Application of a live varicella vaccine in children with acute leukemia or other malignant diseases.

A live varicella vaccine was used in 11 susceptible children in remission from acute leukemia, ten of whom had been in remission for six months or less, and in 6 children with neuroblastoma and retinoblastoma. In the immunological checkup before vaccination, most of them showed a positive reaction in the skin tests with dinitrochlorobenzene, phytohemagglutinin, purified protein derivative, and viral antigens. Leukopenia (three cases, less than 3,000/cu mm) and decreased IgG level (two cases, 380 mg/dl and 445 mg/dl) were observed in the children with leukemia. Anticancer medication was suspended from one week before vaccination to one week after vaccination. The only clinical reaction was a minute rash that appeared three weeks after vaccination in two children with leukemia and that disappeared within three days. Serological responses by complement fixing and neutralizing (NT) tests were detected in all the vaccinated children four weeks after vaccination, and NT antibody was still detected 28 months after vaccination in the two patients tested. Three of the vaccines were exposed to natural varicella at home and in the classroom 2 to 18 months after vaccination, but they were free from any varicella symptoms.