{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T05:21:08Z","timestamp":1788240068640,"version":"build-2803163510"},"reference-count":33,"publisher":"American Academy of Pediatrics (AAP)","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,5,1]]},"abstract":"<jats:sec>\n                    <jats:title\/>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>SARS-CoV-2 vaccination during pregnancy reduces COVID-19 risk in infancy. Whether maternal vaccination before pregnancy similarly protects infants against COVID-19 is unknown.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>We examined the effectiveness of maternal messenger RNA SARS-CoV-2 vaccination before and during pregnancy in preventing COVID-19 in infants aged 0\u20136\u00a0months born between July 1, 2021, and June 30, 2023, at Kaiser Permanente Northern California. Maternal vaccination status was categorized as vaccinated during pregnancy, during a prepregnancy interval (0\u2013&amp;lt;3, 3\u2013&amp;lt;6, 6\u201312, and &amp;gt;12\u00a0months prepregnancy), or unvaccinated. Secondary analyses examined the effectiveness of vaccination by trimester. COVID-19 was defined by positive SARS-CoV-2 PCR result or diagnostic code, and COVID-19\u2013related hospitalizations were confirmed by medical record review. Vaccine effectiveness (VE) was examined by Cox regression models adjusted for maternal and infant characteristics, calculated as (1\u2009\u2212\u2009hazard ratio)\u2009\u00d7\u2009100%.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>Among 78\u2009644 infants, 3648 (4.6%) had COVID-19 infection and 76 (0.1%) experienced COVID-19\u2013related hospitalization before age 6\u00a0months. For the 4 prepregnancy vaccination intervals, estimates for VE against COVID-19 infection ranged from \u221214.9% (95% CI, \u221232.8% to 0.5%) for less than 3\u00a0months prepregnancy to 23.6% (\u221214.3% to 49%) for more than 12\u00a0months prepregnancy. VE anytime during pregnancy was 7.5% (\u22122% to 16.2%) against infant COVID-19 infection and 52.9% (11.1%\u201375.1%) against infant COVID-19\u2013related hospitalization. Effectiveness of third-trimester vaccination was 19.2% (8.6%\u201328.6%) against infant COVID-19 infection and 64.6% (12.3%\u201385.7%) against infant COVID-19\u2013related hospitalizations.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSION<\/jats:title>\n                    <jats:p>Maternal vaccination during the third trimester was protective against infant COVID-19 infections. Maternal vaccination during pregnancy, particularly during the third trimester, was effective against infant COVID-19\u2013related hospitalizations. Vaccination before pregnancy did not protect infants.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1542\/peds.2025-073000","type":"journal-article","created":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T00:03:06Z","timestamp":1776816186000},"source":"Crossref","is-referenced-by-count":1,"title":["SARS-CoV-2 Vaccination Before and During Pregnancy and Prevention of Infant COVID-19 Infection"],"prefix":"10.1542","volume":"157","author":[{"given":"Karen B.","family":"Jacobson","sequence":"first","affiliation":[{"name":"Kaiser Permanente Vaccine Study Center, Oakland, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maqdooda","family":"Merchant","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Vaccine Study Center, Oakland, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bruce","family":"Fireman","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Vaccine Study Center, Oakland, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicola P.","family":"Klein","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Vaccine Study Center, Oakland, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ousseny","family":"Zerbo","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Vaccine Study Center, Oakland, California"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"417","published-online":{"date-parts":[[2026,4,22]]},"reference":[{"issue":"1","key":"2026090101115778500_r1","doi-asserted-by":"crossref","first-page":"562","DOI":"10.1186\/s12884-024-06767-7","article-title":"The impact of COVID-19 infections on pregnancy outcomes in women","volume":"24","author":"Xu","year":"2024","journal-title":"BMC Pregnancy Childbirth."