Measles and rubella antibody status in previously vaccinated children with cancer.

Measles and rubella antibody status were determined by ELISA for 115 previously vaccinated children with cancer. Seventy subjects were receiving chemotherapy, and 45 had successfully completed treatment for their malignancy. Overall, 18% of the subjects were seronegative for measles antibody and 8% for rubella antibody. Only 3% of patients lacked both. In general, seronegative individuals were over age 10 years. Subjects born before 1976 were significantly more likely to be seronegative to measles, 29% vs. 11% (P = 0.02) and to rubella, 16% vs. 4% (P = 0.03) than those born afterwards. Antibody status showed no apparent relationship to the duration of anticancer therapy. Stored serum samples were available for nine seronegative subjects, of whom five were initially seropositive and then lost antibody during or after the completion of anticancer therapy. Our observations suggest that cancer and its associated therapy interfere with antibody production. In view of the increasing survival rates for childhood cancers, additional studies are needed to assess the immune status of these subjects for all vaccine-preventable infections. Pending the outcome of further studies, we suggest that long-term survivors, particularly those born before 1976, or known to be vaccinated at less than 13 months of age, be tested after the completion of therapy for antibody to measles and rubella (and mumps). Also, immune serum globulin should be considered for any previously immunized patient with a close exposure to an active case of measles.