{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T13:02:01Z","timestamp":1789650121693,"version":"4.0.0"},"reference-count":32,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T00:00:00Z","timestamp":1789344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: Influenza vaccination is widely recommended to prevent influenza and its complications; however, its association with clinical outcomes among high-risk populations remains uncertain. This study aimed to investigate the association between influenza vaccination status and clinical outcomes among adults hospitalized with community-acquired pneumonia (CAP) in Saudi Arabia. Methods: This retrospective cohort study included adults hospitalized with CAP in Saudi public hospitals between October 2023 and March 2024. Data on demographic characteristics, comorbidities, influenza vaccination status, laboratory-confirmed influenza infection, intensive care unit (ICU) admission, in-hospital mortality, and length of hospital stay were obtained from electronic health records. Logistic regression analyses were performed to evaluate the associations between influenza vaccination and clinical outcomes. Results: Among 485 patients, 114 (23.5%) had received the seasonal influenza vaccine. The prevalence of laboratory-confirmed influenza infection was similar among vaccinated and unvaccinated patients (57.9% vs. 58.5%, p-value = 0.910). Vaccinated patients were less likely to require ICU admission (1.8% vs. 7.5%, p-value = 0.025), while no significant differences were observed in length of hospital stay or in-hospital mortality. After adjustment for age, sex, and comorbidities, influenza vaccination was associated with lower odds of ICU admission (OR = 0.200, 95% CI: 0.045, 0.894). No significant associations were observed between influenza vaccination and laboratory-confirmed influenza infection, length of hospital stay, or in-hospital mortality. Conclusions: Among adults hospitalized with CAP in Saudi Arabia, influenza vaccination was associated with a lower likelihood of ICU admission, supporting its potential role in reducing disease severity among high-risk populations.<\/jats:p>","DOI":"10.3390\/vaccines14090810","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T14:15:04Z","timestamp":1789395304000},"page":"810","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Influenza Vaccination Status and Clinical Outcomes Among Adults Hospitalized with Community-Acquired Pneumonia: A Retrospective Cohort from Saudi Arabia"],"prefix":"10.3390","volume":"14","author":[{"given":"Shouq M.","family":"Alzaaqi","sequence":"first","affiliation":[{"name":"King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11481, Saudi 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Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Majed A.","family":"Almoghrabi","sequence":"additional","affiliation":[{"name":"Department of Otorhinolaryngology, Imam Abdulrahman Alfaisal Hospital, Ministry of Health, Riyadh 14723, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Seham F.","family":"Basheer","sequence":"additional","affiliation":[{"name":"Population Health Deputyship, Ministry of Health, Riyadh 11176, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Sami","family":"Alsaedi","sequence":"additional","affiliation":[{"name":"Global Health Directorate, Public Health Authority, Riyadh 13351, Saudi 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A.","family":"Barzanji","sequence":"additional","affiliation":[{"name":"Department of Endodontics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah 9515, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-2414-9882","authenticated-orcid":false,"given":"Samah A.","family":"Bukhari","sequence":"additional","affiliation":[{"name":"Department of Endodontics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah 9515, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-0360-6102","authenticated-orcid":false,"given":"Abeer S.","family":"Alasmari","sequence":"additional","affiliation":[{"name":"Department of Periodontics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah 9515, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-7900-8307","authenticated-orcid":false,"given":"Abdullah M.","family":"Alyemeny","sequence":"additional","affiliation":[{"name":"Department of Respiratory Services, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Abdulaziz A.","family":"Alshaalan","sequence":"additional","affiliation":[{"name":"Department of Respiratory Services, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi 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Antibiotics, 14.","DOI":"10.3390\/antibiotics14070642"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/9\/810\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T12:04:38Z","timestamp":1789646678000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/9\/810"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,14]]},"references-count":32,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["vaccines14090810"],"URL":"https:\/\/doi.org\/10.3390\/vaccines14090810","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,14]]}}}