440 - Long-Term Live Attenuated Vaccine Immunity in Pediatric Liver Transplant Patients

Sunday, April 30, 2023

3:30 PM – 6:00 PM ET

Japan Pediatric Society Fellow Exchange Award

Poster Number: 440
Publication Number: 440.323

Takuma Ohnishi, Keio University School of Medicine, Shinjuku, Tokyo, Japan; Mizuki Yaginuma, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Munehiro Furuichi, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Yohei Yamada, Keio University School of Medicine, Shinjuku, Tokyo, Japan; Ken Hoshino, KEIO University School of Medicine, Shinjuku-ku, Tokyo, Japan; Tetsuo Nakayama, Kitasato University, Tokyo, Tokyo, Japan; Takao Takahashi, Dept of Pediatrics, Keio Univ School of Medicine, Shinjuku-ku, Tokyo, Japan; Masayoshi Shinjoh, Keio University, Tokyo, Tokyo, Japan

Presenting Author(s)

Takuma Ohnishi, Medical Doctor and Doctor of Philosophy (he/him/his)

Assistant teacher
Keio University School of Medicine
Shinjuku, Tokyo, Japan

Background:

Administration of live attenuated vaccines, including measles, rubella, varicella zoster virus (VZV) and mumps vaccines, after living donor liver transplantation (LDLT) is controversial because of its theoretical risks. Although several reports have described the safety and effectiveness of vaccination of pediatric LDLT recipients, limited data are available on the long-term outcomes of vaccination.

Objective: This study aimed to assess the seroconversion rates and the duration of vaccine-induced immunity in pediatric LDLT recipients.

Design/Methods: Since 2002, subcutaneous immunizations with live-attenuated vaccines against VZV, mumps, rubella, and measles in pediatric patients has been performed following LDLT in those who fulfilled clinical criteria, including humoral and cell-mediated immunity. We investigated the response to each vaccine 1–3 months after the first immunization and every 6 months thereafter. Patients with positive antibody titers after the first post-transplant vaccination were followed-up until April 2022 to assess the duration of positive antibody titers.

Results:

A total of 208 immunizations were administered to 66 pediatric post-LDLT recipients. The seroconversion rates after the first dose of measles (AIK-C), measles (Tanabe), rubella (TO-336), rubella (Matsuura), varicella (Oka), mumps (Torii), and mumps (Hoshino) were 100% (38/38), 81.3% (13/16), 97.8% (44/45), 72.7% (8/11), 63% (29/46), 0% (0/3), and 71.4% (35/49), respectively. The median durations of positive antibody titers were 79 months for measles (AIK-C), 12 months for measles (Tanabe), 13 months for rubella (Matsuura), and 14 months for varicella (Oka). The antibody titers for rubella (TO-336) and mumps (Hoshino) remained positive in 98% and 78% of the patients, respectively. Among Measles, Rubella and Mumps vaccines, there are significant difference on seroconversion rates and duration of positive antibody titers between vaccine strains No patient developed vaccine-associated serious adverse events.

Conclusion(s):

In children who were not severely immunosuppressed after LDLT, the seroconversion rates and duration of positive antibody titers vary greatly among vaccine strains. Repeated immunizations with all strains except rubella (TO-336) and mumps (Hoshino) are recommended.