... characteristics, such as HBV DNA or ALT levels [41]. 5. Occult Hepatitis B Occult hepatitis B is defined by the presence of < /b> HBV DNA in serum or liver in the absence of < /b> HBsAg [42,43]. Serum HBV level < /b> is usually ... vaccine, became available in 1982. Consequently, the second generation of < /b> HB vaccine, a DNA recombinant HB vaccine was also available for general use in 1986. Both of < /b> the vaccines were proven to be ... 11. Bancroft WH, Snitbhan R, Scott RM, Tingpalapong M, Watson WT, Tanticharoenyos P, et al. Transmission of < /b> hepatitis B virus to gibbons by exposure to human saliva containing hepatitis B surface...