Gene gun intradermal DNA immunization followed by boosting with modified vaccinia virus Ankara: enhanced CD8+T cell immunogenicity and protective efficacy in the influenza and malaria models

In influenza and malaria, CD8+ T cells play an important role in protective immunity in mice. An immunization strategy consisting of DNA priming follo wed by boosting with recombinant modified vaccinia virus Ankara (MVA) induc es complete protection, associated with high levels of CD8+ T cells, agains t Plasmodium berghei sporozoite challenge in mice. Intradermal delivery of DNA with a gene gun requires smaller amounts of DNA than intramuscular inje ction, in order to induce similar levels of immune responses. The present s tudy compares both routes for the induction of specific CD8+ T cell respons es and protection using different prime-boost immunization regimes in the i nfluenza and the malaria models. In the DNA/MVA regime, equally high CD8+ T cell responses and levels of protection are achieved using ten times less DNA when delivered with a gene gun compared to intramuscular injection. (C) 1999 Elsevier Science Ltd. All rights reserved.