MMR vaccination timing and long‐term immunity among childhood cancer survivors

Long‐term seroprotection against the measles and mumps viruses has not been reported in childhood cancer survivor (CCS) who received two‐lifetime doses of the measles, mumps, and rubella (MMR) vaccine. We performed a retrospective study of measles and mumps titers among 55 CCS who received standard chemotherapy and two MMR vaccinations at any time. Over 75% of CCS who received at least one MMR prior to their cancer diagnosis had a negative or equivocal titer to measles or mumps. In contrast, all CCS who received the MMR series following their cancer treatment demonstrated long‐term seroprotection to both viruses at a mean of 8.2 years after their last vaccination.