Now, in both of these cases, in the natural case and in the artificial case we obtain the same exact result. We essentially either inject or somehow obtain these antigens. Our immune system begins to develop antibodies as well as memory cells that contain a copy of that antibody in case we are ever reinfected. And that's how we develop something called active immunity. So vaccines are normally developed in laboratories by many different methods that we're not going to focus on in this lecture. Typically, the pathogen is inoculated which means that it is changed in some way or form as to ensure that not too much damage is actually taken by the body so that we don't feel the same exact bad effect that we would normally feel in the natural process of infection.