A shaving blade unit having a housing that includes a primary cap, a primary guard, an upper face, and a rear face. An exemplary system comprises a shell and a light assembly. Also provided is a method of inducing a CD8 and a CD4 memory T cell response against an antigen using an adenovirus vector expressing an antigen or an immunogenic fragment thereof. Self-defoliation advantageously obviates the need to apply defoliants prior to harvesting.