Preterm premature rupture of membranes (PPROM) at 21 weeks; Herpes Simplex Virus 1 (cold sores); Herpes Simplex Virus 1 (cold sores); Vaccine exposure during pregnancy; Nausea; This is an observational study case, reported by other health professional and initially received on 09-Dec-2019, concerning a 31-year-old pregnant, female subject (of body weight 131 lbs, height 59 inches and body mass index (BMI) 26.5,  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 current medical condition included increased BMI and high risk pregnancy.  The subject's concomitant medications included Makena (hydroxyprogesterone caproate) for high risk pregnancy and Prenatal vitamin (unspecified minerals and vitamins) as vitamin.  The subject's obstetrical history noted four previous pregnancies - three previous preterm live births and one elective abortion. Pregnancy outcome of third pregnancy included birth defect reported as placental abruption at 32 weeks and baby passed eight minutes post-delivery (neonatal demise). The subject had no history of offspring with major congenital malformation (MCM). Also, the subject had maternal history with MCM that included sister with Down's syndrome. The subject had no paternal history with MCM. The subject did not use tobacco, alcohol or illicit drugs during pregnancy.  The subject's last menstrual period (LMP) date was 03-Aug-2019. The subject's estimated date of delivery (EDD) and corrected estimated date of delivery (CEDD) were both reported as 09-May-2020. The type of pregnancy was singleton.   On 14-Oct-2019, at gestational age of 10 weeks  (calculated per LMP), the subject was administered Flucelvax QIV (Flu Vaccine Cell Subunit QIV NVD) [[nfluenza vaccine, subunit influenza virus vaccine polyvalent, batch number: 261727, 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 developed nausea and started treatment with one tablet of Bonjesta (doxylamine succinate, pyridoxine hydrochloride), administered orally, twice a day.  On 28-Oct-2019, the subject underwent first trimester screen and nuchal translucency. No MCM was noted.  On 25-Nov-2019, the subject underwent second trimester screen and maternal serum alpha fetoprotein (MSAFP / serum markers). No MCM was noted.  On 16-Dec-2019, the subject underwent anatomy ultrasound and no MCM was noted.  On 30-Dec-2019, two months and sixteen days after vaccination, the subject developed herpes simplex virus 1 (cold sores) and started treatment with Valtrex (valaciclovir hydrochloride) at dose of 500 mg, administered orally, every day.  On an unspecified date, 11 weeks after vaccination, the subject experienced preterm premature rupture of membranes (PPROM) at gestational age of 21 weeks. The subject was transferred care to Maternal-Fetal Medicine due to this event.  At the time of follow up, the subject did not recover from the events of nausea and herpes simplex type 1 (cold sores), while the outcome of PPROM was unknown.  The event of PPROM was considered serious due to the criteria of hospitalization and medical significance.  The reporter did not provide a causality assessment to Flucelvax QIV.  Follow up information received from other health professional on 16-Jan-2020: New event of herpes simplex type 1 (cold sores) added. Treatment medications updated with Valtrex. Lab data updated (on 25-Nov-2019 and on 16-Dec-2019). Narrative amended accordingly.  Follow up information received from other health professional on 07-Jul-2020: New event of PPROM at 21 weeks was added and case was upgraded from non-serious to serious. Narrative was amended accordingly.  Company comment: The subject experienced Herpes simplex and oral herpes two months and sixteen days after vaccination with the suspect product, Flucelvax QIVc. The subject also experienced nausea on the same day after vaccination and preterm premature rupture of membranes (PPROM) 11 weeks after vaccination. Reportedly, vaccination occurred during pregnancy at 14 weeks of gestation. Chronology is plausible only for the event of nausea. Medical history of increased body mass index (26.5) and high-risk pregnancy may provide alternative aetiology for the events. Causality is also confounded by therapy with concomitant medication Makena (hydroxyprogesterone caproate). Vaccine exposure during pregnancy is assessed as not related per company's conventions. Causality between suspect product and the events of Herpes simplex and oral herpes is not related. Causality for nausea is assessed as possibly related.; Sender's Comments: The subject experienced Herpes simplex and oral herpes two months and sixteen days after vaccination with the suspect product, Flucelvax QIVc. The subject also experienced nausea on the same day after vaccination and preterm premature rupture of membranes (PPROM) 11 weeks after vaccination. Reportedly, vaccination occurred during pregnancy at 10 weeks of gestation. Chronology is plausible for the event of nausea. Medical history of increased body mass index (26.5) and high-risk pregnancy may provide alternative aetiology for the events. Causality is also confounded by therapy with concomitant medication Makena (hydroxyprogesterone caproate). Vaccine exposure during pregnancy is assessed as not related per company's conventions. Causality between suspect product and the events of Herpes simplex and oral herpes is not related. Causality for nausea is assessed as possibly related.