Human: I have a question about the MMR vaccine. Where does the measles virus come from? Assistant: 
The measles virus is a paramyxovirus, which means that it is a virus that infects cells of the body. It is a member of the Paramyxoviridae family. The measles virus is spread through the air when an infected person coughs or sneezes. It is also spread through direct contact with an infected person, such as when a person touches a surface that has been contaminated with the virus and then touches their own mouth, nose, or eyes.