Genvac-B Special Precautions

Because of the period of latency of Hepatitis B infection it is possible for unrecognised infection to be present at the time of immunisation. The vaccine may not prevent Hepatitis B infection in such cases.
The vaccine will not prevent infection caused by other agents such as hepatitis A, hepatitis C and hepatitis E and other pathogens known to infect the liver.
The immune response to Hepatitis B vaccines is related to age. In general, people over 40 years of age respond less well.
In haemodialysis patients and persons with an impaired immune system, adequate anti-HBs antibody titres may not be obtained after the primary immunisation course and such patients may therefore require administration of additional doses of vaccine (see Dosage recommendation for Immunocompromised persons under Dosage & Administration).
As with all injectable vaccines, appropriate medication (e.g. adrenaline) should always be readily available for treatment in case of rare anaphylactic reactions following the administration of the vaccine.
Hepatitis B vaccine should not be administered in the gluteal muscle or intradermally since this may result in a lower immune response.
Hepatitis B vaccine may be used to complete a primary immunisation course started either with plasma-derived or with other genetically-engineered Hepatitis B vaccines, or as a booster dose in subjects who have previously received a primary immunisation course with plasma-derived or with other genetically-engineered Hepatitis B vaccines.