The patch is printed with 100 microneedles (each a teeny 1.5 microns, a fraction of the 70-micron diameter of a human hair) that are coated in a liquid form of a vaccine and then dried, making these patches easy to transport and store. The patch delivers the vaccine directly into the skin where there are more immune cells than exist in the muscles or area on the arm between skin and muscle where conventional needles deliver vaccines.

A significant percentage of adults don’t get vaccinated because they are afraid of needles. The Centers for Disease Control and Prevention estimates that one in 10 people may have delayed their COVID-19 shot to avoid a poke in the arm.

In mouse studies, the patch resulted in a 50-times-greater immune response than subcutaneous vaccines.