Administration of live attenuated varicella vaccine to children with cancer before starting chemotherapy.
From July 1985 to February 1987, of 46 consecutive children with cancer (26 male, 20 female; median age, 4 years) with no prior history of chickenpox, the initial 30 patients were randomized either to receive or not to receive live attenuated varicella vaccine (LAVV) before chemotherapy was started and the remaining 16 patients were all immunized without randomization. Before immunization, Varicella zoster (VZ) antibodies were detected by immunofluorescence and ELISA in 11 (34%) of 32 vaccinated children and two (14%) of 14 controls, indicating previous infection. A booster effect was evident in 70% of them and no side effects were noted. Ten (28%) of 32 vaccinees were excluded from the analysis because of early death due to cancer (1-4 weeks). Seroconversion was demonstrated in ten (77%) of 13 vaccinees, with high antibody titres. Only three of them lost their antibodies 2 years after immunization, as disclosed by serological follow-up. Eight out of 13 vaccinees had household contacts with VZ and none became infected. Zoster immunoglobulin (ZIG) was never given. Among controls, seven out of 14 were exposed to VZ and four (57%) became infected. Mild side effects were observed in four (12.5%) out of 32 vaccinees (three with papulovesicular rash, 6-30 lesions, and one with a 3-day intermittent fever). Local reactions, zoster and spreading of vaccinal virus did not occur. LAVV proved to be safe and effective when administered before starting chemotherapy to children with cancer and no history of varicella.