Vaccination in pediatric cancer survivors: Vaccination rates, immune status, and knowledge regarding compliance

Background Vaccination recommendations for childhood cancer survivors are ambiguous. Limited data exist on vaccination rates and patient/caregiver knowledge of vaccination postchemotherapy. Procedure A single-institution study of childhood cancer survivors treated from 1996 to 2018. Study included a retrospective chart review assessing patient's vaccination status, survey of patient's/caregiver's knowledge/beliefs regarding vaccination postchemotherapy, and assessment of immunoglobulin titers. Results A total of 120 patient charts were included. Vaccination records were available for 82% (98/120) of patients, 57% (56/98) were up to date with vaccinations before chemotherapy, and 83% (81/98) received vaccinations after chemotherapy. Children who resumed vaccination postchemotherapy were younger at cancer diagnosis compared to those who did not resume vaccination (2 vs 4 years,P < .02). Median time since chemotherapy was higher in vaccinated versus unvaccinated patients (107 vs 60 months,P < .02). Immunoglobulin titers were assessed in 27 patients, and 74% (20/27) were not immune to one or more infections tested. Lack of immunity to pneumococcal strains was the most common. There was no difference in median age at diagnosis or time since chemotherapy completion in immune versus nonimmune patients. In 33 surveyed patients/caregivers, 33% (11/33) were not advised about resuming vaccinations postchemotherapy. Over one-third (12/33) of respondents were concerned about vaccination safety after chemotherapy, although 88% (29/33) agreed they would vaccinate if recommended by their pediatrician/pediatric oncologist. Conclusions Most childhood cancer survivors resume vaccinations postchemotherapy. Considerable variability exists in vaccination timing after chemotherapy. Pediatric oncologists play a central role in educating patients/pediatricians about vaccination recommendations postchemotherapy.