Moreno-Nunez, PalomaBueno-Cavanillas, AuroraSan Jose-Saras, DiegoVicente-Guijarro, JorgeFernandez Chavez, Abelardo ClaudioAranaz-Andres, Jesus Maria2023-05-032023-05-032022-07-052077-0383http://hdl.handle.net/10668/21317(1) Background: The development of effective COVID-19 vaccines has reduced the impact of COVID-19 on the general population. Our study aims to analyze how vaccination modifies the likelihood of death and length of stay in hospitalized patients with COVID-19; (2) Methods: A retrospective cohort study of 1927 hospitalized patients infected with COVID-19 was conducted. Information was gathered on vaccination status, hospitalization episode, and clinical profile of the patients. The effect of vaccination on mortality was analyzed using a multiple logistic regression model, and length of stay was analyzed using linear regression. The performance and fit of the models were evaluated; (3) Results: In hospitalized patients with COVID-19, the risk of dying during admission in vaccinated patients was half that of non-vaccinated (OR: 0.45; CI 95%: 0.25 to 0.84). In patients who were discharged due to improvement, the reduction in hospital stay in vaccinated patients was 3.17 days (CI 95%: 5.88 to 0.47); (4) Conclusions: Patients who, despite having been vaccinated, acquire the infection by SARS-CoV-2, have a significant reduction of the risk of death during admission and a reduction of hospital stay compared with unvaccinated patients.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/COVID-19 vaccinescritical carehospital mortalityhospitalisationvaccine effectivenessHumansLength of StayPatient DischargeCOVID-19 VaccinesSARS-CoV-2Logistic ModelsLinear ModelsRetrospective StudiesCOVID-19HospitalizationVaccinationresearch article35807189open accessModelos linealesModelos logísticosSARS-CoV-2Tiempo de internaciónVacunaciónVacunas contra la COVID-19Hospitalización10.3390/jcm11133905PMC9267443https://www.mdpi.com/2077-0383/11/13/3905/pdf?version=1656992809https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9267443/pdf