Vaccination is an important tool in the fight against the COVID-19 pandemic in patients with haematologic malignancies. The paper provides an analysis of the course of breakthrough SARS-CoV-2 infection in a group of vaccinated patients with haematological malignancy and a comparison with a historical cohort of 96 non-vaccinated patients with haematologic malignancies and bone marrow failure syndromes (two patients) in the treatment of COVID-19. A severe or critical course of COVID-19 was significantly less frequent in the group of vaccinated patients (10.2% vs. 31.4%, p = 0.003). The need for hospitalisation due to COVID-19 was significantly lower in vaccinated patients (27.1% vs. 72.6%, p < 0.0001) and the duration of hospitalisation was significantly shorter (10 vs. 14 days, p = 0.045). Vaccinated patients were insignificantly less likely to require oxygen therapy during infection. COVID-19 mortality was significantly higher in non-vaccinated patients (15.6% vs. 5.1%, p = 0.047). The paper demonstrated a significant positive effect of vaccination against COVID-19 on a less severe clinical course of infection, lower need for hospitalisation and mortality. However, the results need to be evaluated even in the context of new antivirals and monoclonal antibodies against SARS-CoV-2 or virus mutations with different biological behaviour.

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy, and 5%–20% of newly diagnosed patients present with hyperleukocytosis (HL). HL, most often defined as WBC > 100 000/μL, is a hematologic emergency associated with severe complications, early mortality, and poor prognosis, requiring immediate intervention. From November 2005 to September 2025, 65 newly diagnosed AML patients with HL underwent leukocytapheresis (LCP) at University Hospital Olomouc. Clinical data were retrospectively collected from medical records. The primary objective was to evaluate the procedural efficacy and safety. Clinical and laboratory data were analyzed. Survival outcomes were assessed by Kaplan–Meier analysis and compared using the log‐rank test. Median age at diagnosis was 57 years. Dyspnea (60.0%), neuropsychiatric symptoms (31.7%), and visual impairment (6.2%) were the most common leukostasis manifestations. LCP effectively reduced WBC counts without significant adverse events, median of 2.2 TBV was treated, and 52.3% of the patients requiring more than one session. FLT3 ‐ITD and NPM1 mutations were detected in 26/46 (56.5%) and 17/43 (39.5%), respectively, KMT2A rearrangements were present in 5/57 (8.8%). Intensive chemotherapy was feasible in 56.9% of patients, with 26.2% undergoing allo‐HSCT. Median OS was 5.9 months (95% CI: 1.3–8.4), significantly longer in therapy‐eligible patients, but outcomes remained poor, highlighting HL as an unmet clinical need. LCP remains a valuable therapeutic option for patients with HL in newly diagnosed AML. Our long‐term experience supports its safety and efficacy, particularly in symptomatic patients, as a bridge to definitive therapy regardless of treatment intensity eligibility.