EFFICACY OF HEPATITIS-B VACCINES WITH AND WITHOUT PRES2-REGION PRODUCT IN SUMO WRESTLERS IN JAPAN

One hundred and twenty Sumo wrestlers in Japan received 20 mu g of a h epatitis B vaccine containing 20% (w/w) preS2-region product, while th e other 181 received 10 mu g of the vaccine without preS2-region produ ct, four times during 20 months. They were followed for antibody to he patitis B surface antigen (anti-HBs) by passive hemagglutination up to 32 months after the first vaccination. The seroconversion to anti-HBs occurred more frequently in the wrestlers receiving preS2-plus vaccin e than in those receiving preS2-minus vaccine at the end of observatio n (87% vs. 66%, P < 0.001). Among the seroconverters, anti-HBs titers were higher ill the wrestlers with FreS2-plus than preS2-minus vaccine s (geometric mean hemagglutination titer (2(N)): 4.0 +/- 1.8 vs. 3.1 /- 1.6, P < 0.001). In 27, 83 and ten wrestlers of light (less than or equal to 100 kg), middle (101-150 kg) and heavy(> 150 kg) weight who received preS2-plus vaccine, the seroconversion occurred in 96%,, 86% and 70%, respectively. In 43, 123 and 15 wrestlers of light, middle an d heavy weight receiving preS2-minus vaccine, by contrast, seroconvers ion occurred in 81%, 60% and 67%, respectively. These results indicate that seroconversion to anti-HBs in Sumo wrestlers would be more effic ient with preS2-plus than preS2-minus vaccines, and that the efficacy would be inversely correlated with the body weight. It remains to be s een whether an enhanced efficacy of the preS2-plus vaccine was due to the inclusion of preS2-region product or to the amount of S-gene produ ct that was 1.6 times greater than in the preS2-minus vaccine. (C) 199 8 Elsevier Science Ireland Ltd. All rights reserved.