Does concomitant injection of a combined diphtheria-tetanus-acellular pertussis -: hepatitis B virus -: inactivated polio virus vaccine influence the reactogenicity and immunogenicity of commercial Haemophilus influenzae type b conjugate vaccines?

The immunogenic responses and local reactions to four Haemophilius influenzae type b (Hib) conjugate vaccines licensed for primary immunisation (Hiberix, ActHib, Pedvax, HibTITER) when administered concomitantly but in the opposite thigh with a candidate diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus vaccine were studied in 549 healthy infants at 3, 4.5 and 6 months of age. Local reactions were mild, but different between the four groups, a tetanus conjugate I-Iib vaccine showing the fewest reactions. All local reactions resolved without sequelae. There was no apparent general reaction. The immunogenic response was similar with all four vaccines, geometric mean concentrations ranging from 4.95 to 7.2 mu g/ml. All but one subject had anti-polyribosylribitol phosphate polysaccharide antibody titres greater than or equal to 0.15 mu g/ml, and 88.0% to 96% achieved high titres (>1.0 mu g/ml) generally associated with long-term protection against Hib disease. Conclusion There does not appear to be any interference with the immune response when current commercial Haemophilus influenzae type b conjugate vaccines are concomitantly administered with a candidate diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio virus vaccine as separate injections.