Contents

6 Haemophilus influenzae type b (Hib) disease

6.4 Vaccines

The only way to reliably protect against Hib disease is immunisation. Antibodies to PRP (polyribosylribitol phosphate), a component of the polysaccharide cell capsule of Hib, are protective against invasive Hib disease. To induce a T-cell dependent immune response, the PRP polysaccharide has been linked (conjugated) to a variety of protein carriers. These conjugate Hib vaccines are immunogenic and effective in young infants (see also section 1.2.3). The protein carriers used are either an outer membrane protein of Neisseria meningitidis (PRP-OMP Hib vaccine), a mutant diphtheria toxin (Hb-OC Hib vaccine) or a tetanus toxoid (PRP-T Hib vaccine).

Note that the protein conjugates used in Hib vaccines are not themselves expected to be immunogenic and do not give protection against N. meningitidis, diphtheria or tetanus.

6.4.1 Available vaccines

Funded vaccines

The Hib vaccines funded as part of the Schedule are:
  • Hib-PRP-T, given as the hexavalent vaccine DTaP-IPV-HepB/Hib (Infanrix-hexa, GSK): contains diphtheria, tetanus, acellular pertussis, inactivated polio, hepatitis B and Haemophilus influenzae type b vaccine (see section 5.4 for more information)
  • ​Hib-PRP-T given as monovalent Hib vaccine (Act-HIB, Sanofi-aventis NZ Ltd): contains 10 µg of purified Hib capsular polysaccharide conjugated to 18–30 µg of inactivated tetanus toxoid; other components (excipients) include trometamol, sucrose and sodium chloride.

Other vaccines

Hib-PRP-T (Hiberix, GSK) is also registered (approved for use) and is available (marketed) in New Zealand. It contains 10 µg of purified Hib capsular polysaccharide conjugated to 30 µg of inactivated tetanus toxoid. Other components (excipients) include lactose in the vaccine and sterile saline solution in the diluent.

6.4.2 Efficacy and effectivenessTop

The high efficacy and effectiveness of Hib vaccines have been clearly demonstrated by the virtual elimination of Hib disease in countries implementing the vaccine,3–5 including New Zealand. Hib vaccines are highly effective after a primary course of two or three doses.6–8 Disease following a full course of Hib vaccine is rare.

Conjugate vaccines reduce carriage in immunised children and as a result also decrease disease in unimmunised people (herd immunity). These vaccines will not protect against infection with NTHi strains of H. influenzae, and therefore do not prevent the great majority of otitis media, recurrent upper respiratory tract infections, sinusitis or bronchitis.

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

Duration of immunity

A primary series followed by a booster dose in the second year of life should provide sufficient antibody levels to protect against invasive Hib disease to at least the age of 5 years.9

6.4.3 Transport, storage and handlingTop

Transport according to the National Guidelines for Vaccine Storage and Distribution.10 Store at +2oC to +8oC. Do not freeze.

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

DTaP-IPV-HepB/Hib vaccine (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.

Hib-PRP-T vaccine (Act-HIB) must be reconstituted with the supplied diluent and used immediately after reconstitution.

6.4.4 Dosage and administrationTop

The dose of DTaP-IPV-HepB/Hib and Hib-PRP-T vaccines is 0.5 mL administered by intramuscular injection (see section 2.3).

Co-administration

DTaP-IPV-HepB/Hib and Hib-PRP-T vaccines can be co-administered with other routine vaccines on the Schedule, in separate syringes and at separate sites. (See also section 14.4.4 for information about co-administration of DTaP-IPV-HepB/Hib and PCV13.)