Bioerodible Polymeric Microcapsules for Vaccine Delivery

Immunization has proven to be an effective method of protecting both military and cibilian populations from disease caused by bacterial, viral, or toxic agents. The U.S. military faces the problem of protecting its personnel from incapacitation caused by exposure to agents of both natural and man-made orgin. In developing countries, immunization is the most cost-effective weapon for disease prevention. Unfortunately, since many vaccination protocols require multiple injections over an extended period of time, many of the potential benefits of widespread vaccination programs are not being realized due to logistical problems, expense, and high drop-out rates. One approach to alleviating these problems is the development of bioerodible polymeric vaccine-containing microcapsules capable of prolonged delivery of antigen and the ability to confer complete immunity for an extended period of time. We propose to develop a microencapsulation system in which vaccines and other proteins can be encapsulated out of aqueous solution, producing biocompatible bioerodible capsules capable of prolonged antigen release. We will evaluate the efficacy of this vaccine encapsulation and delivery system using a vaccine against a naturally occurring toxic agent of great interest to both military and civilian health agencies.