The advantages of intradermal (ID) vaccine administration have been well documented but difficulties in performing ID vaccination using existing techniques and equipment have limited it's clinical application. In the present study, a new ID injection technique and associated microinjection system is described and evaluated in a swine and Human models. Clinical investigation models included: injection site imaging (X-ray and 3D ultrasound echography), histological examination of injection sites, fluid injection volume accuracy measurement, subject' perceived pain and local skin reactivity were specifically developed. These evaluations showed that microinjection system can make the practice of ID vaccination easy to perform, reliable and safe, thus setting the stage for broader clinical application of ID vaccine delivery.