Transdermal delivery is a safe, noninvasive method of administering vaccines directly onto bare skin, offering several potential advantages over traditional needle delivery. This technology is limited by the relative inefficiency of transport of large-molecular-weight vaccine antigens across intact skin. Recent evidence has shown that this barrier can be overcome by properly structured nanosized particles (nanocarriers). The specialized assembly of each type of nanocarrier gives each unique properties and different interactions within the stratum corneum. The use of nanocarriers for vaccine delivery is a platform technology, applicable to delivery of a variety of existing and potential vaccines.