Is a third SARS-CoV-2 vaccine dose efficient in allogeneic haematopoietic cell transplant recipients?

When and how often should allogeneic haematopoietic cell transplantation recipients be vaccinated against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is unclear. The report by Bankova et al. suggests that a third SARS-CoV-2 vaccine dose is important but still insufficient in some patients to establish an adequate humoral response. Commentary on: Bankova et al. Antibody response to a third SARS-CoV-2 vaccine dose in recipients of an allogeneic hematopoietic cell transplantation. Br J Haematol. 2022 (Online ahead of print). doi: 10.1111/bjh.18562. xxx.