{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T23:27:05Z","timestamp":1788910025071,"version":"build-2803163510"},"reference-count":43,"publisher":"Wiley","issue":"10","license":[{"start":{"date-parts":[[2024,10,21]],"date-time":"2024-10-21T00:00:00Z","timestamp":1729468800000},"content-version":"vor","delay-in-days":20,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["R01AI168373\u201002"],"award-info":[{"award-number":["R01AI168373\u201002"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000030","name":"Centers for Disease Control and Prevention","doi-asserted-by":"publisher","award":["75D30120C07765"],"award-info":[{"award-number":["75D30120C07765"]}],"id":[{"id":"10.13039\/100000030","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Influenza Resp Viruses"],"published-print":{"date-parts":[[2024,10]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>The aim of this study is to determine the incidence and risk factors associated with COVID\u201019 hospitalization among unvaccinated children.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Children aged 0\u2013\u2009&lt;\u200918\u2009years, members of Kaiser Permanente Northern California (KPNC), were followed from March 1, 2020, until the earliest occurrence of: chart\u2010confirmed COVID\u201019 hospitalization, disenrollment from KPNC, age 18\u2009years, receipt of COVID\u201019 vaccine, death, or study end (December 31, 2022). We calculated the incidence rate of hospitalization by SARS\u2010CoV\u20102 variant period and by age group. We determined risk factors for hospitalization using Poisson regression. We also conducted descriptive analyses of hospitalized cases.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Among 1,107,799 children, 423 were hospitalized for COVID\u201019 during follow\u2010up. The incidence of hospitalization increased with each new SARS\u2010CoV\u20102 variant and was highest among children aged &lt; 6\u2009months. Among the &lt; 6\u2010month\u2010olds, the incidence rate per 100,000 person\u2010months was 7 during predelta, 13.3 during delta, and 22.4 during omicron. Black (RR\u2009=\u20092.05, 95% CI: 1.33\u20133.16) and Hispanic children (RR\u2009=\u20091.82, 95% CI: 1.34\u20132.46) and children with any comorbidities were at high risk of hospitalization (RR\u2009=\u20093.81, 95% CI: 2.94\u20134.95). Overall, 20.3% of hospitalized children were admitted to an intensive care unit (ICU), but ICU admission was 36.1% among 12\u2013\u2009&lt;\u200918\u2010year\u2010olds. The majority of ICU admits (91.8%) had no comorbidities.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Children too young to be vaccinated had the highest incidence of COVID\u201019 hospitalization, while adolescents had the highest proportion of ICU admissions. To prevent severe disease in children and adolescents, everyone eligible should be vaccinated.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/irv.70022","type":"journal-article","created":{"date-parts":[[2024,10,21]],"date-time":"2024-10-21T03:49:20Z","timestamp":1729482560000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Incidence and Risk of Coronavirus Disease 2019 Hospitalization Among Unvaccinated Children"],"prefix":"10.1111","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8380-6215","authenticated-orcid":false,"given":"Ousseny","family":"Zerbo","sequence":"first","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julius","family":"Timbol","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John\u00a0R.","family":"Hansen","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristin","family":"Goddard","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evan","family":"Layefsky","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pat","family":"Ross","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bruce","family":"Fireman","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dao","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Department of Pediatrics Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tara\u00a0L.","family":"Greenhow","sequence":"additional","affiliation":[{"name":"Pediatrics Infectious Diseases Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicola\u00a0P.","family":"Klein","sequence":"additional","affiliation":[{"name":"Vaccine Study Center Kaiser Permanente Northern California  Oakland California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,10,21]]},"reference":[{"key":"e_1_2_12_2_1","unstructured":"American Academy of Pediatrics and the Children's Hospital Association. \u201cChildren and COVID\u201019:State Data Report. 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