"Protected" Nanoparticles for an Oral Single-Dose Staphylocaccal Enterotoxin B Vaccine

Conventional methods of immunization in general require multiple injections at certain intervals to achieve the required protective immune response. However, this immunization protocol may not always be practical, especially for Army personnel in the field or in remote areas where access to the health care personnel may be difficult. Our program is based on the concept of complete immunization (prime and boosting) with a single oral vaccine dosage form using a time-release capsule - "protected" biodegradable nanoparticles (polyactic-polyglycolic acid) containing staphylococcal enterotoxin B (SEB)-toxoid as a model protein-based antigen. thus, the nanoparticles will be enclosed in a protective time-release capsule known as the PORT System. The capsule is deigned to protect nanoparticles and the encapsulated antigen from both gastric enzymes and acidic pH, and to release the enclosed antigen loaded nanoparticles in a burst in the ileum for optimal uptake by the gut-associated lymphoid tissue to induce an immune response. No other group has investigated this concept of capsule "protected" nanoparticles. Our working hypothesis is that by virtue of our smaller particle size (nanoparticles Vs. previous microparticles), and enteric protection using the PORT System, our oral vaccination approach will prove significantly better than those studied previously. Our goal in the Phase I-SBIR program is to test the feasibility of this concept of oral immunization using SEB-toxoid to achieve an immune response comparable to that of the conventional method of subcutaneous immunization. The long-term objective of our program in the Phase II-SBIR is to further develop our nanoparticle-vaccine system in a time-release capsule for a singel-dose oral SEB vaccine adminsitration in a clinical trial. Nanoparticle-vaccine development will involve the formulation in Phase II-SBIR of various staged booster doses can e simply given orally in a single contact encounter. Ultimately this system may be useful for a combination of vaccines to achieve a long-term protective immune response against vaccine-preventable diseases. Such a system will have importance to US Armed forces in the field,