Biodegradable Vaccine Microcapsules for Systemic and Mucosal Immunization against VEE.
Final rept. 30 Aug 90-29 Aug 95,
ALABAMA UNIV IN BIRMINGHAM
Pagination or Media Count:
The overall goal of this contract effort was to determine the effectiveness of microencapsulated vaccines compared to the conventional vaccines in inducing protective immune responses against challenge with the pathogens Venezuelan equine encephalitis VEE virus and Bacillus anthracis. The microsphere vaccines were formulated of the biodegradable and biocompatible co-polymer polyDL-lactide-co-glycolide DL-PLG. Formalin-fixed andor 60Co-inactivated TC-83 VEE virus or protective antigen PA of B. anthracis was encapsulated in DL-PLG by an emulsion-based process to yield microspheres of approximately 1 to 10 um in diameter and containing approximately 0.8 by weight antigen. Mice immunized by the systemic route with antigen encapsulated in microspheres composed of equal amounts of lactide and glycolide had higher protective immune responses than animals immunized with antigen alone. Vaccine prepared with formalin-fixed virus induced higher responses than untreated virus. Microencapsulated VEE prepared with the solvent methylene chloride compared to ethyl acetate induced higher levels of ELISA antibody activity, neutralization titers, and protection against systemic challenge. However, this relationship depended on the dose of vaccine. Similarly, microencapsulated PA induced higher responses than free antigen and induced the greatest protection against aerosol challenge when given to guinea pigs. Finally, mucosal, especially intratracheal, immunization with microencapsulated VEE induced systemic and mucosal responses and protection against aerosol challenge.
- *BACILLUS ANTHRACIS
- *VENEZUELAN EQUINE ENCEPHALOMYELITIS VIRUS
- PATHOGENIC MICROORGANISMS
- MUCOUS MEMBRANES
- GUINEA PIGS
- Medicine and Medical Research