protective immunity in mice following immunization with the cochleate-based subunit influenza vaccines

high morbidity and mortality of influenza virus infection makes it an important disease world-wide. mouse is a very well-studied animal model for this disease with similar manifestation to human disease. it would be desirable to induce mucosal as well as circulating immune responses to obtain protection from infection and to decrease the spread of the virus. cell mediated immunity (proliferative and cytolytic responses) is needed for long-term immunity. a new type of influenza subunit vaccine which can be given orally or parenterally has been developed to induce mucosal and circulating immune responses. this vaccine consists of membrane proteins rolled up in a unique phospholipid structures called protein cochleates. balb/c mice were immunized three times with influenza glycoprotein-containing cochleates orally or intramuscularly, or they were primed orally or intramuscularly followed by two boosts with the alternate routes. proliferation assays of spleen cells and elisa for iga, igg, and igm of the sera and saliva from these mice shown some differences in the immune responses induced by different immunization regimens. mucosal administration of the formulation led to secretory iga in saliva while parenteral immunization resulted in circulating igg. increased proliferative responses as well as igg following 2nd and 3rd administration, indicated the effect of boosting in all immunization regimens. oral immunization with influenza virus envelope glycoprotein-containing cochleates led to protection from infection in the lungs and trachea following intranasal challenge with the live virus.