},{"issue":"45","key":"2026090101115778500_r2","doi-asserted-by":"crossref","first-page":"1442","DOI":"10.15585\/mmwr.mm7145a3","article-title":"COVID-19-associated hospitalizations among U.S. infants aged &lt;6\u00a0months - COVID-NET, 13 states, June 2021-August 2022","volume":"71","author":"Hamid","year":"2022","journal-title":"MMWR Morb Mortal Wkly Rep."},{"key":"2026090101115778500_r3","article-title":"2019 (COVID-19) Hospitalization Surveillance Network (COVID-NET)","author":"Coronavirus Disease"},{"issue":"5","key":"2026090101115778500_r4","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1001\/jama.2023.26945","article-title":"Neonatal outcomes after COVID-19 vaccination in pregnancy","volume":"331","author":"Norman","year":"2024","journal-title":"JAMA."},{"issue":"16","key":"2026090101115778500_r5","doi-asserted-by":"crossref","first-page":"1775","DOI":"10.3390\/diagnostics14161775","article-title":"Safety of COVID-19 vaccination in pregnancy: a systematic review","volume":"14","author":"Gerede","year":"2024","journal-title":"Diagnostics (Basel)."},{"key":"2026090101115778500_r6","doi-asserted-by":"crossref","first-page":"e071416","DOI":"10.1136\/bmj-2022-071416","article-title":"Risk of preterm birth, small for gestational age at birth, and stillbirth after covid-19 vaccination during pregnancy: population based retrospective cohort study","volume":"378","author":"Fell","year":"2022","journal-title":"BMJ."},{"issue":"15","key":"2026090101115778500_r7","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.1001\/jama.2022.3271","article-title":"Association of SARS-CoV-2 vaccination during pregnancy with pregnancy outcomes","volume":"327","author":"Magnus","year":"2022","journal-title":"JAMA."},{"issue":"6","key":"2026090101115778500_r8","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1097\/AOG.0000000000005583","article-title":"Obstetric complications and birth outcomes after antenatal coronavirus disease 2019 (COVID-19) vaccination","volume":"143","author":"Vesco","year":"2024","journal-title":"Obstet Gynecol."},{"issue":"8","key":"2026090101115778500_r9","doi-asserted-by":"crossref","first-page":"823","DOI":"10.1001\/jamapediatrics.2024.1917","article-title":"COVID-19 vaccination in the first trimester and major structural birth defects among live births","volume":"178","author":"Kharbanda","year":"2024","journal-title":"JAMA Pediatr."},{"issue":"8","key":"2026090101115778500_r10","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1001\/jama.2021.11035","article-title":"Association between BNT162b2 vaccination and incidence of SARS-CoV-2 infection in pregnant women","volume":"326","author":"Goldshtein","year":"2021","journal-title":"JAMA."},{"issue":"4","key":"2026090101115778500_r11","doi-asserted-by":"crossref","first-page":"100264","DOI":"10.1016\/j.xagr.2023.100264","article-title":"Effectiveness of COVID-19 vaccination during pregnancy by circulating viral variant","volume":"3","author":"Zerbo","year":"2023","journal-title":"AJOG Glob Rep."},{"issue":"9","key":"2026090101115778500_r12","doi-asserted-by":"crossref","first-page":"e2233273","DOI":"10.1001\/jamanetworkopen.2022.33273","article-title":"Estimation of COVID-19 mRNA vaccine effectiveness against medically attended COVID-19 in pregnancy during periods of delta and omicron variant predominance in the United States","volume":"5","author":"Schrag","year":"2022","journal-title":"JAMA Netw Open."