Nationwide longitudinal analysis of COVID-19 hospitalisation burden in immunocompromised patients

The COVID-19 pandemic has caused over 7 million deaths worldwide, with age, underlying conditions, and immunosuppression increasing the incidence of severe outcomes. Despite vaccination, immunocompromised (IC) individuals show lower vaccine response, probably leading to more breakthrough infections. The objective of our study was to evaluate the overall occurrence of intensive care admission and/or death during hospitalisation, stratified by COVID-19 severity and immunological status (IC vs. non-IC individuals). Our study used a nationwide database to compare COVID-19 hospitalisations and outcomes in IC versus non-immunocompromised individuals (non-IC). This is a longitudinal cohort study analysed de-identified COVID-19 data from Brazil's DATASUS system (02 March 2020-31 December 2023). The study included 361,898 subjects, identifying 7484 (2.07%) IC individuals. IC individuals showed higher rates of chronic liver, neurological, and lung diseases, while non-IC individuals had higher obesity rates. Intensive care unit (ICU) admissions (42.6% vs. 38.5%) and mortality (51.1% vs. 35.9%) were greater in IC compared to non-IC individuals. Therefore, IC individuals consistently experienced more ICU admissions and higher mortality across the COVID-19 pandemic years (odds ratios rising from 1.68 in 2020 to 2.39 in 2023), influenced by the prevalence of SARS-Cov-2 variants. Our study shows higher morbidity and mortality in IC individuals during the COVID-19 pandemic, underscoring the need for targeted strategies like early interventions, reinforcing the need for sustained surveillance, targeted vaccination strategies, and prioritised care.