Flu Shot Season and Dental Floss Vaccination Research

As flu shot season approaches, there’s a lot of focus on finding new ways to deliver vaccinations that don’t involve needles. A recent study suggests an interesting alternative: dental floss. Researchers in the U.S. explored this method using lab mice and found that delivering vaccines via dental floss actually produced a better antibody response compared to injections under the tongue, and it performed similarly to nasal spray methods. If these findings translate to humans, it could mean some vaccines might be administered through tooth tape instead of needles.

The study highlights how flat tape dental floss can effectively deliver vaccines through the junctional epithelium, which is the tissue that connects gums to teeth. It turns out that this area has naturally leaky properties that could be beneficial. This junctional epithelium is part of a type of tissue called mucosal surfaces—these surfaces help shield organs and cavities in our body. Many viruses, including flu and Covid-19, can enter through these pathways.

Harvinder Singh Gill, a co-author and professor of Nanomedicine at North Carolina State University, noted that when vaccines are injected, antibody production mostly happens in the bloodstream, leading to fewer antibodies on mucosal surfaces. On the flip side, delivering vaccines through mucosal surfaces stimulates antibody production both there and in the bloodstream. This dual defense could be critical in preventing infections earlier, creating an extra barrier before pathogens can enter the body.

Since the tissue found between teeth and gums is more permeable than other similar types of tissue, the researchers went ahead and tested their hypothesis. They applied a peptide flu vaccine to unwaxed dental floss and used this to floss the teeth of the mice.

The results were striking. The mice that received the dental floss vaccine produced significantly more antibodies on mucosal surfaces than those given the vaccine under their tongues, and the results were on par with those administering the vaccine via nasal spray.

This approach seems very promising. Many vaccine formulations don’t work well when delivered through the nasal epithelium, and there are safety concerns about vaccines potentially reaching the brain when using that method. Gill pointed out that flossing presents no such risk.

The research team also tested three additional classes of vaccines—proteins, inactivated viruses, and mRNA. They found that the dental floss method effectively stimulated antibody production for all, showing that the efficacy didn’t diminish even if the mice consumed food or water right after the procedure.

Curious about how practical this method could be, the researchers also experimented with humans. By using floss picks coated in food dye, they asked participants to try and push it between their teeth and gums. They found that participants managed to place about 60% of the dye in the gum area, suggesting that floss picks could indeed be a viable way to deliver vaccines into that tissue.

On the cost front, the researchers believe it would likely be comparable to existing vaccine delivery methods. However, there are some limitations to consider. For instance, this method isn’t suitable for everyone; it can only be used on individuals who have teeth. Newborns, who typically start growing teeth around six months, wouldn’t be able to benefit from this method until then. Additionally, the effect of any gum infections on vaccination efficacy remains uncertain, so more studies are necessary to address these concerns.