Comparison of separate and mixed administration of DTPw-HBV and Hib vaccines: Immunogenicity and reactogenicity profiles

AbstractObjective: To investigate the immunogenicity, safety and tolerability of three doses of a pentavalent vaccine produced by extemporaneous mixing of diphtheria-tetanus-whole cell pertussis-hepatitis B virus (DTPw-HBV) and a lyophilized Haemophilus influenzae type b (Hib)-tetanus conjugate vaccine in one syringe in comparison with separate, concomitant administration of the same vaccine components in healthy infants at 1.5, 3, and 5 months of age, following a dose of hepatitis B vaccine at birth.Methods: An open, randomized, controlled trial was undertaken with 269 children allocated to two groups to receive three doses of Hib and DTPw-HBV vaccines as either a syringe mix or as separate injections in opposite arms. Symptoms were solicited on 4-day diary cards to assess reactogenicity and immunogenicity based on serum samples drawn immediately before the first dose and 1 month after the third dose.Results: There were fewer local and more general symptoms in the mixed vaccine group, but no statistically significant difference in reactogenicity between the two groups. There were no withdrawals due to adverse experiences. Seropositivity rates were similar for all antigens in the two groups, with no clinically relevant differences in titers.Conclusions: The mixed DTPw-HBV Hib vaccine was safe and well-tolerated, with high immunogenicity against all component antigens, and can be used to provide primary vaccinations of infants while increasing comfort