Immunogenicity of the meningococcal polysaccharide conjugate vaccine in pediatric kidney transplant patients.

BACKGROUND: Immunosuppressed kidney transplant patients may have suboptimal response to vaccinations. The aim of this study was to determine antibody response to a quadrivalent meningococcal conjugate vaccine (MenACWY-D) in adolescents with a kidney transplant.

METHODS: This was a prospective, single-center, cohort study. Adolescent patients (11-22 years old) with a functioning kidney transplant for at least 3 months and no previous meningococcal vaccination were eligible for enrollment. Antibody levels to all serogroups were measured before vaccination (baseline) and at 4 weeks and 1, 2 and 3 years after vaccination. Seropositivity was defined as a titer ≥ 1:8 at baseline, and seroconversion as a fourfold or greater increase in antibody titer from baseline at 4 weeks post-vaccination. Geometric mean titers (GMTs) were calculated at each time point and compared to published GMTs from vaccinated healthy adolescents.

RESULTS: Nineteen patients were enrolled. No patient had seroprotective titers against all four serogroups at baseline. At 4 weeks post-vaccination 41% of patients seroconverted to all four serogroups, with seroconversion rates of 88, 53, 71 and 94% for serogroups A, C, W and Y, respectively. GMTs were significantly lower in adolescents with a kidney transplant than in healthy adolescents at 1 month (p = 0.02) and 3 years (p = 0.04) post-vaccination. There were no significant adverse events, episodes of rejection or death in any patient.

CONCLUSIONS: Adolescents with a kidney transplant may not respond adequately to MenACWY-D and may experience more rapid declines in antibody titers than healthy adolescents. Further study is needed to determine if alternative dosing schedules can improve antibody response in this population.