Is There an Optimal Formulation and Delivery Strategy for Subunit Vaccines?

Abstract

Modern vaccine design has moved away from attenuated or inactivated whole-pathogen vaccines to more pure and defined subunit vaccines. However subunit antigens have poor bioavailability and stability and lack immunogenicity. To overcome these issues subunit vaccines have to be administered in a suitable delivery system in combination with immune stimulants. Many different delivery systems have been developed and investigated each having different modes of action, for example increasing delivery and/or sustaining delivery of antigen to immune cells. In addition a number of different routes of immunization are possible and these can play a crucial role in determining the fate of an immune response. In this review the different strategies for the delivery of prophylactic and therapeutic subunit vaccines along with the impact of these on the immune responses generated are discussed.

Native‐like Env trimers as a platform for HIV‐1 vaccine design

“…Newer, icosahedral nanoparticle designs might also be valuable (185,186). Other biodegradable nanoparticle approaches to Env trimer presentation could include chitosan- or poly(D,L-lactic-co-glycolic acid (PLGA))-based particles and ones based on “bacterial ghosts” (187–190). …”

“…Most of the above particulate antigen presentation systems have the additional potential for including immunostimulatory molecules such as TLR activators on their surfaces or within their internal spaces, with the goal of further stimulating desirable immune responses (63,177,185,186,188,190). In principle, such an adaptation could allow the targeted delivery of an adjuvant component directly to the site where an immune response to the trimer component is initiated.…”

Technological Microbiology: Development and Applications

“…These antigens are purified from microorganisms, produced by recombinant DNA techniques, or chemically synthesized. They are poorly reactogenic, which is an advantage in terms of adverse effects but a disadvantage in terms of stimulating potent and long-lasting immune responses (Bobbala and Hook, 2016). Thus, these vaccines often require the co-administration of efficient adjuvants to activate and modulate immune responses (Reed et al, 2009; Schmidt et al, 2016).…”

Synthetic Biodegradable Microparticle and Nanoparticle Vaccines against the Respiratory Syncytial Virus

“…Polymeric particles carriers can be made from a variety of polymers, such as chitosan, alginate, silica, polylactide, polyethylenimine, propylene sulfide, poly (lactic-co-glycolic acid) (PLGA), polymethylmethacrylate (PMMA), poly(ethylacrylic acid) and poly(butyl acrylic acid) (reviewed in [69]). PLGA and chitosan are the two most widely used for vaccine delivery, and these two polymers have been recently evaluated on macrophages [70].…”