Efficacy of immunization against hepatitis B virus infection in children with cancer

Background. The purpose of this study was to evaluate the impact of hepatit is B prophylaxis in preventing hepatitis B infection in children with malig nancy. Procedure, Between May, 1993, and September, 1998, a total of 151 ch ildren (95 boys, 56 girls), 29 (19%) with lymphoma, 58 (39%) with leukemia, and 64 (42%) with solid tumor, were screened for hepatitis B Virus (HBV). The mean age was 7.5 +/- 2.5 years. Children with negative serology; receiv ed active and/or passive immunization. HBsAg and anti-HBs were positive pri or to vaccination in 16 (10%) and 17 (11%) children, respectively. One hund red eighteen children (78%) of one hundred fifty-one with negative serology were included in the vaccination program. The vaccine dose was 40 mu g. Ch ildren With solid tumor and lymphoma received recombinant hepatitis B vacci ne at diagnosis, repeated at months 1, 2, and 12. Hyperimmunglobulin was ad ministered monthly in children with leukemia during the intensive chemother apy period. They were then vaccinated following the third month of maintena nce therapy with the schedule described above. Anti-HBs titers were measure d every 3 months, and titers above 10 mlU/ml were accepted as protective. R esults. Anti-HBs positivity after the first three doses was 77% in solid tu mors, 88% in acute leukemia, and 48% in lymphomas. Anti-HBs positivity with respect to diagnosis in children completing the vaccination schedule was 9 4% in solid tumor, 90% in leukemia, and 74% in lymphoma (P > 0.05). Thirty- three percent of children have not received the fourth dose as yet. In tota l 78% of the children developed protective antibody titers with or without the fourth dose, and none was infected with HBV during 3 years of follow-up . Ten (39%) of twenty-six children who remained unresponsive to immunizatio n were infected with HBV. Conclusions. These data reveal that HBV prophylax is is necessary and that our vaccination schedule is effective in preventin g HBV infection in these children. (C) 2000 Wiley-Liss, Inc.