Skin Tissue Most Important Part of the Immune System?

Originally it was believed that the most effective way to give a vaccine is through the muscle. Due to recent discoveries, scientist are beginning to believe that vaccines should be given through peripheral tissue in the skin. "The researchers showed that a population of immune cells called resident memory T cells, which are present in parts of the body that are in contact with the environment, such as the skin, gut, and lungs, mediate an immune response far stronger than circulating, or central, memory T cells in the blood stream." (http://the-scientist.com/2012/02/29/skin-deep-immunity/)  Because of this vaccines could be more effective if given through those cells. In a recent study resident memory T cells and circulating T cells were pitted against each other to see which one was a more powerful part of the immune system and resident memory T cells won. The cells spread from the site of the infection to other parts of the body and stay there for six months to help heal the infection. The next step is for scientists to find out how long the cells reside in the skin and new methods of vaccination.http://the-scientist.com/2012/02/29/skin-deep-immunity/