Develop a safe, effective, and otherwise attractive vaccine against dental caries for human use. Establish in a rat model the most effective caries-prevention combination of antigen, adjuvant, and dosing regimen using the gastric route of immunization. Crude S. mutans preparations and then purified S. mutans antigens will be tested with selected particulate adjuvants for effects on plasma and salivary immunoglobulins, oral S. mutans levels, and caries.