Methods
Cedars-Sinai Medical Center (CSMC) Institutional Review Board approved this retrospective study. The data from 28 patients, less than 21 years old, who underwent a minimum of 3 months of chemotherapy was collected from a list of CCS followed at CSMC (Los Angeles, CA) between January 1, 2010 and July 31, 2022, see table 1. Confirmation of primary vaccine series completion, either through available vaccination records or documentation in a physician note, was required to be included in the study. Exclusion criteria included relapsed disease, HSCT, or having received intravenous immunoglobulin (IVIG) within 6 months of the titer collection. All redrawn samples that occurred within 3 months of the original titer collection were grouped together. Serum antibody levels for measles, mumps, rubella, varicella, tetanus, and hepatitis B were measured between 1 month and 30 months after the conclusion of chemotherapy.
Table 1: Patient demographic, diagnosis, and duration of treatment