As a final note, ID immunization caused more local inflammatory-like reactions than IM immunization. It is possible that because ID delivery occurs in the skin, inflammatory or immunologic reactions are more easily visible than those that may occur after IM immunization, which presents the antigen deep into the muscle layer where an inflammatory reaction would not be visible to the eye (Belshe et al. 2004; Holland et al. 2008; Arnou et al. 2009; Beran et al. 2009; Van Damme et al. 2009 ).