Use in existing thrombocytopenia may result in more severe reduction in platelets (avoid use in previous history of postvaccination thrombocytopenia). Severe allergic reactions including anaphylaxis reported rarely. Use with extreme caution in immediate-type hypersensitivity reactions to eggs. Vaccine should not be administered to severely immunocompromised persons with exception of asymptomatic children with HIV. Severely immunocompromised patients and symptomatic HIV-infected patients exposed to measles should receive immune globulin, regardless of prior vaccination status. Patients with minor illnesses (diarrhea, mild upper respiratory tract infection with or without low grade fever or other illnesses with low-grade fever) may receive vaccine. Leukemia patients in remission and who have not received chemotherapy for at least 3 months may be vaccinated. Use with caution in history of cerebral injury, convulsions, or other conditions where stress due to fever should be avoided.