Severe acute respiratory syndrome coronavirus 2 infection in patients with hematological malignancies in the Omicron era: Respiratory failure, need for mechanical ventilation and mortality in seronegative and seropositive patients.

: HM patients with negative SARS-CoV2 serology, despite vaccinations and previous infections, have worse clinical outcomes compared to seropositive patients in the Omicron era. The use of serology for SARS-CoV2 diagnosis could be an easy tool to identify patients prone to developing complications.