Post-Acute Sequelae of COVID-19 at 12 Months in Hospitalized Patients: A Colombian Cohort Study

Background/objectives: Post-acute sequelae of SARS-CoV-2 infection (PASC) are a major source of long-term morbidity among COVID-19 survivors, particularly after hospitalization. However, information on PASC prevalence and associated factors at 12 months in Latin America remains limited. This study aimed to estimate the prevalence of PASC at 12 months among hospitalized COVID-19 patients and to identify factors associated with its persistence. Methods: We conducted an ambidirectional, single-center cohort study including adult patients hospitalized with laboratory-confirmed SARS-CoV-2 infection who completed follow-up evaluations at six and 12 months after discharge. PASC was defined according to the World Health Organization (WHO) criteria. Sociodemographic variables, comorbidities, markers of in-hospital disease severity, and follow-up information were collected using standardized protocols. Statistical analyses included descriptive and bivariate comparisons according to PASC status at 12 months. Results: Among 869 hospitalized COVID-19 survivors, the prevalence of PASC at 12 months was 40.7% (n=354). Female sex, markers of severe acute disease, and the presence of PASC at six months were significantly associated with PASC persistence at 12 months. Vaccination coverage at follow-up was high, and although adverse reactions to vaccination were more frequently reported among patients with PASC, no differences in PASC development were observed according to vaccine platform. Conclusions: More than two out of five patients experienced PASC one year after hospitalization for COVID-19. Associations with severe acute disease and vaccine reactogenicity support the hypothesis that dysregulated host immune responses may contribute to persistent post-COVID symptoms, highlighting the need for early identification and longitudinal follow-up of high-risk patients.