DEVELOPMENT OF A CONTROLLED RELEASE DELIVERY SYSTEM FOR IMMUNOGENS

IN MANY INSTANCES, THE EFFECTIVENESS OF A VACCINE LARGELY DEPENDS ON MULTIPLE INOCULATIONS. IN ORDER TO ACHIEVE A HIGH DEGREE OF PROTECTIVE IMMUNITY, "BOOSTER" IMMUNIZATIONS ARE OFTEN REQUIRED. IMMUNIZATION OF LARGE NUMBERS OF PEOPLE, THEREFORE, PRESENTS A LOGISTICS PROBLEM. THE PROPOSED DELIVERY SYSTEM EMPLOYS THE USE OF POLY(LACTIC/GLYCOLIC) ACID (PLGA). VACCINE PREPARATIONS COULD BE INCORPORATED IN THE PLGA COPOLYMER AS MICROPARTICLES AND ADMINISTERED INTRAMUSCULARLY FOR IMMUNIZATION AGAINST A NUMBER OF PARASITIC, VIRAL, AND BACTERIAL INFECTIONS. IN THIS NOVEL SYSTEM, SOME OF THE MICROPARTICLES WOULD IMMEDIATELY RELEASE VACCINE OVER A PERIOD OF THREE TO SEVEN DAYS; OTHER MICROPARTICLES PRESENT IN THE INITIAL INJECTION WOULD HAVE A DELAYED RELEASE CHARACTERISTIC (TWO TO FOUR WEEKS), AND WOULD FINALLY RELEASE THEIR BOUND VACCINE MATERIAL ALSO OVER THREE TO SEVEN DAY PERIOD, SIMULATING A SECOND VACCINE INJECTION. THE PRIMARY GOAL OF PHASE I WILL BE TO DEVELOP A MODEL PROTEIN FORMULATION WHICH RELEASES THE PROTEIN IN AN UNALTERED STATE, WITH AN OPTIMAL RELEASE PATTERN FOR STIMULATING IMMUNOGENICITY, AND WHICH HAS AN OPTIMAL ADJUVANT EFFECT.