Safety and immunogenicity of the tetravalent protein-conjugated meningococcal vaccine (MCV4) in recipients of related and unrelated allogeneic hematopoietic stem cell transplantation.

Given the high morbidity and mortality associated with meningococcal disease, in 2007 the Advisory Committee of Immunization Practices recommended immunization of all children ages 11-18 with a protein-conjugated meningococcal vaccine. There are limited data on the immunogenicity of this vaccine after allogeneic hematopoietic stem cell transplantation (allo-HCT). Since 2007, we have immunized 48 patients with the MCV4 vaccine. Two vaccinated patients who lacked follow-up titers were excluded from this analysis. Stem cells were derived from an HLA-identical sibling (n = 17) or an alternative donor (n = 29). The median time to vaccination was 2.34 years after allo-HCT. Only 7 patients responded to all 4 serogroups, and 16 patients responded to none of the serogroups. The response to serogroups A, C, Y, and W-135 was 52%, 30%, 46%, and 33%, respectively. The ability to respond to 2 or more serogroups was not affected by age, diagnosis, time to vaccination, or history of graft-versus-host disease. Receipt of a T cell-depleted graft was associated with a poorer response (P = .044). Eight of 16 patients who received a second MCV4 vaccination responded to all 4 serogroups. This retrospective study suggests that response to a single MCV4 vaccination is poor after allo-HCT. Administration of a 2-dose series, as currently recommended for patients with asplenia, complement deficiency, and HIV infection, should be evaluated in this patient population.