Effect of donor immunization on antibody responses to heptavalent pneumococcal conjugate vaccine (PCV7) following HCT.

Geometric mean IgG antibody concentrations to the 7 vaccine serotypes of patients whose donors were immunized with PCV7 compared to those patients whose donors were not immunized before transplantation. As indicated by the arrowheads, all patients received PCV7 at 3 months, 6 months, and 12 months after HCT. Geometric mean antibody concentrations marked with asterisks (*) were significantly higher for the immunized donor group compared to the unimmunized donor group for all vaccine serotypes (P ≤ .05) except for serotype 4.