Cationic liposomal vaccine adjuvants in animal challenge models: overview and current clinical status

Abstract

Cationic liposome formulations can function as efficient vaccine adjuvants. However, due to the highly diverse nature of lipids, cationic liposomes have different physical–chemical characteristics that influence their adjuvant mechanisms and their relevance for use in different vaccines. These characteristics can be further manipulated by incorporation of additional lipids or stabilizers, and inclusion of carefully selected immunostimulators is a feasible strategy when tailoring cationic liposomal adjuvants for specific disease targets. Thus, cationic liposomes present a plasticity, which makes them promising adjuvants for future vaccines. This versatility has also led to a vast amount of literature on different experimental liposomal formulations in combination with a wide range of immunostimulators. Here, we have compiled information about the animal challenge models and administration routes that have been used to study vaccine adjuvants based on cationic liposomes and provide an overview of the applicability, progress and clinical status of cationic liposomal vaccine adjuvants.

Keywords::

• adjuvants
• animal models
• cationic liposomes
• clinical trials
• vaccines

Acknowledgements

The authors wish to thank L El-Haj for excellent help with retrieval of references.

Financial & competing interests disclosure

The authors acknowledge funding from FastVac (2009-11-06). The authors are co-inventors of patents relating to cationic liposomes as vaccine adjuvants. All rights have been assigned to the Statens Serum Institut (Copenhagen, Denmark). All authors are employees at Statens Serum Institut. 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.