Immunogenicity and Reactogenicity following Primary Immunisation with a Combined DTaP-HBV Vaccine and a Haemophilus influenzae Type B Vaccine Administered by Separate or Mixed Injection

• Published in: Clinical drug investigation 2005, Vol.25 (5), p.315-323
• Main Authors: Gabutti, G, Bona, G, Dentico, P, Bamfi, F, Hardt, K, Majori, S, Crovari, P
• Format: Article
• Language: English
• ISSN: 1173-2563
• DOI: 10.2165/00044011-200525050-00004

The aim of this open, randomised, multicentre trial was to evaluate the immunogenicity and reactogenicity of the tetravalent diphtheria-tetanus-acellular pertussis-hepatitis B (DTaP-HBV) vaccine when given either as a mixed or as a separate concomitant injection with the Haemophilus influenzae type b (Hib) vaccine at 3, 5 and 11 months of age. Antibody against diphtheria, tetanus, pertussis (ELISA), hepatitis B (radioimmunoassay) and Hib polyribosylribitol phosphate (PRP) [radiolabeled antigen binding assay] was determined. Solicited local and systemic adverse events were evaluated on the day of each vaccination and for three subsequent days. Follow-up of unsolicited and serious adverse events was conducted for 30 days following each vaccination. A total of 360 subjects were enrolled in the study. After completion of the three-dose vaccination course, seroprotective antibody concentrations against diphtheria, tetanus and hepatitis B, together with a pertussis vaccine response, were seen in almost all subjects with immunogenicity results (n = 336). All subjects had post-vaccination Hib anti-PRP antibody concentrations of at least 0.15 mug/mL, and 97.0% and 99.4%, respectively, of the subjects receiving a single or separate injections had Hib anti-PRP antibody concentrations >/=1.0 mug/mL. Addition of the Hib vaccine to the tetravalent DTaP-HBV vaccine did not increase the incidence of local or systemic reactions. Combination of DTaP-HBV and Hib vaccines in a single injection is safe, immunogenic and well tolerated, and thus has the potential to simplify the childhood immunisation schedule in Italy.