Hexavalent vaccines: increasing options for policy-makers and providers. A review of the data supporting interchangeability (substitution with vaccines containing fewer antigens) and mixed schedules from the same manufacturer

ABSTRACTIntroduction: Combination vaccines improve vaccine uptake and open the infant immunization space for additional vaccines. Hexavalent vaccines have been marketed since 2000. Infanrix hexa (combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b conjugate vaccine, DTPa-HBV-IPV/Hib, GSK) is longest on the market, providing 16 years post-marketing experience. Each DTPa-HBV-IPV/Hib vaccine component is licensed alone and/or in smaller combination vaccines. Programmatic considerations sometimes require an interchange between vaccines due to unavailability, program change or mixed schedules (when the number of required antigens differs across scheduled primary vaccination visits).Areas covered: Immunogenicity and safety data from 11 GSK-sponsored clinical trials support the interchangeability of DTPa-HBV-IPV/Hib within the same vaccines family, and use of DTPa-HBV-IPV/Hib in mixed primary vaccination schedules.Expert commentary: Data show acceptabi...