Dental Floss Tested as a New Route for Vaccine Administration

• by Rishma Parpia

• Published July 28, 2025
• Vaccines

  In a 2025 study published in Nature Biomedical Engineering, researchers reported that applying floss laced with vaccine components such as proteins and inactive viruses along the gum lines of mice triggered an immune response.¹ The goal is to use dental floss to vaccinate large numbers of people during a pandemic. The researchers found that “Floss-based vaccination delivered protein, inactivated virus, peptide-presenting immunogenetic nanoparticles and messenger RNA” into the body, and “induced strong and sustained immune activation across multiple organs, robust systemic and mucosal antibody responses and durable protection…”

  The new way of administering vaccines by coating dental floss with vaccine components targets a specific area along the gum line called the junctional epithelium (JE), which is highly absorbent and rich in immune cells. Since this area is hard to access, scientists proposed using dental floss, a tool that already reaches the JE during regular dental care both in dentist offices and for use at home. They tested the approach on mice by applying vaccine-coated floss to teeth of the mice and found that the vaccine reached the gum tissue. The mice’s immune systems responded as effectively as they would to a traditional vaccine.²

  Rohan Ingrole, PhD, lead researcher of the study and a chemical engineer at Texas Tech University said:

  The floss-based vaccination induced both systemic and mucosal immunity, while conventional intramuscular shots largely stimulate systemic immunity. Mucosal immunity is important because most of the pathogens enter through the mucosal routes.³

  The dental floss was used to deliver different types of vaccines, including proteins, inactive influenza virus, peptide-based vaccines, and even mRNA, all of which triggered strong inflammatory responses in both the organs in the body and on mucosal surfaces in the gut and reproductive tract. In comparison to existing oral vaccine methods, the researchers reported the floss performed significantly better. The researchers claimed that dental floss vaccines also avoid the risks associated with nasal vaccines, which can sometimes carry ingredients into the brain.⁴

  To explore whether this method could work in humans, the researchers conducted a small study involving 27 healthy volunteers who used dental floss picks coated with a food-safe dye. On

  average, the dye successfully reached the target gum tissue, specifically the JE, about 59 percent of the time. While the results showed promise, the researchers noted some variability, likely due to floss design limitations. They believe that improving the shape and structure of the floss picks could increase delivery accuracy and consistency.⁵

  Researchers Highlight Pandemic Use for Floss-Based Vaccines

  The researchers highlight advantages of floss-based vaccination, including the elimination of needles and cold storage, making it easier to use in underdeveloped regions with limited health care resources. They noted that is also pain-free and could serve as an accessible method of vaccine distribution during a pandemic.

  However, they also noted some limitations. The approach cannot be used in infants who do not yet have teeth, and gum infections may reduce its effectiveness. Further research is needed to address these challenges and better understand any potential adverse effects.⁶

  Harvinder Gill, PhD, a researcher on the study and a bioengineer at North Carolina State University said, “The next step is to translate the research to larger animals, which can then lay the foundation for human testing in the near future.”⁷

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