Q: Shots hurt. Why do
I need to get a vaccine through a shot? Why can't I just rub the vaccine
on my skin? A: In order for the vaccine
to work, it must enter your bloodstream so that it can spread throughout
the body. However, one of the body's first lines of defense is the
skin, which is composed of the epidermis (the thin outer layer)
and the dermis (the thicker inner layer). The skin acts as a barrier
to prevent the entry of pathogens. Unfortunately,
the skin also prevents vaccines from entering
your body. So, in order to inject the vaccine
into your bloodstream, a shot is required to puncture your skin.