Day: July 31, 2025

A new vaccine administration method doesn’t rely on needles or sprays to deliver the vaccine, but on dental floss. 

Publishing their findings in Nature Biomedical Engineering, a research team tested the vaccine-coated dental floss on animals, introducing the vaccine through the gums and other tissue in the mouth. The study results indicated that this helped produce antibodies in the mucosal surfaces of the lungs and nose. 

“[It] would be easy to administer, and it addresses concerns many people have about being vaccinated with needles,” said Harvinder Singh Gill, corresponding author of a paper on the work in a press release. “And we think this technique should be comparable in price to other vaccine delivery techniques."

Introducing Vaccines to the Body

For this study, the researchers knew they needed to focus on junctional epithelium. This refers to the tissues that line our organs and other body parts, such as the stomach, lungs, and intestines. Most of these epithelia are designed to keep foreign invaders, like viruses, bacteria, and even dirt, from entering the bloodstream. However, that’s not the case for junctional epithelium.

The deep tissues between your tooth and gums lack the same protection that other epithelia have. Because of this, junctional epithelium can release immune cells that fight bacteria.

“Because the junctional epithelium is more permeable than other epithelial tissues — and is a mucosal layer — it presents a unique opportunity for introducing vaccines to the body in a way that will stimulate enhanced antibody production across the body’s mucosal layers,” said Gill in the press release.

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Testing Vaccinated Dental Floss 

In the lab, researchers added a peptide flu vaccine to unwaxed dental floss and used it to floss mice’s teeth. They compared the antibody production in mice that received the vaccine via nasal spray and drops under the tongue. 

“We found that applying vaccine via the junctional epithelium produces far superior antibody response on mucosal surfaces than the current gold standard for vaccinating via the oral cavity, which involves placing vaccine under the tongue,” said Rohan Ingrole, first author of the paper and Ph.D. student under Gill at Texas Tech University, in a press release. “The flossing technique also provides comparable protection against flu virus as compared to the vaccine being given via the nasal epithelium.”

Delivering a vaccine in this manner could be revolutionary, potentially improving vaccine safety. 

“This is extremely promising, because most vaccine formulations cannot be given via the nasal epithelium — the barrier features in that mucosal surface prevent efficient uptake of the vaccine,” Gill said in a press release. “Intranasal delivery also has the potential to cause the vaccine to reach the brain, which can pose safety concerns. However, vaccination via the junctional epithelium offers no such risk.”

Delivery via Floss Pick 

Though the dental floss method proved effective, the research team knew that asking patients to hold vaccine-coated floss wasn’t practical. Instead, the team shifted towards floss picks — small, pronged applicators with a short piece of floss strung between the prongs. 

To test the effectiveness of the floss pick, the team added a fluorescent dye to it and asked 27 study participants to administer the vaccine to the junctional epithelium between the gums. 

“We found that approximately 60 percent of the dye was deposited in the gum pocket, which suggests that floss picks may be a practical vaccine delivery method to the epithelial junction,” Ingrole said in a press release. 

Gill and the research team believe that these results could soon lead to the method being moved into clinical trials, although many questions remain unanswered. Overall though, the team thinks this could be an improved vaccine delivery method. 

"In addition, we would need to know more about how or whether this approach would work for people who have gum disease or other oral infections,” Gill said in the press release.

There’s still more to learn about this method, but it could change the way we see vaccines and dental floss.

This article is not offering medical advice and should be used for informational purposes only

Read More: Vaccines, Not Supplements, Remain the Best Way to Fight Measles

Article Sources

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A graduate of UW-Whitewater, Monica Cull wrote for several organizations, including one that focused on bees and the natural world, before coming to Discover Magazine. Her current work also appears on her travel blog and Common State Magazine. Her love of science came from watching PBS shows as a kid with her mom and spending too much time binging Doctor Who.