Here a transcomplemented strain of a non-pathogenic L. inn strain expressing genes of the vgc cluster provides robust protection with a single dose of 10 7 cfu bacteria without causing any signs of overt illness. The LD50 of the wild type Lm is around 5000 cfu. As shown in figure 1A , the L.inn::vgc strain does not grow in-vivo beyond day 3 post-infection and is subsequently eliminated. These properties, imparting protective responses and rapid elimination from the host are considered to be desirable properties for successful vaccine vectors. Our results, namely, the in vivo survival pattern, the induction of interferon's and antigen specific CD8 + T cells, the lack of overt detrimental inflammatory reactions and most importantly the induction of protection against challenge with Listeria, allow the conclusion that the L.inn::vgc strain is potentially capable of inducing protection and that further development of this strain as a suitable live bacterial vaccine vector in clinical settings are warranted.