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.

Immune memory to hepatitis B persists in children aged 7–8 years, who were vaccinated in infancy with 4 doses of hexavalent DTPa-HBV-IPV/Hib (Infanrix™ hexa) vaccine

“…The immunogenicity and tolerability of DTPa-HBV-IPV/Hib has been extensively documented in clinical trials, and through 12 y of post-marketing experience. 6,7 Combining the hepatitis B surface antigen (HBsAg) with other vaccines routinely administered in infancy promotes higher coverage than can be achieved using monovalent vaccines, or through vaccination programmes targeting adolescents and atrisk groups. [8][9][10] HBV vaccination is important even in countries of low endemicity, where a proportion of chronic disease cases arise through perinatal or early childhood infections.…”

Use of basophil activation test in the investigation of adverse effects to vaccines

“…At present, the diagnostic and predictive values of in vitro tests exploring immediate (specific IgE determination, histamine and leukotriene release tests, basophil activation test) and non-immediate type (lymphocyte activation tests and cytokine assays in the supernatant of activated blood mononuclear cells) of vaccine adverse effects are not yet validated but might address research on vaccine side-effects and improve both diagnostic approaches and our understanding of immune response to vaccination. A cellular test, such as a basophil activation test, or more widely a flow cytometry analysis of immune cells, might add new insights to the comprehension of immunotherapy, 13 as immunotherapy can be considered a vaccination, for certain aspects. Basal mechanisms underlying the mode of action of allergen-specific immunotherapy include many steps comparable to the immune response to vaccine: a modulation of T-and B-cell responses and related antibody isotypes, the migration of inflammatory cells to tissues and the involvement of Th1/Th2 balance and T-regulatory cells as key regulators of peripheral tolerance to allergens 16 and allergen immunotherapy, as vaccination, certainly focuses onto the role of innate cells in the therapeutic outcome.…”