Spotlight on DTPa-HBV-IPV/Hib Vaccine (Infanrix hexa™)†

Abstract

Infanrix hexa, administered intramuscularly, is a diphtheria, tetanus, acellular pertussis, hepatitis B (HBV), inactivated poliomyelitis and Haemophilus influenzae type b (Hib) conjugate vaccine, indicated for primary and booster vaccination of infants. Infanrix hexa should be administered as a two- or three-dose primary vaccination course in infants aged < or =6 months, followed by booster vaccination between 11 and 18 months of age, with an interval of at least 6 months between the last dose of primary vaccination and the booster dose. This spotlight reviews the immunogenicity and protective effectiveness, as well as the reactogenicity and safety of Infanrix hexa. Infanrix hexa as primary and booster vaccination was safe and highly immunogenic for all its component toxoids/antigens in infants aged <2 years, regardless of vaccination schedules. Its immunogenicity and safety profiles were generally similar to those of currently available vaccines, the diphtheria, tetanus and acellular pertussis-based pentavalent vaccines plus monovalent HBV or Hib vaccines. In large clinical studies, Infanrix hexa elicited a strong immune response against vaccine toxoids/antigens, as indicated by high seroprotection/seropositivity/vaccine response rates and geometric mean titers. Moreover, antibodies against vaccine toxoids/antigens persisted for up to a mean of approximately 6 years after booster vaccination, and the vaccine induced long-term immune memory against hepatitis B surface antigen and Hib antigen. A strong immune response against Infanrix hexa toxoids/antigens after primary vaccination was also induced in infants who had received a dose of HBV vaccine at birth and in pre-term infants, although the response in the latter group was somewhat lower than that in full-term infants. In addition, when coadministered with other childhood vaccines, the immunogenicity of Infanrix hexa or that of the concomitantly administered vaccine was generally not altered. Hexavalent vaccines, including Infanrix hexa, were protective against invasive Hib disease; Infanrix hexa is also expected to be protective against pertussis. Most solicited local and general symptoms with Infanrix hexa were mild to moderate in intensity and the vaccine was associated with few unsolicited adverse events. Available clinical data from more than 10 years' experience with the vaccine suggest that Infanrix hexa as primary and booster vaccination is a safe and useful option for providing protection against the common childhood diseases of diphtheria, tetanus, poliomyelitis, pertussis, hepatitis B and invasive Hib disease.