{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T11:58:11Z","timestamp":1783339091113,"version":"3.54.6"},"reference-count":39,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2022,9,23]],"date-time":"2022-09-23T00:00:00Z","timestamp":1663891200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Seqirus, Inc."}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Objective: To evaluate pregnancy and infant outcomes among persons immunized with a cell-based quadrivalent inactivated influenza vaccine (IIV4c) during routine pregnancy care. Design: Prospective observational cohort. Setting: US-based obstetrics\/gynecology clinics. Population: Pregnant persons. This US-based, prospective observational cohort study evaluated the safety of quadrivalent inactivated influenza vaccine (IIV4c; Flucelvax\u00ae Quad) in pregnant persons immunized over 3 influenza seasons between 2017 and 2020. Pregnant persons were immunized with IIV4c as part of routine care, after which their health care provides HCPs with all observational data to a single coordinating center. Follow-up data were collected at the end of the second trimester and\/or at the time of pregnancy outcome. A scientific advisory committee reviewed the data. Prevalence point estimates were reported with 95% confidence intervals (CIs). Pregnancy outcomes included: live birth, stillbirth, spontaneous abortion, elective termination, and maternal death. Infant outcomes included: preterm birth (&lt;37 weeks gestational age), low birth weight (&lt;2500 g), or major congenital malformations (MCMs). Of the 665 evaluable participants, 659 (99.1%) had a live birth. No stillbirths (0% [95% CI 0.0\u20130.6]), 4 spontaneous abortions (1.9% [0.5\u20134.8]), and 1 elective termination (0.5% [0.0\u20132.6]) were reported. Among 673 infants, 9.2% (upper 95% CI 11.5%) were born prematurely, 5.8% (upper 95% CI 7.6%) had low birth weight, and 1.9% (upper 95% CI 3.1%) were reported to have an MCM. No maternal deaths were reported. Of the 2 infants who died shortly after birth, one was adjudicated as not related to the vaccine; the other\u2019s cause could not be determined due to maternal loss to follow-up. The prevalence of adverse pregnancy outcomes or preterm birth, low birth weight, or MCMs in newborns was similar in persons vaccinated with IIV4c compared to the rates observed in US surveillance systems. The safety profile of IIV4c in pregnant persons is consistent with previously studied influenza vaccines.<\/jats:p>","DOI":"10.3390\/vaccines10101600","type":"journal-article","created":{"date-parts":[[2022,9,29]],"date-time":"2022-09-29T01:23:16Z","timestamp":1664414596000},"page":"1600","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Outcomes in Pregnant Persons Immunized with a Cell-Based Quadrivalent Inactivated Influenza Vaccine: A Prospective Observational Cohort Study"],"prefix":"10.3390","volume":"10","author":[{"given":"Christopher","family":"Robinson","sequence":"first","affiliation":[{"name":"Charleston Maternal Fetal Medicine, Mount Pleasant, SC 29485, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Josephine","family":"Van Boxmeer","sequence":"additional","affiliation":[{"name":"Seqirus Netherlands B.V., 1105 BJ Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hugh","family":"Tilson","sequence":"additional","affiliation":[{"name":"Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1351-4572","authenticated-orcid":false,"given":"Anthony","family":"Scialli","sequence":"additional","affiliation":[{"name":"Scialli Consulting LLC, Washington, DC 20008, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John A.","family":"Vanchiere","sequence":"additional","affiliation":[{"name":"Louisiana State University Health Science Center, Shreveport, LA 71106, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ellis","family":"Ides","sequence":"additional","affiliation":[{"name":"Seqirus Netherlands B.V., 1105 BJ Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daphne","family":"Sawlwin","sequence":"additional","affiliation":[{"name":"Seqirus Pty Ltd., Parkville, VIC 3052, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deborah","family":"Molrine","sequence":"additional","affiliation":[{"name":"Seqirus USA Inc., Cambridge, MA 02139, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew","family":"Hohenboken","sequence":"additional","affiliation":[{"name":"Seqirus USA Inc., Cambridge, MA 02139, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonathan","family":"Edelman","sequence":"additional","affiliation":[{"name":"Seqirus USA Inc., Summit, NJ 07901, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica D.","family":"Albano","sequence":"additional","affiliation":[{"name":"Syneos Health, Wilmington, NC 28403, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.15585\/mmwr.rr6908a1","article-title":"Prevention and control of seasonal influenza with vaccines: Recommendations of the advisory committee on immunization practices\u2014United States, 2020\u20132021 influenza season","volume":"69","author":"Grohskopf","year":"2020","journal-title":"MMWR Recomm. 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