Evaluation of immunogenicity of an immune complexed hepatitis B vaccine / 中华微生物学和免疫学杂志

ABSTRACT

Objective To evaluate the immunogenicity of an immune complexed hepatitis B vac-cine ( HBsAg-HBIG immune complexes , IC) in mouse and cynomolgus monkeys by using recombinant hepa-titis B vaccine ( Saccharomyces cerevisiae, HBsAg) as the control .Methods BALB/c mice were vaccinated with single dose of IC and single dose of HBsAg respectively and then serum samples were collected at differ -ent time points for the detection of dynamic anti-HBs by using ELISA .The serum anti-HBs titers in BALB/c mice vaccinated with different immunization strategies were also analyzed .ELISPOT assay was performed to detect the numbers of IFN-γSFC and IFN-γpositive rate in splenocytes of BALB/c mice intramuscularly im-munized with IC, HBsAg or standard hepatitis B vaccine at 5μg/mouse.ED50 was measured to evaluate the stability of IC.Twelve cynomolgus monkeys were equally divided into two groups and immunized with high dose (100 μg) and low dose (20 μg) of IC respectively and then , serum anti-HBs levels at different time points were detected .Results The serum anti-HBs titers in IC immunized group at different time points were higher than those immunized with HBsAg .Moreover, the anti-HBs titer induced by two doses of IC reached a level comparable to that elicited by three doses of HBsAg .ELISPOT assay showed that both the numbers of IFN-γSFC and IFN-γpositive rate were the highest in IC immunized group as compared with those immunized with HBsAg and standard hepatitis B vaccine .IC had a lower ED50 than HBsAg, indicating a good long term stability .Cynomolgus monkeys immunized with high or low dose of IC produced high levels of anti-HBs titer during a long time period .Conclusion IC has a higher immunogenicity inducing both hu-moral immunity and cellular immunity as compared with HBsAg or standard hepatitis B vaccine .