Also, the subject had no maternal or paternal history with MCMs. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.   The subject's last menstrual period (LMP) date was reported as 12-Aug-2019. The subject's estimated date of delivery (EDD) was reported as 18-May-2020, while corrected estimated date of delivery (CEDD) was reported as 28-May-2020. The type of pregnancy was singleton.   On 18-Oct-2019, the subject underwent ultrasound and no MCMs were noted.  On 07-Nov-2019, at approximately 12 weeks of gestation, the subject was administered Flucelvax QIVc (Flu Vaccine Cell Subunit QIV NVD) [influenza vaccine, subunit influenza virus vaccine polyvalent; batch number: 261223, dose: 0.5 mL, route of administration, anatomical location and expiration date: not reported] (explicitly coded as 'Vaccine exposure during pregnancy') for an influenza immunisation.   On 13-Nov-2019, six days after vaccination, the subject experienced acute otitis media. The subject was treated with amoxicillin at the dose of 500 mg, twice daily, orally.  On 18-Nov-2019, 11 days after vaccination, the subject developed dysfunction of the Eustachian tube and received treatment medication Medrol (methylprednisolone) at the dose of 4 mg, as directed, orally. On the same day, the subject recovered from the event of acute otitis media and stopped treatment with amoxicillin. The subject also underwent first trimester screen and nuchal translucency and no MCMs were noted.  On 18-Dec-2019, the subject underwent second trimester screen and maternal serum alpha fetoprotein screening (MSAFP). No MCMs were noted.  On 26-Dec-2019, the subject was exposed to influenza virus and received treatment medication Tamiflu (oseltamivir phosphate) at the dose of 75 mg, daily, orally.  On 05-Jan-2020, the subject stopped treatment with Tamiflu.  On 06-Jan-2020, the subject underwent anatomy ultrasound and no MCMs were noted.  At the time of this report, the subject did not recover from the event of dysfunction of the Eustachian tube, while the outcome for the event of exposure to communicable disease' was not reported.  The event of 'exposure to influenza virus' was assessed by the Company as serious and medically significant. The events of acute otitis media, dysfunction of Eustachian tube and vaccine exposure during pregnancy were assessed as non-serious.  The reporter did not provide causality assessment to Flucelvax QIVc.  Follow up was received from other health professional on 11-Feb-2020: Additional prenatal tests were provided. Event of exposure to influenza virus and treatment medication Tamiflu were added. Narrative was amended accordingly.  Company Comment: The subject experienced otitis media acute, Eustachian tube dysfunction and exposure to influenza virus after vaccination with the suspect product, Flucelvax QIV. Reportedly, vaccination occurred during pregnancy at 12 weeks of gestation. Medical history of abnormal thyroid hormone and pregnant state may have also contributed to development of the events. Causality is also confounded with multiple concomitant medications. Vaccine exposure during pregnancy and exposure to influenza virus are assessed as not related. Causality between suspect product and other events is assessed as possibly related (defaults to 'related' causality for reporting purposes).; Sender's Comments: The subject experienced otitis media acute, Eustachian tube dysfunction and exposure to influenza virus after vaccination with the suspect product, Flucelvax QIV. Reportedly, vaccination occurred during pregnancy at 12 weeks of gestation. Medical history of abnormal thyroid hormone and pregnant state may have also contributed to development of the events. Causality is also confounded with multiple concomitant medications. Vaccine exposure during pregnancy and exposure to influenza virus are assessed as not related. Causality between suspect product and other events is assessed as possibly related (defaults to 'related' causality for reporting purposes).