},{"issue":"8","key":"2026090101115778500_r13","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1001\/jamainternmed.2022.2442","article-title":"Association of COVID-19 vaccination during pregnancy with incidence of SARS-CoV-2 infection in infants","volume":"182","author":"Carlsen","year":"2022","journal-title":"JAMA Intern Med."},{"issue":"2","key":"2026090101115778500_r14","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1056\/NEJMoa2204399","article-title":"Maternal vaccination and risk of hospitalization for Covid-19 among infants","volume":"387","author":"Halasa","year":"2022","journal-title":"N Engl J Med."},{"issue":"3","key":"2026090101115778500_r15","doi-asserted-by":"crossref","first-page":"e2023064252","DOI":"10.1542\/peds.2023-064252","article-title":"Maternal COVID-19 vaccination and prevention of symptomatic infection in infants","volume":"153","author":"Cardemil","year":"2024","journal-title":"Pediatrics."},{"issue":"1","key":"2026090101115778500_r16","doi-asserted-by":"crossref","first-page":"894","DOI":"10.1038\/s41467-023-36547-4","article-title":"Maternal SARS-CoV-2 vaccination and infant protection against SARS-CoV-2 during the first six months of life","volume":"14","author":"Zerbo","year":"2023","journal-title":"Nat Commun."},{"issue":"12","key":"2026090101115778500_r17","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.1001\/jamapediatrics.2023.4499","article-title":"Newborn and early infant outcomes following maternal COVID-19 vaccination during pregnancy","volume":"177","author":"Jorgensen","year":"2023","journal-title":"JAMA Pediatr."},{"issue":"1","key":"2026090101115778500_r18","doi-asserted-by":"crossref","first-page":"2846","DOI":"10.1038\/s41467-024-46694-x","article-title":"Maternal hybrid immunity and risk of infant COVID-19 hospitalizations: national case-control study in Israel","volume":"15","author":"Guedalia","year":"2024","journal-title":"Nat Commun."},{"issue":"1","key":"2026090101115778500_r19","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1186\/s12884-023-05926-6","article-title":"Serologic evolution and follow-up to IgG antibodies of infants born to mothers with gestational COVID","volume":"23","author":"Vigil-V\u00e1zquez","year":"2023","journal-title":"BMC Pregnancy Childbirth."},{"issue":"7","key":"2026090101115778500_r20","doi-asserted-by":"crossref","first-page":"e2323405","DOI":"10.1001\/jamanetworkopen.2023.23405","article-title":"Assessment of adverse reactions, antibody patterns, and 12-month outcomes in the mother-infant dyad after COVID-19 mRNA vaccination in pregnancy","volume":"6","author":"Cassidy","year":"2023","journal-title":"JAMA Netw Open."},{"issue":"1","key":"2026090101115778500_r21","doi-asserted-by":"crossref","first-page":"2403831","DOI":"10.1080\/21645515.2024.2403831","article-title":"Efficacy of vaccination during pregnancy in reducing the risk of SARS-CoV-2 infection in infants younger than 12\u00a0months. Puglia (Italy), 2021\u201323","volume":"20","author":"De Virgilio Suglia","year":"2024","journal-title":"Hum Vaccin Immunother."},{"issue":"11","key":"2026090101115778500_r22","doi-asserted-by":"crossref","first-page":"e2342475","DOI":"10.1001\/jamanetworkopen.2023.42475","article-title":"mRNA SARS-CoV-2 vaccination before vs during pregnancy and omicron infection among infants","volume":"6","author":"Goh","year":"2023","journal-title":"JAMA Netw Open."},{"issue":"1","key":"2026090101115778500_r23","doi-asserted-by":"crossref","first-page":"3571","DOI":"10.1038\/s41467-022-31169-8","article-title":"Maternal immune response and placental antibody transfer after COVID-19 vaccination across trimester and platforms","volume":"13","author":"Atyeo","year":"2022","journal-title":"Nat Commun."},{"issue":"1","key":"2026090101115778500_r24","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1038\/s41372-023-01843-w","article-title":"SARS-CoV-2 neutralizing antibody titers in maternal blood, umbilical cord blood, and breast milk","volume":"44","author":"Khalifeh","year":"2024","journal-title":"Journal of Perinatology."