Seven-Valent Pneumococcal Conjugate Vaccine in Pediatric Solid Organ Transplant Recipients A Prospective Study of Safety and Immunogenicity

Objectives: To determine the safety and immunogenicity of the conjugate pneumococcal vaccine (PCV7) in pediatric solid organ transplant recipients. Patients and Methods: Pediatric solid organ transplant recipients were prospectively enrolled at >= 4 months following transplantation. Eligible pneumococcal vaccine-naive subjects received 3 doses of PCV7 at 8 week intervals, followed 8 weeks later by a dose of the 23-valent vaccine (PV23). Serology was done at baseline, 8 weeks following doses 2 and 3 of PCV7 and 8-12 weeks after PV23. Repeated measures analyses were done using SAS 9. Results: Eighty-one recipient, commenced immunization at a median age of 7.8 (0.6-17.5) years and a median time from transplantation to immunization of 1.3 (0.3-6.0) years. There were 31 heart, 18 liver, 5 lung, and 27 kidney recipients. Reported adverse events following vaccine doses included local reactions (PCV7: PV23 = 19%:16%) and fever (PCV7: PV23 = 3.8%;4.9%) and there were no serious reactions. Two doses of PCV7 induced >= 2 fold increases in geometric mean concentrations (GMCs) in all organ groups. Cardiac and lung recipients demonstrated additional benefit from a third dose of PCV7. The cardiac recipients showed most benefit from boosting with PV23 with significant increases in GMC's (P <= 0.008). The time of initiation of the vaccine strategy posttransplantation predicted seroprotection. Conclusion: PCV7 was safe and immunogenic in solid organ recipients. Three doses of this vaccine appear beneficial for selected organ groups. PV23 when administered at >= 1 year posttransplantation was useful in boosting antibody responses in patient groups demonstrating lower rates of responsiveness.