Novel adjuvants and delivery systems for enhancing immune responses induced by immunogens

Abstract

Vaccines are the most important preventive measure against infectious diseases. In developing an effective vaccine, besides the primary challenge of identifying the most relevant immunogen and efficient regime of immunization, selection of a potent adjuvant and delivery method is equally critical. The formulation of immunogens with different adjuvants may affect the affinity maturation of antibody responses differently, suggesting that the structure of specific epitopes within the immunogen may be influenced by different adjuvants. Thus, developing adjuvants that can efficiently activate both the innate and adaptive arms of the immune system is a major challenge for vaccine researchers. The use of novel adjuvants in combination with novel immunogen design holds great promise towards the goal of enhancing the potency, breadth and durability of vaccines. This article summarizes the different immunopotentiators (and immunomodulators) as well as the delivery systems that are available for vaccine generation and the types of immune responses that each of them induces. Also discussed are adjuvants that have a combination of both immunomodulatory and delivery properties.

Keywords::

• adjuvant
• immunogen
• MF59
• MPL
• nanoemulsions
• PAMPs
• PLG microparticles
• PRR
• SMIP

Acknowledgements

The authors would like to thank Rino Rappuoli, Vice President and Global Head of Vaccines Research (Novartis Vaccines) and Christian Mandl, Vice President and Head, US Vaccines Research (Novartis Vaccines) for their support and encouragement; and other members of Vaccines Research, particularly Mano Singh, Derek O’Hagan, Susan Barnett and Jeffrey Ulmer for their valuable contributions to the vaccine field.

Financial & competing interests disclosure

Some of the work reported in this article was supported by grants and contracts (AI-95367, I-AI-05397 and 5PO1-AI 48225-03) from the National Institute of Allergy and Infectious Diseases, NIH (Bethesda, MD, USA). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.