Harrison et al.
Humoral immune response to tick-borne encephalitis vaccination in allogeneic blood and marrow graft recipients.
npj Vaccines, 2020;5:67. doi:10.1038/s41541-020-00215-1
Allogenic hematopoietic stem cell transplant (HSCT) and marrow graft recipients have an increased risk for infections due to delayed immune reconstitution, immunosuppressive therapy, and graft-versus-host disease. Therefore, various vaccinations are recommended for these patients, including vaccination for TBE for patients living in endemic areas, although no data on effectiveness in HSCT patients exist. A single-center study has been carried out to characterize the immune response to TBE vaccination one year after transplantation compared to healthy controls.
One year after HSCT, the majority of patients (79%) still had neutralizing antibodies. However, a strong decline of NT titer before HSCT to one year after HSCT has been observed and all patients were boosted. HSCT patients had a reduced immune response to TBE vaccination, as only 35% of patients, but 93% of controls, exhibited an at least twofold increase of the NT four weeks after the second vaccination. Only patients without previous vaccination did not respond after the second TBE vaccination but received a protective antibody response after the third vaccination. Following vaccination, antibody response in HSCT patients was associated with CD+ cell count. NT test remains the gold standard for assessment of TBE specific humoral immunity in HSCT patients.