Innovative Flossing Method Offers New Vaccine Delivery System for Mice

In a groundbreaking proof-of-concept study, researchers have demonstrated an innovative method for delivering vaccinations through dental floss, successfully immunizing mice against influenza. Published on July 22, 2023, in the journal *Nature Biomedical Engineering*, this research explores the potential for a needle-free vaccine delivery system that could significantly alleviate the discomfort and logistical challenges associated with traditional injection methods.

The study, led by Rohan Ingrole, a chemical engineer at Texas Tech University, involved flossing the teeth of mice with dental floss coated in inactivated flu viruses. This novel approach capitalizes on specific areas in the mouth that allow for enhanced absorption of vaccine components, particularly the junctional epithelium (JE), which is located between the teeth and gums. This area is known to be highly permeable, making it an ideal site for vaccine delivery.

According to Ingrole, "The floss-based vaccination induced both systemic and mucosal immunity, while conventional intramuscular shots largely stimulate systemic immunity." This dual immune response is crucial as many pathogens enter the body through mucosal routes. Consequently, the flossing technique may offer an advantage over traditional vaccine administration methods.

The experiment involved 50 mice, which were vaccinated by having their teeth flossed three times over a span of six weeks. Following the vaccination period, the mice were exposed to an active flu virus, with all vaccinated subjects surviving the exposure, while the unvaccinated control group did not. The results indicated that the vaccinated mice developed a robust immune response, producing significant levels of antibodies and immune cells throughout their bodies, as well as in their saliva and feces.

This study not only opens a pathway for developing needle-free vaccines but also has implications for resource-limited settings where trained medical personnel or sterile conditions may not be readily available. The researchers suggest that this method could facilitate rapid vaccination efforts during outbreaks, potentially allowing for home delivery options.

The researchers also conducted preliminary tests in human volunteers, using a fluorescent marker to demonstrate that a portion of the coating could be transferred to the JE area during flossing. Harvinder Gill, a bioengineer at North Carolina State University and senior author of the study, emphasized the importance of this finding, stating, "The next step is to translate the research to larger animals, which can then lay the foundation for human testing in the near future."

While the floss-based vaccine holds promise, it is essential to conduct further research to compare its efficacy against traditional vaccination methods directly. The implications of this research extend beyond veterinary applications, as it could revolutionize how vaccines are delivered to humans, especially for those who are needle-averse or live in areas with limited access to healthcare.

In conclusion, this innovative method of using dental floss as a vaccination delivery system represents a significant advancement in immunization strategies. With further research and development, it could lead to more accessible and less painful vaccination options, potentially transforming public health responses to viral outbreaks.