{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T02:38:47Z","timestamp":1790735927876,"version":"4.1.0"},"reference-count":41,"publisher":"American Medical Association (AMA)","issue":"8","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA Intern Med"],"published-print":{"date-parts":[[2026,8,1]]},"abstract":"<jats:sec id=\"ab-ioi260031-4\">\n                    <jats:title>Importance<\/jats:title>\n                    <jats:p>Vaccine effectiveness (VE) estimates are needed to monitor the effect of updated COVID-19 vaccinations.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"ab-ioi260031-5\">\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To assess the effectiveness of 2024-2025 COVID-19 vaccines against medically attended COVID-19 among adults 18 years and older in the US.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"ab-ioi260031-6\">\n                    <jats:title>Design, Setting, and Participants<\/jats:title>\n                    <jats:p>This case-control study with a test-negative design included patient encounters with a COVID-19\u2013like illness discharge diagnosis code and a molecular or antigen SARS-CoV-2 test within 10 days before to 3 days after the encounter date, from September 5, 2024, to September 2, 2025. Encounters were captured in VISION (Virtual SARS-CoV-2, Influenza, and Other Respiratory Viruses Network), a multisite, electronic medical record\u2013based network of health care systems, including 381 emergency department\/urgent care (ED\/UC) departments and 246 hospitals in 6 states.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"ab-ioi260031-7\">\n                    <jats:title>Exposure<\/jats:title>\n                    <jats:p>Vaccination with a 2024-2025 COVID-19 vaccine formulation (approved by the US Food and Drug Administration in August 2024) in the previous 7 to 299 days.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"ab-ioi260031-8\">\n                    <jats:title>Main Outcomes and Measures<\/jats:title>\n                    <jats:p>Outcomes were COVID-19\u2013associated ED\/UC encounters, COVID-19\u2013associated hospitalization, and COVID-19\u2013associated critical illness (hospitalization with an intensive care unit admission or in-hospital death). Encounters with a positive molecular or antigen SARS-CoV-2 test result were classified as cases, and encounters with a negative molecular SARS-CoV-2 test result were classified as controls. The odds of 2024-2025 COVID-19 vaccination were compared among cases and controls, adjusting for confounders, with estimated VE calculated as (1\u2009\u2212\u2009adjusted odds ratio)\u2009\u00d7\u2009100%.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"ab-ioi260031-9\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>In 333\u202f262 eligible ED\/UC encounters (median [IQR] age of patients, 54 [35-72] years; 60% female) and 97\u202f663 eligible hospitalizations among immunocompetent adults 18 years and older (median [IQR] age of patients, 72 [59-81] years; 53% female), estimated VE was 26% (95% CI, 23%-29%) against COVID-19\u2013associated ED\/UC encounters, 35% (95% CI, 30%-40%) against COVID-19\u2013associated hospitalization, and 41% (95% CI, 28%-51%) against COVID-19\u2013associated critical illness 7 to 299 days after vaccination. Among immunocompetent adults 65 years and older (122\u202f663 ED\/UC encounters and 63\u202f958 hospitalizations), estimated VE was 26% (95% CI, 22%-30%) against COVID-19\u2013associated ED\/UC encounters, 35% (95% CI, 29%-40%) against COVID-19\u2013associated hospitalization, and 41% (95% CI, 28%-52%) against COVID-19\u2013associated critical illness 7 to 299 days after vaccination. Among 32\u202f629 hospitalizations in immunocompromised adults 18 years and older, estimated VE against COVID-19\u2013associated hospitalization was 24% (95% CI, 13%-34%). VE estimates waned with more time since vaccination.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"ab-ioi260031-10\">\n                    <jats:title>Conclusions and Relevance<\/jats:title>\n                    <jats:p>In this test-negative case-control study, 2024-2025 COVID-19 vaccination was associated with reduced likelihood of medically attended COVID-19\u2013associated outcomes among immunocompetent and immunocompromised adults, highlighting the importance of adults receiving recommended COVID-19 vaccinations.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1001\/jamainternmed.2026.1936","type":"journal-article","created":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T15:30:38Z","timestamp":1781537438000},"page":"976","source":"Crossref","is-referenced-by-count":5,"title":["Estimated Effectiveness of 2024-2025 COVID-19 Vaccines in Adults"],"prefix":"10.1001","volume":"186","author":[{"given":"Ryan E.","family":"Wiegand","sequence":"first","affiliation":[{"name":"National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amanda B.","family":"Payne","sequence":"additional","affiliation":[{"name":"National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Josephine","family":"Mak","sequence":"additional","affiliation":[{"name":"National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sean","family":"Chickery","sequence":"additional","affiliation":[{"name":"Westat, Bethesda, Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah E.","family":"Reese","sequence":"additional","affiliation":[{"name":"Westat, Bethesda, Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicola P.","family":"Klein","sequence":"additional","affiliation":[{"name":"Kaiser Permanente Vaccine Study Center, Kaiser Permanente Northern California Division of Research, Oakland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaun J.","family":"Grannis","sequence":"additional","affiliation":[{"name":"Center for Biomedical Informatics, Regenstrief Institute, Indianapolis, Indiana"},{"name":"Department of Family Medicine, School of Medicine, Indiana University, Indianapolis"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toan C.","family":"Ong","sequence":"additional","affiliation":[{"name":"School of Medicine, University of Colorado Anschutz Medical Campus, Aurora"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elizabeth A. 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