573. High Rate of Vaccine Failure after Administration of Acellular Pertussis Vaccine Pre- and Post-Liver Transplantation in Children
Session: Oral Abstract Session: Immunization of Children and Adults with Immune Deficiencies
Thursday, October 3, 2013: 2:45 PM
Room: The Moscone Center: 250-262
Background: Efficacy of acellular pertussis vaccine for solid organ transplantation recipients has not been reported in literature. We aimed to evaluate the factors that influence the efficacy of pertussis vaccines given pre- and post- liver transplantation (LT).

Methods: Patients were enrolled after informed consent before and after LT then followed prospectively. Diphteria, tetanus and acellular pertussis (DTaP) vaccine containing two pertussis antigens; pertussis toxin (PT) and filamentous hemagglutinin (FHA) were administered at least 2 weeks prior to LT and ≥ 1 year after LT if patients’ liver function was stable. We collected information on patients who completed the current Japanese standard of four total doses of DTaP. Serum antibody titers for pertussis (PT and FHA) were investigated and were considered positive when titers were ³a10 EU/ml . 

Results: Serological analyses for pertussis were performed on 54 patients and were positive in 44.4% for PT antibody and 70.4% for FHA antibody. Patients who received all four doses of the vaccine after transplantation were more likely to be seropositive compared to those who received part of their vaccination prior to transplant [5/6 (83.3%) vs. 19/48 (39.6%): p=0.07] although the small numbers precluded definitive conclusions. Multivariate analysis revealed that earlier age at the time of 1st, 2nd and 4th DTaP administration (1st: 5 vs. 9 months, 2nd: 7 vs. 12 months, 3rd: 9 vs. 15 months, 4th: 28 vs. 33 months; P=0.001, 0.02, 0.35, 0.02), earlier age and body weight at the time of testing (age; 49 vs. 98 months, weight: 16 vs. 21.9kg;P= 0.03, 0.005), were risk factors for seronegative status for PT antibody. Other demographic factors, clinical parameters and laboratory values analyzed did not differ significantly.

Conclusion: The combined four dose regimen for DTaP pre- and post- LT was insufficient to achieve seropositive status in over half of the patients post LT. Booster or re-immunization should be considered for patients after LT especially for those who received their vaccines at an earlier age.

Kenta Ito, MD1, Takanori Funaki, MD1, Kensuke Shoji, MD1, Ippei Miyata, MD, PhD1, Seisuke Sakamoto, MD, PhD1, Mureo Kasahara, MD1, Akihiko Saitoh, MD, PhD1,2 and Isao Miyairi, MD1, (1)National Center for Child Health and Development, Tokyo, Japan, (2)Pediatrics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan

Disclosures:

K. Ito, None

T. Funaki, None

K. Shoji, None

I. Miyata, None

S. Sakamoto, None

M. Kasahara, None

A. Saitoh, None

I. Miyairi, None

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