Vaccine Adjuvant Technology
Consisting of polymer nanospheres using proprietary and patented PNS technology for HIV, influenza and anthrax vaccines
Vaccination is the most cost-effective tool for the control and prevention of infectious diseases. However, multiple inoculations are often required to achieve desirable protection even with potent antigens.
In order to increase the therapeutic efficiency of such vaccines, adjuvants are used with vaccines to augment the immune response. There are several types of adjuvants with different modes of action. Adjuvants form a depot of antigen at the site of inoculation with slow release of antigens. Adjuvants can improve the performance of vaccines by targeting the antigen to antigen-presenting cells, eliciting specific cytokines that direct Th1 or Th2 immune responses. Most of the adjuvants increase the production of specific antibodies. Adjuvants that enhance cell-mediated immunity for vaccines against bioterrorist agents are desirable since many of these agents are intracellular pathogens.
Several vaccines are under development and testing for HIV, influenza and bioterrorism agents. Most of these vaccines are recombinant or purified subunit vaccines. These subunit vaccines are being developed because they are safer than whole-cell vaccines. However, these subunit vaccines often result in weaker immune responses. The use of adjuvants capable of enhancing and directing the immune response to subunit vaccines is a critical component of a rational vaccine design.
Current Vaccine Adjuvant Technology
Presently in the United States, aluminum salt- or gel-based adjuvants are the predominant adjuvants used in licensed vaccines. In 2009, the FDA approved, for the first time, a vaccine that includes monophosphoryl lipid A (MPL) as an adjuvant in addition to the aluminum hydroxide adjuvant (FDA newsletter, July 7, 2011).
However, concerns have been raised recently about long-term toxicity from aluminum with potential for autoimmunity and long-term brain inflammation with the associated neurological complications (Tomljenovic and Shaw, 2011).
Biodegradable Polymer Microspheres as Novel Vaccine Adjuvants
Microspheres, comprised of biodegradable hydrophobic copolymers, appear to have an adjuvant effect on microencapsulated anthrax rPA, possibly caused by its controlled release and/or immune stimulation of the dendritic cells by the copolymer (Flick-Smith et al., 2002).
While highly promising, the hydrophobic microspheres are manufactured from organic solvents. There are certain problems associated with the use of conventional organic phase solvents in polymer microencapsulation.
Manufacturing Problems with Current Polymer Microspheres Technologies
Aphios' Vaccine Adjuvant Technology
Advantages and Benefits
We are seeking strategic corporate partners as well as partnerships with government and research institutions interested in developing a stable, effective anthrax vaccine adjuvant for anthrax vaccination.