Vaxfectin: a versatile adjuvant for plasmid DNA- and protein-based vaccines

Importance of the field: Many vaccines require the use of an adjuvant to achieve immunity. So far, few adjuvants have advanced successfully through clinical trials to become part of licensed vaccines. Vaxfectin (R) (Vical, CA, USA) represents a next-generation adjuvant with promise as a platform technology, showing utility with both plasmid DNA (pDNA) and protein-based vaccines. Areas covered in this review: This review describes the chemical, physical, preclinical and clinical development of Vaxfectin for pDNA-based vaccines. Also included is the preclinical development of Vaxfectin-adjuvanted protein-and peptide-based vaccines. What the reader will gain: The reader will gain knowledge of vaccine adjuvant development from bench to bedside. Take home message: Vaxfectin has effectively boosted the immune response against a range of pDNA-expressed pathogenic antigens in preclinical models extending from rodents to non-human primates. In the clinic, Vaxfectin-adjuvanted pDNA-based H5N1 influenza vaccines have been shown to be well tolerated and to result in durable immune responses within the predicted protective range reported for protein-based vaccines.