Post-Chemotherapy Titer Status and Need for Revaccination After Treatment for Childhood Cancer

Objectives. To evaluate the strategy of checking vaccine titers after completion of chemotherapy. Study Design. Retrospective review of pediatric oncology patients who completed chemotherapy. Demographics, post-chemotherapy titers, and absolute lymphocyte counts (ALCs) were analyzed. Results. Ninety patients met inclusion criteria, and 87% of patients had at least one titer checked. Comparing patients <7 years and those ≥7 years at diagnosis, there was no difference in incidence of negative titers except mumps; those <7 years old were more likely to have negative titers (58% vs 20%, P = .003). Comparing those <13 years old to ≥13 years old, there was no difference in negative titers except mumps (45% vs 19%, P = .02) and tetanus (44% vs 0%, P = .002). No patient maintained all protective titers after completion of chemotherapy. Time to ALC recovery was not predictive of positive titers. Conclusion. Checking titers after chemotherapy is not recommended. Providers should assume loss of immunity.