LAUSR

We would like to share ideas on the publication “Antibody response to mRNA SARS-CoV-2 vaccination in 182 patients after allogeneic hematopoietic cell transplantation.” 1 While cases undergoing allogeneic stem cell transplantation were excluded from the initial registration trials, Beerlage et al. stated that “our real-world expe-rience with a large patient cohort confirms the data of previous studies, showing that the majority of patients have a good response to mRNA-vaccines against SARS-CoV-2.” 1 Despite immunosuppressive medication, a large proportion of patients have insufficient vaccination, which can be improved in most cases after a third vaccine. 1 We agree that the immune response to COVID-19 vaccine among patients after allogeneic hematopoietic cell transplantation might be different from general healthy population. The current study by Beerlage et al. might showed that a level of immune response is detected after vaccination. The important concern is on the confounding effect of the asymptomatic COVID-19. 2 The asymptomatic COVID-19 is a common problem and there is no specific protocol to rule out prevac-cination and postvaccination asymptomatic COVID-19 among study transplant recipients. Whether the observed immune parameter is a result of confounding asymptomatic COVID-19 is an interesting question. authors interest.