Interchangeability of Hexaxim and Infanrix Vaccines
Hexaxim (hexavalent vaccine) and Infanrix (DTaP vaccine) cannot be used interchangeably as they contain different antigens and are designed for different vaccination purposes. 1
Vaccine Composition and Indications
Infanrix (DTaP)
- Infanrix is a DTaP (diphtheria, tetanus, acellular pertussis) vaccine licensed for active vaccination against diphtheria, tetanus, and pertussis as a 5-dose series in infants and children aged 6 weeks through 6 years 1
- Contains diphtheria and tetanus toxoids plus three pertussis antigens (pertussis toxin, filamentous hemagglutinin, and pertactin) 1
- Designed to be part of the routine childhood immunization schedule as a standalone DTaP vaccine or in combination products 1
Hexaxim (Hexavalent)
- Hexaxim is a fully liquid, hexavalent combination vaccine that provides immunization against six diseases: diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, and invasive diseases caused by Haemophilus influenzae type b 2, 3
- Approved for primary and booster vaccination in infants 6 weeks and older 2
- Contains additional antigens beyond those in Infanrix, making it a more comprehensive but different vaccine product 3
Guidelines on Vaccine Interchangeability
General Principles
- The Advisory Committee on Immunization Practices (ACIP) recommends that whenever feasible, the same brand of DTaP vaccine should be used for all doses of the vaccination series 1
- However, if the vaccine provider does not know or does not have available the type of DTaP vaccine previously administered, this should not present a barrier to vaccination 1
- In such cases, any of the licensed DTaP vaccines may be used to complete the vaccination series 1
Specific Guidance
- There are limited data regarding the safety, immunogenicity, and efficacy of using DTaP vaccines from different manufacturers for successive doses 1
- The ACIP states: "Data do not exist regarding the safety, immunogenicity, and efficacy of using DTaP vaccines from different manufacturers for successive doses of the primary or booster vaccination series" 1
- For hexavalent vaccines specifically, studies show Hexaxim can be given as a booster for infants primed with Infanrix Hexa (a different hexavalent vaccine), but not with Infanrix DTaP alone 2
Clinical Considerations
Safety and Efficacy
- Both vaccines have demonstrated good safety profiles in their respective clinical trials 2, 4
- Switching between different vaccine products or manufacturers may have unknown effects on overall immunity and protection 1
- Hexaxim has been shown to be non-inferior to other licensed hexavalent vaccines in terms of immunogenicity 2
Practical Implications
- Using the correct vaccine for the intended purpose is crucial for ensuring proper immunization coverage 1
- Infanrix (DTaP) does not provide protection against hepatitis B, polio, or Haemophilus influenzae type b, which are covered by Hexaxim 1, 2
- Combination vaccines like Hexaxim reduce the number of injections needed, potentially improving vaccination compliance 3
Common Pitfalls to Avoid
- Do not substitute a hexavalent vaccine (Hexaxim) for a trivalent vaccine (Infanrix) as this would result in missing protection against three diseases 2, 4
- Do not assume that all DTaP-containing vaccines are interchangeable without reviewing their specific components 1
- When switching between vaccine brands is unavoidable, ensure that all required antigens for the child's age and vaccination schedule are provided 1
- Always verify the specific licensed indications for each vaccine product, as they may vary in terms of approved age ranges and dosing schedules 1