Carrier priming or suppression: understanding carrier priming enhancement of anti-polysaccharide antibody response to conjugate vaccines.
BACKGROUND
With the availability of newer conjugate vaccines, immunization schedules have become increasingly complex due to the potential for unpredictable immunologic interference such as 'carrier priming' and 'carrier induced epitopic suppression'. Carrier priming refers to an augmented antibody response to a carbohydrate portion of a glycoconjugate vaccine in an individual previously primed with the carrier protein. This review aims to provide a critical evaluation of the available data on carrier priming (and suppression) and conceptualize ways by which this phenomenon can be utilized to strengthen vaccination schedules.


METHODS
We conducted this literature review by searching well-known databases to date to identify relevant studies, then extracted and synthesized the data on carrier priming of widely used conjugate polysaccharide vaccines, such as, pneumococcal conjugate vaccine (PCV), meningococcal conjugate vaccine (MenCV) and Haemophilus influenzae type b conjugate vaccines (HibV).


RESULTS
We found evidence of carrier priming with some conjugate vaccines, particularly HibV and PCV, in both animal and human models but controversy surrounds MenCV. This has implications for the immunogenicity of conjugate polysaccharide vaccines following the administration of tetanus-toxoid or diphtheria-toxoid containing vaccine (such as DTP).


CONCLUSIONS
Available evidence supports a promising role for carrier priming in terms of maximizing the immunogenicity of conjugate vaccines and enhancing immunization schedule by making it more efficient and cost effective.
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, New South Wales, Australia.
Karl
K
Pobre
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, New South Wales, Australia; Sydney Medical School, The University of Sydney, New South Wales, Australia. Electronic address: Mohamed.tashani@health.nsw.gov.au.
Mohamed
M
Tashani
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, New South Wales, Australia; Sydney Medical School, The University of Sydney, New South Wales, Australia.
Iman
I
Ridda
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, New South Wales, Australia.
Harunor
H
Rashid
Department of Immunology, Children's Hospital at Westmead, Westmead, New South Wales, Australia.
Melanie
M
Wong
National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, New South Wales, Australia; Sydney Emerging Infections and Biosecurity Institute, University of Sydney, Australia.
Robert
R
Booy
D000818:Animals; D000917:Antibody Formation; D016667:Bacterial Capsules / Q000276:immunology; D004337:Drug Carriers / Q000494:pharmacology*; D018073:Haemophilus Vaccines / Q000276:immunology; D006801:Humans; D007115:Immunization Schedule; D022401:Meningococcal Vaccines / Q000276:immunology; D022242:Pneumococcal Vaccines / Q000276:immunology; D011134:Polysaccharides / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000276:immunology*
D004337:Drug Carriers; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D022401:Meningococcal Vaccines; D022242:Pneumococcal Vaccines; D011134:Polysaccharides; D018074:Vaccines, Conjugate
Antibody response; Carrier priming; Conjugate vaccine; Polysaccharide vaccine