S. Haggenburg MD, Q. Hofsink MD, A.E.C. Broers MD, PhD, J.A. van Doesum MD, C. van Elssen MD, PhD, R.S. van Binnendijk PhD, G. den Hartog PhD, J. Heijmans MD, PhD, P.G.N.J. Mutsaers MD, PhD, T. van Meerten MD, PhD, C.J.M. Halkes MD, PhD, M.H.M. Heemskerk MD, PhD, A. Goorhuis MD, PhD, C.E. Rutten MD, PhD, M.D. Hazenberg MD, PhD, I.S. Nijhof MD, PhD
Patients with haematologic diseases are at high risk for severe coronavirus disease 2019 (COVID-19) and COVID-19-related death. In early 2021, haematology patients were therefore prioritized for SARS-CoV-2 vaccination by the Dutch government. It was however not known whether they would be able to generate a protective immune response to SARS-CoV-2 vaccines, given the immunodeficiencies that often accompany hematologic conditions and the therapy thereof. National and international cohort studies demonstrated an adequate antibody response after a standard 2-dose mRNA vaccination schedule in a larger number of patients than expected. After the third dose, the majority of immunocompromised haematology patients obtained SARS-CoV-2 antibody concentrations similar to the antibody concentrations obtained by healthy individuals after the standard 2-dose mRNA-1273 schedule. The primary COVID-19 vaccination schedule for haematology patients should therefore consist of three instead of two mRNA vaccinations. B cell depleted patients and patients who received allogeneic hematopoietic progenitor cell transplantation (HCT) should be revaccinated. The number and the exact timing of revaccinations remains to be determined however. In conclusion, SARS-CoV-2 vaccination should not be postponed in patients on or shortly after therapy for hematologic conditions.