Scientists Develop Needle-Free Vaccine Using Dental Floss

CAMBRIDGE, Mass. — A novel, needle-free vaccine approach using dental floss could change how vaccines are delivered to the body, according to researchers at MIT. This innovative method, detailed in a study in Nature Biomedical Engineering, explores using floss to administer vaccines directly through the gums.

In the study, the scientists applied floss laced with proteins and inactive viruses along the gum lines of mice. The research team observed that this technique initiated a significant immune response, as the gum tissue is highly permeable, allowing vaccine particles to be easily absorbed. Over a 28-day period, the researchers flossed 50 mice biweekly, a tricky endeavor that required two people: one to hold the mouse’s jaw and another to use the floss.

Four weeks after receiving the final vaccine dose, the mice were challenged with a lethal strain of flu. The results were promising; all vaccinated mice survived, while the unvaccinated ones did not. Furthermore, the immune response in the flossed mice was widespread, with flu antibodies detected in their feces, saliva, and bone marrow, suggesting a long-lasting immune defense.

The researchers also noted an increase in T cells in the lungs and spleen of the flossed mice, highlighting the effectiveness of this vaccination method. Next, they turned their attention to humans. They recruited 27 healthy volunteers to floss with dental picks coated in food dye. The dye reached the gum area about 60% of the time, indicating potential for this delivery method.

The mouth and nose serve as primary entry points for many viruses, making them ideal for vaccine administration. Existing needle-free vaccine alternatives have faced difficulties due to the body’s defenses against foreign substances. A floss-based solution could overcome these obstacles, providing an accessible vaccination method.

“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,” the researchers stated.

This technique could improve vaccine acceptance, particularly among those with a fear of needles. Additionally, floss-based vaccines would not require refrigeration, making them easier to distribute, especially in mass vaccination scenarios during pandemics.

The innovative floss-vaccine approach opens new opportunities for widespread immunization, which could play a crucial role in public health.