Table 1. Characteristics of All Participants (n = 281).
| Characteristic | No. (%) |
|---|---|
| Posttransplant vaccine received | |
| MMR only | 64 (23) |
| VZV only | 45 (16) |
| MMR and VZV | 172 (61) |
| Organ type | |
| Liver | 270 (96) |
| Kidney | 9 (3) |
| Liver and kidney | 2 (1) |
| Age at transplant, median (IQR), y | 0.9 (0.6-1.7) |
| Age at first posttransplant vaccine, median (IQR), y | 8.9 (4.7-13.8) |
| Time between transplant and enrollment, median (IQR), y | 6.3 (3.4-11.1) |
| History of at least 1 dose of pretransplant vaccine | |
| MMR | 102 (36) |
| VZV | 95 (34) |
| History of preenrollment use of thymoglobulin, rituximab, or alemtuzumab biologic | 15 (5) |
| History of receiving blood products within the year of enrollment | 11 (4) |
| History of any rejection in the 2 y before enrollment | 35 (12) |
| Epstein-Barr viral DNA quantification enrollment (n = 218) | |
| Negative or <2000 IU/mL | 203 (93) |
| ≥2000 IU/mL | 15 (7) |
| Age-appropriate absolute lymphocyte count at enrollment, lymphocytes/μL (n = 244) | 240 (98) |
| Age-appropriate immunoglobulin G level, mg/dL (n = 127) | 124 (98) |
| Age-appropriate CD4 count, cells/μL (n = 82) | 71 (87) |
| Immunosuppression at enrollment (n = 275) | |
| Low: monotherapy with tacrolimus (trough <5 ng/mL), sirolimus (trough <5 ng/mL), or cyclosporine (trough <100 ng/mL) | 202 (73) |
| Medium: ≤2 agents and/or tacrolimus plus sirolimus trough between 5 and 8 ng/mL, and/or steroids <0.5 mg/kg per dose | 39 (14) |
| Higha: ≥3 agents and/or tacrolimus plus sirolimus trough >8 ng/mL, and/or steroids ≥0.5 mg/kg/d | 34 (12) |
Abbreviations: MMR, measles-mumps-rubella; VZV, varicella-zoster virus.
a
Immunosuppressive agents used in addition to tacrolimus, sirolimus, cyclosporine, and steroids include azathioprine (5 participants [2%]) and mycophenolate mofetil (19 participants [7%]).