There have been no recommendations for revaccination with the Japanese encephalitis (JE) vaccine in post-hematopoietic stem cell transplantation (HSCT) patients. This study aimed to measure the immunogenic response to a live-attenuated JE vaccine (SA 14-14-2) in post-HSCT patients. JE-specific neutralizing Ab titers were measured before and after the JE vaccination. The patients with Ab titers o 10 at the 3-month time point received a second injection at 6 months. A total of 28 patients (male:female = 11:17) with a median age of 13 years (4-21 years) were included. The underlying diseases were thalassemia (50%) and hematologic malignancies (50%). Ten patients (35.7%) had Ab titers above the preventive level before vaccination. Nine of 18 patients (50%) seroconverted at 3 months after a single JE vaccination, but only three of these patients had sustained protective Ab levels. Seven of nine patients (78%) seroconverted at 3 months after a second JE vaccine injection, and all of these patients sustained protective Ab levels at 12 months. In conclusion, post-HSCT patients had low seroconversion rates after a single dose of the live-attenuated JE vaccine. These patients may require at least two doses of the JE vaccine to ensure protective Ab levels.

actively treated for graft-versus-host disease (GVHD). The median (range) ANC and ALC at the time of RSV diagnosis was 1.6 (0 -11) and 0.8 (0 -7.3), respectively. Among the 35 patients with URTI, 12 received IR while 23 did not. None of the 12 patients treated with IR progressed to LRTI. In contrast, 6 of the 23 untreated patients (24%) with URTI progressed to LRTI. Of the 31 patients with LRTI (25 initially diagnosed with LRTI and 6 patients who progressed from URTI to LRTI), there were four deaths occurring within 60 days of RSV diagnosis (two deaths directly from RSV, one from disease relapse, and one from GVHD). In patients with LRTI (25 patients with LRTI at diagnosis plus 6 patients who progressed from URTI to LRTI), RSV-related mortality was (6.4%). On univariate analysis, only the presence of GVHD significantly predicted the development of LRTI in patients with URTI (P ¼ .028); however, the use of inhaled ribavirin had a protective effect that was marginally significant (P¼ .074). Early use of IR in high-risk transplant and leukemia patients can both reduce the progression from URTI to LRTI and improve the historically dismal outcomes of patients with RSV pneumonia.Abstracts / Biol Blood Marrow Transplant 20 (2014) S184eS210 S198