Traditionally, when someone says "vaccine", the image of a syringe and needle usually springs to mind. But injections need trained staff to administer them, and they're unpleasant, even for people who are not scared of needles. So vaccines you can inhale sound altogether more attractive. And that's what researchers at Rutgers University in the US have been working on. They've found a particular clutch of chemical compounds that are very good at passing harmlessly through the lungs and entering the bloodstream where they can interact with the immune system. What's exciting is that these... Like this podcast? Please help us by supporting the Naked Scientists