How come some vaccines are live and some are inactive?

Vaccines: Most common vaccines are killed vaccines. They are made from the killed form of the bacteria or virus and can not cause you to get the illness from the vaccine. In some cases, MMR and Varivax, we use a live-attenuated vaccine in which the virus is grown in such a way to disable the properties which cause illness. It mostly depends on the best way to develop the vaccine.

The way they work: Sometimes we can fabricate part of the cell wall of the germ in the lab.These are usually what is in inactive vaccines. We haven't been smart enough to do this with all the nasty germs, but find that taking live ones and passing them through stresses that make them too weak to cause disease produces an acceptable vaccine.These are the live ones.>None are perfect, but I consider them the best.