Contents

8 Hepatitis B

8.4 Vaccines

8.4.1 Available vaccines

A number of HBV-specific monovalent and combination vaccines that contain HBV vaccine are licensed (approved for use) and available (marketed) in New Zealand, all of which contain HBsAg that has been synthesised by genetically modified yeast or bacterial cells.

Funded vaccines

The hepatitis B-containing vaccines funded as part of the Schedule are:
  • Hep B (HBvaxPRO, MSD): contains either 5 µg, 10 µg or 40 µg of hepatitis B surface antigen per dose; it does not contain a preservative
  • ​DTaP-IPV-HepB/Hib (Infanrix-hexa, GSK): diphtheria, tetanus, acellular pertussis, inactivated polio, hepatitis B and Haemophilus influenzae type b vaccine (see section 5.4.1 for more information).

Other vaccines

Other hepatitis B-containing vaccines licensed and available are:

8.4.2 Efficacy and effectivenessTop

See also section 14.4.2 for information about the DTaP-IPV-HepB/Hib vaccine.

Immunogenicity

Clinical trials in high-risk groups have shown a vaccine efficacy of 85–95 percent. Immunity is strongly correlated with post-vaccination serum anti-HBs antibody levels of ≥10 IU/L (see also the note in section 8.5.5). Individuals who have had a documented seroconversion after three injections are expected to have lifelong immunity with no need for further boosters, even if circulating antibody is subsequently not detectable.

Smoking, obesity, HIV infection and chronic disease (including renal failure) all reduce vaccine efficacy, but age is the primary factor affecting the response. At least 98 percent of infants, 95 percent of children and 90 percent of adolescents develop protective levels of antibody after three doses of vaccine. Some non-responders to the initial vaccination course will produce adequate antibody levels after a further booster dose of vaccine or a full second course.

However, some people are persistent non-responders. Persistent non-responders often have an impaired immune system, such as organ transplant recipients and those with HIV infection or chronic disease, including advanced cirrhosis, renal failure or those undergoing haemodialysis (see section 8.5.5).

For babies of HBeAg-positive mothers, controlled trials have shown that vaccine at birth provides 75 percent protection from infection, while administration of HBIG in addition to vaccination provides 85–95 percent protection against transmission.1, 17 Protection is reduced to less than 80 percent when the mother’s HBV DNA level is greater than 108 IU/mL (or 108 copies/mL). In this situation, administration of tenofovir (an antiviral agent) to the mother during the last trimester is recommended and funded.

Duration of immunity

The development of anti-HBs antibodies after a primary vaccination course (seroconversion) indicates development of immune memory. The quantity of antibody in serum is thought to determine the length of time the antibody titre can be detected in the blood, although any reading ≥10 IU/L is considered protective (see also the note in section 8.5.5). Once a seroprotective level is reached after the primary vaccination course, booster doses of vaccine are unnecessary.18, 19 Children who are given booster doses up to 12 years after the primary series show strong anamnestic (secondary) responses, indicating the boost was likely to have been unnecessary.

There is evidence from Taiwan,20 Alaska21 and Hawaii22 that boosters of hepatitis B vaccine are unnecessary following completion of infant immunisation. This is despite the fact that a large proportion of vaccinees will lose detectable antibodies within seven years of vaccination. Long-term protection from clinical infection despite loss of neutralising antibody is thought to reflect a strong cellular memory immune response following HBV vaccination. Vaccinees who are subsequently infected with HBV do not develop clinical illness but may have anti-HBc present in plasma.

Effects on chronic HBV infection

In all populations where it has been measured, immunisation has led to a dramatic drop in HBV chronic infection.23 For example, chronic HBV infection dropped from 16 percent to zero in Alaska as a result of 96 percent immunisation coverage. In Taiwan, the incidence of hepatocellular carcinoma also decreased in children as a result of the immunisation programme.24, 25

8.4.3 Transport, storage and handlingTop

Transport hepatitis B vaccines according to the National Guidelines for Vaccine Storage and Distribution.26 Store at +2oC to +8oC. Do not freeze.

DTaP-IPV-HepB/Hib should be stored in the dark.

DTaP-IPV-HepB/Hib (Infanrix-hexa) must be reconstituted by adding the entire contents of the supplied container of the DTaP IPV-HepB vaccine to the vial containing the Hib pellet. After adding the vaccine to the pellet, the mixture should be shaken until the pellet is completely dissolved. Use the reconstituted vaccine as soon as possible. If storage is necessary, hold at room temperature for up to eight hours.

8.4.4 Dosage and administrationTop

The dose of DTaP-IPV-HepB/Hib (Infanrix-hexa) is 0.5 mL administered by intramuscular injection (see section 2.3).

The dose of Hep B vaccine varies according to the age of the individual (see Table 8.2 for Hep B [HBvaxPRO] dosage and scheduling information). Hep B vaccine is administered by intramuscular injection. In special circumstances Hep B vaccine may be given intradermally to increase the immune response (see ‘Non-responders to vaccination’ in section 8.5.5).

Co-administration with other vaccines

Hepatitis B vaccines may be given at the same time as all other vaccines on the Schedule, including measles, mumps and rubella (MMR) vaccine. (See also section 14.4.4 for information about co-administration of DTaP-IPV-HepB/Hib and PCV13.) 

If a course of vaccine is interrupted, it may be resumed without repeating prior doses (see Appendix 2).