Since many children and about 10% adults have a fear of needles and cite this concern for avoiding vaccines, clinically known as trypanophobia, recent research has identified another immunization option.
Researchers have confirmed that the oral cavity is a convenient location for vaccination and is the target area for an innovative needle-free vaccine.
In a study published in late July 2025 in Nature Biomedical Engineering, the research team demonstrates that flat tape dental floss can effectively deliver vaccines through the junctional epithelium of the gingival sulcus, taking advantage of its naturally permeable properties.
Previously, floss-based vaccination has been used to deliver protein, inactivated viruses, peptide-presenting immunogenic nanoparticles, and messenger RNA.
In this study, mice with 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+T cells in lymph nodes, lungs, and spleen. It boosted antibody-secreting cells in the bone marrow.
Floss-based immunization induced strong and sustained immune activation across multiple organs, robust systemic and mucosal antibody responses, and durable protection against lethal influenza infection, independent of age, food, and liquid consumption.
Floss-based vaccination was found to be superior to sublingual and comparable with intranasal vaccination.
In human participants, fluorescent dye delivered via floss picks effectively reached the gingival sulcus, supporting clinical feasibility.
According to researchers, these findings establish floss-based vaccination as a simple, needle-free strategy that enhances vaccine delivery and immune activation compared with existing mucosal immunization methods.
As of August 14, 2025, no vaccine is available using the floss delivery option.