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New approaches to hepatitis A and B vaccines
Author(s) -
Iwarson STEN
Publication year - 1995
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1699-0463.1995.tb01114.x
Subject(s) - virology , immunization , hepatitis b , medicine , hepatitis b virus , hepatitis , hepatitis a , recombinant dna , immunology , antigen , antibody , hepatitis b vaccine , biology , virus , gene , hbsag , biochemistry
Plasma‐derived vaccines and yeast‐derived recombinant vaccines against hepatitis B virus (HBV) infection have gained an acceptable record of efficacy. However, non‐ or hyporesponsiveness to immunization does not only occur in cases of obesity, renal failure or immune suppression, but also in healthy individuals. There is therefore a rationale for developing more immunogenic vaccines against HBV especially for those populations who are potential non‐ or hyporesponders. Currently used recombinant hepatitis B vaccines consist of antigen particles assembled with the product of 226 amino acids encoded in the S gene. Since proteins encoded in the pre‐S gene are also incorporated in the HBV envelope, pre‐S gene products should, at least in theory, be useful in improving protection with hepatitis B vaccines. Inactivated hepatitis A vaccines are more potent than currently used hepatitis B vaccines. Two injections of a standard dose of HAVRIX (SB) by the intramuscular route, or even a single injection using a higher dose (HAVRIX 1440), will achieve protective levels of antibodies. Therefore, increased potency is not essential with inactivated hepatitis A vaccines. New hepatitis A vaccines are likely to be recombinant or attenuated live types. Another aspect of the improvement of existing hepatitis A and B vaccines is unification into a combined form.