Well-defined synthetic peptides are attractive for vaccine development. However, they are usually poorly immunogenic and sensitive to proteolytic degradation, thus require conjugation to carrier proteins and/or addition of adjuvants. Lactic acid bacteria (LAB) have become promising vehicle for mucosal vaccines due to their safety profile and natural adjuvanticity. The choice of carrier and mode of presentation hugely affect the stability and immunogenicity of the antigen, thus determine effectiveness of the resulting vaccines. We propose that the group A streptococcus (GAS) pilus structure expressed on the surface of Lactococcus lactis can be an ideal carrier for antigenic peptides, and established a novel mucosal vaccine platform termed PilVax1. Pili (sing. pilus) are hair-like bacterial cell surface protrusions important for host cell adhesion. The GAS pili consist of covalently linked pilins that are structurally stable and highly immunogenic. We identified several regions within the backbone pilin that can be replaced with antigenic peptides. Expressing the peptides within the pilus structure allows for peptide amplification, stabilisation and enhanced immunogenicity. Intranasal immunisation of mice with the resulting recombinant L. lactis strain produced strong peptide-specific antibody responses in serum and bronchoalveolar fluid. A recently developed tuberculosis vaccine based on a dominant T-cell epitope generated both humoral and cellular immune responses in the immunised mice2. PilVax vaccination resulted in peptide-specific CD4+ T cells at levels similar to those resulting from BCG immunisation, as well as an unexpected increase in the numbers of CD3+CD4-CD8- (double negative [DN]) T cells in the lungs of vaccinated animals. These cells types were shown to be responsible for the cytokine production following stimulation with the cognate peptide. This presentation will also give an overview of other PilVax projects focusing on various infectious diseases, including gonorrhoea and influenza. Results from these ongoing studies demonstrate the suitability of developing PilVax into useful mucosal vaccines.