Recent Advances in Subunit Vaccine Carriers

Abstract

The lower immunogenicity of synthetic subunit antigens, compared to live attenuated vaccines, is being addressed with improved vaccine carriers. Recent reports indicate that the physio-chemical properties of these carriers can be altered to achieve optimal antigen presentation, endosomal escape, particle bio-distribution, and cellular trafficking. The carriers can be modified with various antigens and ligands for dendritic cells targeting. They can also be modified with adjuvants, either covalently or entrapped in the matrix, to improve cellular and humoral immune responses against the antigen. As a result, these multi-functional carrier systems are being explored for use in active immunotherapy against cancer and infectious diseases. Advancing technology, improved analytical methods, and use of computational methodology have also contributed to the development of subunit vaccine carriers. This review details recent breakthroughs in the design of nano-particulate vaccine carriers, including liposomes, polymeric nanoparticles, and inorganic nanoparticles.

Nanoparticle-Based Vaccines Against Respiratory Viruses

“…Nevertheless, live-attenuated vaccines against influenza virus suffer from safety concerns due to their nature and represent a risk for elderly and immunosuppressed humans (21). Besides, killed pathogen vaccines and virus-derived subunit vaccines induce weaker immune responses and often require the use of an adjuvant to boost efficiency (22).…”

Synthesis and characterization of physicochemical and immunological properties of recombinant NS3-G2 dendrimer conjugate

“…Several studies have shown that NS3 protein is a promising antigen for the purpose of anti-HCV vaccine development [26,27]. However, subunit vaccines induce a lower immune response compared to whole cell vaccines, requiring improved vaccine carriers/adjuvants [28]. Dendrimer nanoparticles with a uniform small size (about 90 nm) and many functional groups on the surface have been proposed as suitable carriers/adjuvants for presentation of subunit antigens [28].…”

“…However, subunit vaccines induce a lower immune response compared to whole cell vaccines, requiring improved vaccine carriers/adjuvants [28]. Dendrimer nanoparticles with a uniform small size (about 90 nm) and many functional groups on the surface have been proposed as suitable carriers/adjuvants for presentation of subunit antigens [28]. The adjuvant effect of nanoparticles may include prolonged presentation, enhanced antigen uptake and direct stimulation of the innate immune system [29].…”

Nanomaterials for cancer immunotherapy

“…Whole-cell antigens contain broad epitopes for fully preserved tumor antigens but are often poorly defined, differ from one person to another, and are difficult to manufacture [61, 62]. Subunit antigens contain fewer but more defined antigens, including oncoproteins, peptides, DNA, mRNA, polysaccharides, etc.…”