British Liver Trust

HBV vaccine induces antibodies to HBsAg. It contains recombinant HBsAg adsorbed on to aluminium hydroxide adjuvant. A combined vaccine containing purified inactivated hepatitis A virus and purified recombinant HBsAg, separately adsorbed onto aluminium hydroxide and
aluminium phosphate, is also available.

It should be pointed out that mercury-based Thiomersal is not used as a preservative in hepatitis B vaccines available in the UK. Thiomersal is still used in the production process for Engerix-B, Twinrix and Fendrix, and therefore residues are present in the final product.

Around 10 to 15 per cent of adults do not respond to three doses of vaccine or respond poorly. Poor responses are identified with individuals older than 40 years, smokers and the obese. Patients with advanced liver disease, who are immunosuppressed or on renal dialysis, also have lower seroconversion rates.

Individuals who are anti-HBs and anti-HBc positive are immune and do not require vaccination.

Specific hepatitis B immunoglobulin (HBIG)
HBIG provides passive immunity and thus can confer immediate, albeit temporary, protection after accidental inoculation with HBV-infected blood. HBIG is obtained from the plasma of immunised and screened human donors. The theoretical risk of transmission of variant CJD from plasma products means that HBIG used in the UK is now prepared from plasma sourced from abroad and as a result supplies are somewhat scarce.

HBIG is given concurrently with HBV vaccine as it does not alter the development of active immunity.

Administration
HBV vaccine is routinely given intramuscularly in the upper arm or anterolateral thigh. The buttocks are not used as absorption may affect the vaccine efficacy. Patients who have bleeding disorders should receive their vaccination by deep subcutaneous injection.

HBIG can be administered in the upper outer quarter of the buttock or the anterolateral thigh.

Schedules for pre-exposure and post-exposure prophylaxis
For pre-exposure prophylaxis in high risk groups, and for post-exposure prophylaxis, an accelerated schedule should be used. The vaccine is given at zero, one and two months. Alternatively, a schedule of zero, one and six months can be used where rapid protection is not required and there is a high likelihood of compliance.

Where compliance may be difficult to achieve (for example, in IDUs and GUM clinic patients) higher completion rates for three doses at zero, one and two months has been reported. An extension to the product licence for Engerix-B has been granted to allow for a very rapid immunisation schedule of three doses given at zero, seven and 21 days. When this schedule is used, a fourth dose should be given 12 months after the first dose. This schedule is licensed for use on occasions where people over the age of 18 are at intermediate risk and a faster induction of protection is necessary.

Post-exposure immunisation
This is particularly recommended for babies born to HBsAg positive mothers, including mothers who have had acute hepatitis B during pregnancy. Hepatitis B infection can be transmitted from infected mothers to their babies by perinatal transmission, conferring a high risk of chronic disease.

Perinatal transmission can be effectively prevented in over 90 per cent of cases by appropriate vaccination starting at birth of all infants born to HBsAg positive mothers. DH guidelines recommend that all pregnant women should be offered screening for hepatitis B infection during each pregnancy. If infection is found, confirmatory testing and testing for HBeAg or anti-HBe should follow. All babies born to these mothers should receive a complete course of vaccine.

Babies born to mothers who have higher levels of virus and are HBeAg positive (i.e. high risk) should receive HBIG as well as active immunisation.

HBIG should be given, if possible, within 24 hours of delivery and needs to be ordered well in advance of the birth. It may be given simultaneously with vaccine but at a different site.

For post-exposure prophylaxis in babies born to HBV-infected mothers, the accelerated immunisation schedule should be used. Babies receive a dose of vaccine at birth followed by doses at one and two months of age and a fourth dose at 12 months.

Testing for HBsAg at one year of age is required to identify any children for whom the intervention has failed and who have become carriers. These children will require on-going assessment and further management.

Vaccination of high-risk groups
Selective hepatitis B vaccination is followed in the United Kingdom, rather than universal vaccination. This is uncommon in developed countries and the policy is being increasingly questioned in the light of its failure to protect target groups.
Selective hepatitis B vaccination of the following high risk groups is recommended: