Author
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AUDIBERT, F - VACSYN S.A., FRANCE |
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CHEDID, L - VACSYN S.A., FRANCE |
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Brogden, Kim |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 8/15/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: New generation subunit vaccines are safer than traditional vaccines containing killed or attenuated microorganisms. However, they lack the capacity of evoking appropriate protective responses. They are less immunogenic and in most cases do not trigger all the different components of an effective immune response. Therefore suitable adjuvants and delivery systems are required to develop safe and efficient new vaccines. Immunoadjuvants which are often bacterial components or their analogs can activate cells inducing the synthesis and release of cytokines. Various emulsions, which favor the uptake of antigens by specialized presenting cells, have been already extensively used in the veterinary field and different delivery systems such as biodegradable microspheres are under evaluation for clinical use. Besides their carrier activity, delivery systems may act by allowing a slow release of the vaccine antigens and their phagocytosis followed by the release of cytokines. The capsular polysaccharide of Pasteurella haemolytica serotype A1 is a poor immunogen for the prevention of pneumonic pasteurellosis of ruminants. The use of an immunoadjuvant combination comprising a muramyl dipeptide derivative in an oily emulsion has allowed us to prepare an effective subunit vaccine devoid of side effects. This preparation tested in sheep and calves has induced an early production of bactericidal antibodies 7 days after the primary immunization followed by a high and persistent raise of protective antibodies.5 |
