{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T18:15:14Z","timestamp":1788372914468,"version":"build-2803163510"},"reference-count":37,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T00:00:00Z","timestamp":1788307200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100005224","name":"National Center for Immunization and Respiratory Diseases","doi-asserted-by":"publisher","award":["75D30120C08379"],"award-info":[{"award-number":["75D30120C08379"]}],"id":[{"id":"10.13039\/100005224","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Age is a crucial factor in COVID-19 risk and severity, however its role in humoral immunity is unclear. This study compares associations between age and immune response following COVID-19 vaccination and SARS-CoV-2 infection.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Data from the Arizona Healthcare, Emergency Response, and Other Essential Workers study (AZ-HEROES), a prospective cohort, were used to create two analytic groups: 1) a post-vaccination cohort including individuals who received two doses of the monovalent ancestral mRNA COVID-19 vaccine without prior SARS-CoV-2 infection; and 2) a post-infection cohort including unvaccinated individuals after primary infection. The analysis included data from September 2020 to April 2023. Children (&lt;18 years) and adults (18\u2009+\u2009years) were compared using linear regression, with immune response measured using log-transformed area under the curve (AUC) for receptor-binding domain (RBD) and spike protein subunit (S2). Finer age groups (&lt;12, 12\u221217, 18\u221250, 50+) were also described. Adjusted models controlled for chronic conditions, medications, days since vaccination or infection, recent exposure to SARS-CoV-2 (post-vaccination only), strain type (post-infection only), and sociodemographic variables.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The post-vaccination analysis included 749 participants, while the post-infection analysis included 203 participants. Participants were predominantly non-Hispanic White adults, with median ages of 43 and 40 years in the post-vaccination and post-infection cohorts, respectively. Most reported no chronic conditions. In adjusted post-vaccination analysis, adults had 7% higher RBD AUC (95% CI: 1.01\u20131.13) and 20% higher S2 AUC (95% CI: 1.13, 1.28) than children, although these results were attenuated when restricted to individuals taking the BNT162b2 vaccine only. Post-infection, adults had 22% higher S2 AUC (95% CI: 1.05, 1.40), while RBD differences were not significant. By finer age breakdown, adolescents (12\u221217 years) had stronger responses than children younger than 12 post-vaccination, with 26% higher RBD AUC (95% CI: 1.13\u20131.40) and 29% higher S2 AUC (95% CI: 1.14\u20131.46).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>COVID-19 immune responses differ between children and adults, with adolescents exhibiting stronger immune response to vaccination than children younger than 12, however vaccine dosage may play a role in this observed difference. Age-related differences after infection were limited to S2 antibody responses.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0356178","type":"journal-article","created":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T17:33:41Z","timestamp":1788370421000},"page":"e0356178","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Age-specific humoral immune response to SARS-CoV-2: A comparative analysis of antibody levels in children and adults after vaccination with primary series or infection"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-5767-5414","authenticated-orcid":true,"given":"Brooke A.","family":"Hawkes","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James","family":"Hollister","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9232-0279","authenticated-orcid":true,"given":"Cynthia","family":"Porter","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3631-8072","authenticated-orcid":true,"given":"Zoe L.","family":"Lyski","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2362-9509","authenticated-orcid":true,"given":"Jefferey L.","family":"Burgess","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karen","family":"Lutrick","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shawn C.","family":"Beitel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryan S.","family":"Sprissler","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7624-312X","authenticated-orcid":true,"given":"Katherine D.","family":"Ellingson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,9,2]]},"reference":[{"issue":"2","key":"pone.0356178.ref001","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1165\/rcmb.2021-0455ED","article-title":"Differences between Children and Adults with COVID-19: It\u2019s Right under Our Nose","volume":"66","author":"ED Morrell","year":"2022","journal-title":"Am J Respir Cell Mol Biol"},{"issue":"7","key":"pone.0356178.ref002","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1007\/s12098-020-03322-y","article-title":"Pathophysiology of COVID-19: Why Children Fare Better than Adults?","volume":"87","author":"N Dhochak","year":"2020","journal-title":"Indian J Pediatr"},{"issue":"5","key":"pone.0356178.ref003","doi-asserted-by":"crossref","first-page":"801","DOI":"10.3390\/v16050801","article-title":"The Effect of Age and Comorbidities: Children vs. Adults in Their Response to SARS-CoV-2 Infection","volume":"16","author":"G Mentor","year":"2024","journal-title":"Viruses"},{"key":"pone.0356178.ref004","unstructured":"CDC. 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