Patients undergoing hematopoietic
cell transplantation (HCT) are at increased risk for
infections with Streptococcus pneumoniae and have long-lasting, impaired antibody responses to pneumococcal
polysaccharide vaccines. We examined whether donor immunization with a
heptavalent pneumococcal conjugate vaccine (PCV7) would elicit protective antibody responses to additional doses of
vaccine administered early after
transplantation. Ninety-six patients scheduled to receive an allogeneic hematopoietic cell transplant were randomized with their donors to receive either a dose of
PCV7 vaccine or no
vaccine before
transplantation. All patients received PCV7 at 3 months, 6 months, and 12 months following
transplantation, and serotype-specific antibody concentrations were determined after each dose. Following HCT, geometric mean antibody concentrations of patients in the immunized donor group were significantly higher for 5 of the 7
vaccine serotypes after one dose (P <.05) and for 4 of the 7 serotypes after 2 doses of
vaccine (P <.03). Sixty-seven percent of patients in the immunized donor group had presumed protective
IgG concentrations more than or equal to 0.50 microg/mL to all 7 serotypes following the first dose of
vaccine compared to 36% in the unimmunized donor group (P =.05). After the third dose of
vaccine, both groups had more than 60% of patients with concentrations at least 0.50 microg/mL to all
vaccine serotypes. Donor immunization enhances early antibody responses of patients undergoing HCT to pneumococcal
conjugate vaccine. A 3-dose schedule of
PCV7 vaccine at 3, 6, and 12 months is immunogenic in these patients regardless of donor immunization.