Ultrasound can push vaccines into the body without needles

Vaccines can be delivered through the skin using ultrasound. This method doesn’t damage the skin and eliminates the need for painful needles. To create a needle-free vaccine, Darcy Dunn-Lawless at the University of Oxford and his colleagues mixed vaccine molecules with tiny, cup-shaped proteins. They then applied liquid mixture to the skin of mice and exposed it to ultrasound – like that used for sonograms – for about a minute and a half. At first, the ultrasound pushed the mixture into the upper layers of skin, where the shape of the proteins caused vaccine-filled bubbles to form. As ultrasound kept hitting the skin, those bubbles burst and released the vaccine. As the experiment went on, the action of the bubbles breaking also cleared some dead skin cells, making the skin more permeable and allowing more and more vaccine molecules make it through. A needle pushes vaccine molecules all the way into the muscles...