Aim

The aim of the study was to evaluate immune reconstitution before making deci¬sions of revaccination for patients after haematopoietic stem cell transplantation (HSCT). The reasons for the derogations from our algorithm were also analyzed.

Patients

The study included 81 patients aged 1.5 to 25.2 years, with 31 women and 50 men, and 55 allo-HSCT and 26 auto-HSCT patients. We analyzed time and degree of immunological reconstitution after HSCT and decisions that have been made with respect to revaccination, its postponement or implementation of immunoglobulin substitution.

Results

Time between HSCT and immunological assessment ranged from 5.1 to 27.4 months (median 11 months, including 8.6 months after auto-HSCT and 11.5 months after allo¬HSCT). For patients for whom auto-HSCT was the last phase of oncological treatment, this median time was 6.7 months. Evaluation of immune system up to 8 months after HSCT was performed for 15/81 (18.5%) patients. Among the remaining 66 patients, the most common cause of delay was immunosuppression (22.7%), and in 16/66 (24.2%) cases, no cause was found in the medical records. After first evaluation of the immune system, 64/81 (79%) patients were advised to resume vaccination.

Conclusions

Immunological reconstitution analysis after HSCT was delayed in 81.5% of patients. In order to improve the effectiveness of the post-HSCT vaccination program, it seems appropriate to accelerate the first immunological evaluation and to differentiate the recommendations according to the type of transplantation and post-HSCT therapy, i.e. 3–6 months after auto-HSCT or last phase of oncological treatment and 6-12 months after allo-HSCT.