Syringe needles are a major barrier to vaccine acceptance. A 2021 study found that more than a quarter of adults in the United Kingdom are afraid of injections, leading to a higher rate of vaccine hesitancy, particularly with emerging diseases like COVID-19. Intranasal vaccines (those that are sprayed or dropped into the nostril) are one solution, but they aren’t perfect: Their efficacy can be more challenging to track, and pharmaceutical companies tend to put fewer resources behind them. And while scientists are working on edible vaccines, they’re not really “a thing” just yet.
Needle-free vaccination patches could fill this gap. Vaxxas, a biotechnology company based in Australia, is officially scaling up the production of its vaccination patches in preparation for late-stage trials. If the trials go well, the product could make its way into medical offices in as little as three years.
Vaxxas’ vaccination patch is formally known as a high-density microarray patch, or HD-MAP for short. Each thin, dime-sized HD-MAP is covered in thousands of microprojections, or spikes that are roughly 0.25 millimeters long. These microprojections are coated in dense populations of viral proteins, which are what “teach” the body to defend itself against a disease. The patch comes in a foil pouch that can be tucked into a plastic application device. When a medical professional pushes on the outside of the device, a pre-loaded spring effectively stamps the HD-MAP onto the recipient’s skin.
This month Vaxxas completed a Phase 1 human clinical trial that used HD-MAPs to deliver the COVID-19 vaccine. The patches’ microprojections contained HexaPro, an updated version of the spike protein found in Moderna and NovaVax vaccines. The administration of the HD-MAP HexaPro was treated as a booster, as all 44 trial participants had already received three doses of the COVID-19 vaccine. A month after the HexaPro was administered, participants were found to have eight times the amount of relevant antibodies they had from their original vaccine doses. None of the participants experienced serious or severe side effects.
Vaxxas claims the HD-MAP is capable of producing an even better immune response than that produced by a conventional syringe vaccine, thanks to the microprojections’ tendency to alert the immune system in a way that shifts vaccine components toward the lymph nodes. The plastic applicator is also so easy to use that it wouldn’t require special training the way a syringe does. While COVID-19 vaccines are a priority for Vaxxas, seasonal flu vaccines are also on the company’s radar.
