Needlephobes, cower no more! Researchers at the Georgia Institute of Technology and Emory University have developed a vaccine-delivery patch that dissolves painlessly into your skin — no muss, no fuss, and no hypodermic needles or sharps to dispose of. You don’t even need medical personnel to inoculate someone. Slapping on the patch is virtually idiot-proof, allowing self-administration of vaccines during a pandemic or large-scale, walk-through immunization programs in developing nations.
A single patch contains hundreds of microscopic needles — each only 650 microns long — made from a polymerized blend of vinyl pyrrolidone and freeze-dried vaccine. Pressed against the epidermis, the microneedles quickly dissolve in bodily fluids, leaving behind only a thin backing that washes away in water.
Unlike traditional hypothermic needles, which deliver the vaccine into muscle, the patch penetrates the outer layers of the skin. Still, the latter may be a better point of entry, according to Richard Compans, professor of microbiology and immunology at Emory University School of Medicine. “The skin is a particularly attractive site for immunization because it contains an abundance of the types of cells that are important in generating immune responses to vaccines,” he says.
Although mice that were vaccinated by skin patch fought off an infection just as well as mice that were injected, researchers noted they also had far less viral activity in their lungs than their injected brethren. This suggests that the patch encourages a more effective immune response.