ABSTRACT
Vaccination, or immunization, is the most cost-effective public health measure to protect against infectious disease-related morbidity and mortality. A vaccine is a biological preparation that improves immunity to a particular disease. Microneedles, produced by microfabrication in various geometries and materials, have recently been extensively investigated for enhanced transdermal drug and vaccine delivery. Microneedles painlessly pierce the epidermis, creating microscopic holes through which drugs diffuse to the dermal microcirculation. The Group of Prausnitz at Georgia Tech in Atlanta have carried out extensive and innovative immunization studies based on stainless steel monument-shaped arrays of five microneedles dip-coated with vaccine. The microneedles were fabricated by laser-cutting stainless steel sheets and were designed to be long enough to penetrate through the stratum corneum and viable epidermis and into the superficial dermis by gentle manual insertion but short enough to avoid pain. The coated microneedles were used to immunize mice in comparison with conventional intramuscular injection at the same dose.
