Clinical Impact of Sars-Cov-2 Vaccination in COVID-19 Outcomes in Patients Diagnosed with Hematologic Malignancies: Real-World Evidence of Two Years of Pandemic

Background: Real-world data about the effectiveness of SARS-CoV-2 vaccination and implementation of booster campaigns in an immunocompromised population such as patients diagnosed with hematologic malignancies (HM) are scarce. Our aim was to compare morbidity and mortality of COVID-19 according to SARS-CoV-2 vaccination status and immuno-logical response to vaccination in a cohort of patients diagnosed with HM, considering a scenario affected by the succession of diverse virus variants and the advent of COVID-19 speci fi c therapies. Methods: We retrospectively collected clinical data from the patients with a current or prior history of HM at Vall d ’ Hebron Universitary Hospital who suffered a laboratory-con fi rmed SARS-CoV-2 infection between March 2020 and May 2022. The main endpoints included severity of COVID-19 (WHO classi fi cation), rate of hospitalization, ICU admission, need for supplemental oxygen or COVID-19 speci fi c therapy (steroids, antivirals, IL-6 inhibitors, hydroxychloroquine, anti-SARS-CoV-2 monoclonal antibodies). We also genotyped viral variants and assessed humoral immunogenicity induced by the vaccine (anti-spike[S] 05/22,