Strategies for exploiting the immune system in the design of vaccines.
There are three types of vaccines in medical use today--live, attenuated agents, mainly viruses; inactivated whole organisms; and subunit preparations. Though there are examples in each category of successful preparations, live attenuated viruses have almost invariably given long-lasting immunity after one or two administrations. Contributing reasons for this are gleaned, not from human vaccine studies, but from model systems and it is concluded that a vaccine needs to achieve four goals: activation of antigen-presenting cells; overcoming genetic variability in T cell responses; generation of high levels of T and B memory cells; and persistence of antigen for recruitment of B memory cells. Of the newer approaches to vaccine development, synthetic peptides have substantial limitations but should be successful in some cases. Subunit preparations may also be limited as a general method. Some live viral or bacterial vaccines, used as vectors of nucleic acid coding for other antigens, hold considerable promise as is illustrated by recent examples.
Ada
G
G
Department of Immunology and Infectious Diseases, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205.
D000818:Animals; D000941:Antigens / Q000276:immunology / Q000493:pharmacokinetics; D001402:B-Lymphocytes / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes; D006801:Humans; D007156:Immunologic Memory; D007239:Infections / Q000276:immunology; D051379:Mice; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology; D014612:Vaccines / Q000276:immunology*
D000941:Antigens; D000939:Epitopes; D014612:Vaccines