• Vaccine Name: ActHIB
• Target Pathogen: Haemophilus influenzae
• Target Disease: Meningitis
• Product Name: Haemophilus b Conjugate Vaccine (Tetanus Toxoid Conjugate)
• Tradename: ActHIB
• Manufacturer: Sanofi Pasteur, SA
• Vaccine Ontology ID: VO_0000004
• CDC CVX code: 48
• Type: Conjugate vaccine
• Status: Licensed
• Location Licensed: USA (License #1724)
• Host Species for Licensed Use: Human
• Antigen: Haemophilus b capsular polyribosyl-ribitol-phosphate(PRP)- tetanus toxoid
• Preparation: The vaccine consists of the Haemophilus b capsular polysaccharide (polyribosyl-ribitol-phosphate, PRP), a high molecular weight polymer prepared from the Haemophilus influenzae type b (HiB) strain 1482 grown in a semi-synthetic medium, covalently bound to tetanus toxoid. The tetanus toxoid is prepared by extraction, ammonium sulfate purification, and formalin inactivation of the toxin from cultures of Clostridium tetani (Harvard strain) grown in a modified Mueller and Miller medium. The toxoid is filter sterilized prior to the conjugation process. When ActHIB vaccine is reconstituted with saline diluent, each single dose of 0.5 mL is formulated to contain 10 μg of purified capsular polysaccharide conjugated to 24 μg of inactivated tetanus toxoid, and 8.5% of sucrose (ActHIB 2005).
• Immunization Route: Intramuscular injection (i.m.)
• Virulence: Not virulent
• Storage: 2° to 8°C (35° to 46°F). DO NOT FREEZE.
• Approved Age for Licensed Use: Infants and children ages 18 months to 2 years old (ActHIB 2005).
• Contraindication: The vaccine should not be administered to anyone with a known hypersensitivity to any component of the vaccine (FDA: ACTHIB).
• Description: ActHIB vaccine was among the first conjugated Hib vaccines developed at the National Institutes of Health (NIH). It is now manufactured by Sanofi Pasteur SA in Lyon, France. The conjugation process changes the polysaccharide from a “T-cell–independent antigen” to a “T-cell–dependent antigen”, which greatly improves immunogenicity, particularly in young children. In addition, repeated doses elicit a substantial booster response in children who have been previously vaccinated (ActHIB 2005).

Human Response

• Vaccination Protocol: ActHIB vaccine is indicated for active immunization of infants and children 2 through 18 months of age for the prevention of invasive disease caused by H influenzae type b.
  
  The number of doses of ActHIB vaccine indicated depends on the age at which immunization is begun. For previously unvaccinated children, the first, second, third and fourth dose were given at 2, 4, 6, and 12 to 18 months. A child 7 to 11 months of age should receive 2 doses at 8-week intervals and a booster dose at 15 to 18 months. A child 12 to 24 months of age should receive 1 dose and a booster dose 2 months later. Preterm infants should be vaccinated according to their chronological age from birth (ActHIB 2005).
  
  ActHIB vaccine reconstituted with the saline diluent (0.5 mL per dose) should be administered intramuscularly in the outer aspect of the midthigh or deltoid. Do not inject intravenously. It should not be injected into the gluteal area or areas where there may be a nerve trunk. When administering multiple vaccines during a single visit, separate injection sites and syringes should be used. Administer ActHIB vaccine within 24 hours after reconstitution (ActHIB 2005).
• Side Effects: The most common side effects with ActHIB vaccine may include redness, swelling, and tenderness where the injection was given; fever, fussiness, and drowsiness. Other side effects may occur. ActHIB vaccine should not be given to children who have had a serious allergic reaction (anaphylactic reaction) after a previous dose of the vaccine. When administering an intramuscular injection, like ActHIB vaccine, to people with bleeding disorders, caution should be exercised because they may develop a serious bruise or collection of blood at the injection site (ActHIB 2005).
• Efficacy: Two clinical trials supported by the National Institutes of Health (NIH) compared the anti-PRP (polyribosyl-ribitol-phosphate) antibody responses to three Hib conjugate vaccines in racially mixed populations of children. In these trials, ActHIB vaccine consistently produced high rates of seroconversion (83% to 97%) to antibody levels that correlate with long-term protection (>1.0 µg/mL) following the 3-dose primary series (Decker et al., 1992). Consistently high rates of seroconversion (83% to 99%) with an ActHIB vaccine 3-dose primary series were also obtained in 11 non-comparative clinical trials (N=1225) (Fritzell et al., 1992). Additionally, three NIH trials demonstrated that ActHIB vaccine produced consistently high geometric mean anti-PRP antibody titers (Decker et al., 1992).