Comparison on the antibody response after primary immunization of 5 µg and 10 µg hepatitis B vaccine made by recombinant DNA techniques among newborns

Abstract

To compare the antibody response induced by primary immunization with 5 µg and 10 µg hepatitis B vaccine made by recombinant DNA techniques among the newborns. Healthy infants who had completed primary immunization with 5 µg hepatitis B vaccine made by recombinant dexyribonucleic acid techniques in Saccharomyces (Hep-SC) or 10 µg hepatitis B vaccine made by recombinant dexyribonucleic acid techniques in Hansenula polymorpha (HepB-HP) were included in the study. Kids under study were 7-12 months of age and had been on 0-1-6 schedule. Standardized questionnaire was used and blood samples were collected. The titer of antibody to hepatitis B surface antigen (anti-HBs) was detected by Chemiluminescence Microparticle Imunoassay (CMIA). If anti-HBs happened to be under 10 mIU/ml, HBV DNA was further detected by nested-PCR to distinguish occult hepatitis B virus infection. Sero-conversion rate and titer of anti-HBs were compared between the two kinds of hepatitis B vaccines. Multivariate analysis was used to find the relationship between the kind of hepatitis B vaccine as well as the antibody response after debugging the other influencing factors including month-age, gender, birth-weight, premature birth and mother's HBsAg status. 8947 infants vaccinated with 5 µg HepB-SC and 4576 infants vaccinated with 10 µg HepB-HP were investigated. In the 5 µg group, the rates of non-, low-, normal- and high-response were 1.88%, 15.18%, 61.42% and 21.52% respectively. In the 10 µg group, the corresponding rates were 0.15%, 2.16%, 29.42% and 68.26% respectively. The non-, low-, normal-response rates were all higher in 5 µg group than in 10 µg group (P<0.01), while the high-response rate was much higher in 10 µg group than in 5 µg group (P<0.01). The geometric mean concentration (GMC) of anti-HBs were 354.81 mIU/ml (95%CI: 338.84-363.08 mIU/ml) and 1778.28 mIU/ml (95%CI: 1698.24-1819.70 mIU/ml) in the 5 µg group and 10 µg group respectively. The GMC was statistically higher in the 10 µg group than in the 5 µg group (P<0.001). The sero-conversion rate and GMC were significantly different between the two groups even after debugging the other influencing factors. Better anti-HBs response could be achieved by primary immunization with 10 µg HepB-HP than with 5 µg HepB-SC among newborns.