Floss-based vaccination targets the gingival sulcus for mucosal and systemic immunization.

The oral cavity is an accessible site for vaccination, but its sublingual and buccal sites have limited vaccine uptake. Here we show that flat tape dental floss can deliver vaccines through the junctional epithelium of the gingival sulcus, exploiting its naturally leaky properties. Floss-based vaccination delivered protein, inactivated virus, peptide-presenting immunogenic nanoparticles and messenger RNA. In mice, gold nanoparticles functionalized with a peptide derived from the ectodomain of the transmembrane matrix 2 protein of human influenza virus stimulated local lymph nodes, increased CD4