},{"key":"2026090101115778500_r25","doi-asserted-by":"crossref","first-page":"985646","DOI":"10.1155\/2012\/985646","article-title":"IgG placental transfer in healthy and pathological pregnancies","volume":"2012","author":"Palmeira","year":"2012","journal-title":"Clin Dev Immunol."},{"issue":"8","key":"2026090101115778500_r26","doi-asserted-by":"crossref","first-page":"e409","DOI":"10.1016\/S2666-7568(23)00099-5","article-title":"Effectiveness of previous infection-induced and vaccine-induced protection against hospitalisation due to omicron BA subvariants in older adults: a test-negative, case-control study in Quebec, Canada","volume":"4","author":"Carazo","year":"2023","journal-title":"Lancet Healthy Longev."},{"issue":"10","key":"2026090101115778500_r27","doi-asserted-by":"crossref","first-page":"1132","DOI":"10.3390\/vaccines12101132","article-title":"Maternal preconception COVID-19 vaccination and its protective effect on infants after a breakthrough infection during pregnancy","volume":"12","author":"Yang","year":"2024","journal-title":"Vaccines (Basel)."},{"issue":"1","key":"2026090101115778500_r28","first-page":"1","article-title":"Births: Final Data for 2023","volume":"75","author":"Osterman","year":"2025","journal-title":"National Vital Statistics Reports."},{"key":"2026090101115778500_r29","article-title":"COVID-19 vaccination for people who are pregnant or breastfeeding","author":"Centers for Disease Control and Prevention","year":"2024"},{"issue":"3","key":"2026090101115778500_r30","doi-asserted-by":"crossref","first-page":"e13596","DOI":"10.1111\/aji.13596","article-title":"Decreased severity of COVID-19 in vaccinated pregnant individuals during predominance of different SARS-CoV-2 variants","volume":"88","author":"Eid","year":"2022","journal-title":"Am J Reprod Immunol."},{"issue":"7","key":"2026090101115778500_r31","doi-asserted-by":"crossref","first-page":"100981","DOI":"10.1016\/j.ajogmf.2023.100981","article-title":"Analysis of placental pathology after COVID-19 by timing and severity of infection","volume":"5","author":"Corbetta-Rastelli","year":"2023","journal-title":"Am J Obstet Gynecol MFM."},{"issue":"5","key":"2026090101115778500_r32","doi-asserted-by":"crossref","first-page":"1107","DOI":"10.4269\/ajtmh.23-0801","article-title":"Gestational SARS-CoV-2 infection in a Ugandan birth cohort: high incidence, mild maternal disease, and evidence of association with transient infant stunting","volume":"111","author":"Jacobson","year":"2024","journal-title":"Am J Trop Med Hyg."},{"issue":"1","key":"2026090101115778500_r33","doi-asserted-by":"crossref","first-page":"24866","DOI":"10.1038\/s41598-024-76690-6","article-title":"The association of increased incidence of congenital heart disease in newborns with maternal COVID-19 infection during pregnancy","volume":"14","author":"Ren","year":"2024","journal-title":"Sci Rep."}],"container-title":["Pediatrics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/publications.aap.org\/pediatrics\/article-pdf\/doi\/10.1542\/peds.2025-073000\/1927371\/pediatrics.2025073000.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/publications.aap.org\/pediatrics\/article-pdf\/doi\/10.1542\/peds.2025-073000\/1927371\/pediatrics.2025073000.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T05:12:07Z","timestamp":1788239527000},"score":1,"resource":{"primary":{"URL":"https:\/\/publications.aap.org\/pediatrics\/article\/157\/5\/e2025073000\/207229\/SARS-CoV-2-Vaccination-Before-and-During-Pregnancy"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,22]]},"references-count":33,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,4,22]]},"published-print":{"date-parts":[[2026,5,1]]}},"URL":"https:\/\/doi.org\/10.1542\/peds.2025-073000","relation":{},"ISSN":["0031-4005","1098-4275"],"issn-type":[{"value":"0031-4005","type":"print"},{"value":"1098-4275","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,22]]},"article-number":"e2025073000"}}