LOCAL AND SYSTEMIC IMMUNE-RESPONSE TO A MICROENCAPSULATED SUBUNIT VACCINE FOR PLAGUE

Microencapsulated F1 and V sub-unit antigens of Yersinia pestis were u sed to immunize mice intraperitoneally with a combination of 25 mu g o f each of the microencapsulated sub-units. The combined microsphere fo rmulation induced both mucosal and systemic immunity. There was an add itive effect in combining sub-units and the protection afforded by the combined microencapsulated antigens was superior to that provided by the administration of any single encapsulated antigen and by the exist ing whole cell vaccine. The protective efficacy of the combined microe ncapsulated sub-units was further enhanced by co-administering cholera toxin B sub-unit. Microencapsulation of the sub-units offered advanta ges which included depot release of the vaccine in vivo and the facili tation of oral, intranasal or inhalational delivery. Therefore, immuni zation with microencapsulated sub-unit antigens was an effective means of generating humoral and cellular responses which endowed protective immunity.