{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T12:47:28Z","timestamp":1782910048466,"version":"3.54.5"},"reference-count":48,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Following the COVID-19 pandemic, hybrid immunity, arising from a combination of SARS-CoV-2 infection and vaccination, is widespread across populations, yet the dynamics of maternal antibody transfer to neonates in this context are not fully characterized.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted a cohort study of 117 pregnant women, assessing IgG antibodies against SARS-CoV-2 nucleoprotein and receptor-binding domain (RBD) in maternal, umbilical cord, and neonatal blood at delivery.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Using ELISA and pseudo virus neutralization assays, we found that 95% of mothers had detectable IgG, with 87% of neonates acquiring antibodies trans placentally. Hybrid immunity, detected in 65.5% of mothers, was associated with higher anti-RBD IgG levels in newborns compared to natural or vaccination-induced immunity alone. Neutralizing antibodies correlated positively with IgG titers, with umbilical cord samples showing the highest neutralization capacity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>These findings suggest that combined natural infection and vaccination in mothers enhance passive immunity in neonates, potentially improving early-life protection against SARS-CoV-2.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fped.2026.1824042","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T12:02:19Z","timestamp":1782907339000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Maternal immunization status and SARS-CoV-2 antibody transfer to neonates at birth"],"prefix":"10.3389","volume":"14","author":[{"given":"J.","family":"G\u00f3mez-Carballo","sequence":"first","affiliation":[{"name":"Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Aut\u00f3noma de Yucat\u00e1n","place":["M\u00e9rida, M\u00e9xico"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R.","family":"Gonz\u00e1lez-Losa","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Aut\u00f3noma de Yucat\u00e1n","place":["M\u00e9rida, M\u00e9xico"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"Conde-Ferr\u00e1ez","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Aut\u00f3noma de Yucat\u00e1n","place":["M\u00e9rida, M\u00e9xico"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C.","family":"Cen-Baas","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Aut\u00f3noma de Yucat\u00e1n","place":["M\u00e9rida, M\u00e9xico"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N.","family":"Kantun-Moreno","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Aut\u00f3noma de Yucat\u00e1n","place":["M\u00e9rida, M\u00e9xico"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H.","family":"Puerta-Guardo","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Aut\u00f3noma de Yucat\u00e1n","place":["M\u00e9rida, M\u00e9xico"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. 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