Painless, easier to administer and more thermostable than traditional vaccines, microarray patches are being touted as the future of vaccination in low-income and pandemic settings. To the untrained eye, it looks like a small round sticking plaster – the sort you might be given after a routine blood test. Pressed onto the skin, the patch feels rough, but not uncomfortable; as if someone had pressed a piece of Velcro against you. "People don't describe it as being painful, and they will certainly overwhelmingly prefer it over an injection," said Prof Mark Prausnitz, director of the Center for Drug Design, Development and Delivery at Georgia Institute of Technology in Atlanta, US.