The molecular mechanisms of Chicken pox:

Replication of the upper respiratory mucosa epithelial cells begins this VZV infection. This causes the highly contagious rash that is easily spread throughout the body. Infected T cells then send the virus throughout the body were it is able, such as the tonsils and lymphoid tissues. These infected T cells spread the VZV through the bloodstream.

What vector does it use to get from host to host?

This virus is airborne. It is spread by respiratory particles.