Most vaccines available to the public are given with a needle and syringe plunged deep into a large muscle, but muscles actually contain very few immune cells and some researchers believe other routes of administration might be more effective. The Nanopatch is a recently developed technology to deliver vaccines directly to the skin that contains more than 3,000 very tiny needles on a patch smaller than a postage stamp. Skin is rich in antigen presenting cells, which present pieces of foreign bodies, either infectious pathogens or the contents of a vaccine, to other immune cells to spur a specific immune response. VIDD affiliate investigator Dr. David Koelle and colleagues wondered whether the Nanopatch might provide better protection against herpes simplex virus-2 (HSV-2), a common sexually transmitted infection for which no effective vaccine currently exists.
Koelle and colleagues, working with the inventor of the Nanopatch, Dr. Mark Kendall of the University of Queensland in Australia, compared delivery of a DNA-based HSV-2 vaccine using the Nanopatch or standard intramuscular vaccination in mice. The researchers inoculated the mice with a vaccine containing the gene coding for a piece of the HSV-2 protein gD2, either by injection in the leg muscle or Nanopatch applied to the ear. They then assayed the animals’ immune responses to the vaccine, and then challenged these animals with HSV-2 and looked at their survival. They found that the mice showed strong antibody and T cell responses to both vaccine routes, and that the Nanopatch provided protection against death in lower doses than the intramuscular injection, indicating that this new technology may be a promising avenue for future HSV-2 vaccine development.
Kask AS, Chen X, Marshak JO, Dong L, Saracino M, Chen D, Jarrahian C, Kendall MA, Koelle DM. DNA vaccine delivery by densely-packed and short microprojection arrays to skin protects against vaginal HSV-2 challenge. Vaccine. 2010 Nov 3;28(47):7483-91.
Chen X, Kask AS, Crichton ML, McNeilly C, Yukiko S, Dong L, Marshak JO, Jarrahian C, Fernando GJ, Chen D, Koelle DM, Kendall MA. Improved DNA vaccination by skin-targeted delivery using dry-coated densely-packed microprojection arrays. J Control Release. 2010 Sep 17.