Atopic Dermatitis (AD) is a chronic inflammatory skin disorder in which the skin becomes extremely itchy and is susceptible to recurrent skin infections. AD is thought to occur from a combination of immunological, genetic, and environmental factors. Individuals with AD are at risk for developing a severe and widely disseminated infection called eczema vaccinatum (EV). EV is caused when the live attenuated vaccinia virus in the vaccine reproduces and spreads throughout the body. Individuals with AD lack certain antimicrobial peptides, specifically cathelicidins.