Six-component vaccines: new preparations. Simpler hepatitis B vaccination of infants.

(1) Two six-component vaccines available in France (Hexavac and InfanrixHexa) are designed for primary and booster vaccination of infants. A single intramuscular injection delivers a five-component vaccine (diphtheria, tetanus, poliomyelitis, Haemophilus influenzae type b and acellular pertussis) and a hepatitis B vaccine. (2) The clinical evaluation dossier on InfanrixHexa includes four trials versus separate injections of a five-component vaccine and a hepatitis B vaccine at two distinct sites. (3) For primary vaccination, no difference in immunogenicity was found between InfanrixHexa and separate vaccination for 5 of the 6 components. The serological response to Haemophilus was weaker with InfanrixHexa, but whether or not this translates into worse long-term clinical protection is unknown. (4) After primary vaccination, major adverse events were a little rarer with InfanrixHexa than with separate vaccination. There was no difference in adverse events between InfanrixHexa and separate vaccination after the recommended booster between the ages of 16 and 18 months. (5) Evaluation data on Hexavac published by Aventis Pasteur MSD are very limited. We found only one trial in the primary vaccination setting, versus vaccination at two distinct sites with a five-component vaccine and a hepatitis B vaccine. (6) The serological response to hepatitis B virus and Haemophilus was significantly weaker with Hexavac than with separate vaccination, but no difference was found regarding the other four components. It is not known if this difference has any clinical implications. There was no difference in adverse events between Hexavac and separate vaccination. (7) The vaccination schedule depends on whether or not separate hepatitis B vaccine is required at birth. A six-component vaccine and a five-component vaccine can be used alternately.