Vaccination by non-parenteral routes: characteristics of immune response

Antibody and cell-mediated immune response in systemic and external mucosal sites was studied after natural or vaccine induced infections with rubella and mumps viruses. Natural rubella infection or immunization with RA27/3 rubella vaccine by intranasal and frequently by the subcutaneous route resulted in regular appearance of antibody response in the serum and respiratory tract and cellular immunity in circulating lymphocytes and tonsillar lymphoid tissue. Subcutaneous immunization with HPV-77 and Cendehill rubella vaccine resulted in antibody response in the serum with little or no response in the respiratory tract. A minimal cell-mediated immune response in systemic or respiratory lymphoid tissue was observed after such immunization. Intranasal immunization with HPV-77 frequently elicited a transient antibody and cell-mediated activity in the respiratory tract with no response in the serum and peripheral lymphocytes. Studies carried out with natural mumps infection or subcutaneous immunization with live attenuated mumps vaccine suggested that either route of infection may result in the development of antibody and cell-mediated immune responses in systemic sites as well as in the respiratory tract. These observations suggest that the immunologic outcome of immunization by non-parenteral route may be determined by the types of viral antigen employed, the nature of locally available immuno-competent tissue, the ability of mucosal site to capture an antigen or accept replication of live virus vaccines, and the degree of prior sensitization with the same antigen.