Question - The vaccine is an attenuated vaccine. This means it is a live virus but far less virulent. Varivax is a single-antigen varicella vaccine. Two doses are recommended subcutaneously (via a needle) and must be spread out at least 3 months. Thus, the first does is typically given to children ages 12-15 months and the second dose can be given between the age of 4 and 6. Another vaccine category is inactivated. Inactivated vaccines are non-replicating cells or viruses. They can be the whole cell or virion or just a piece - a sugar or protein for example.
Name one advantage of administrating an attenuated virus over an inactivated. Also, why do you think two doses are required for successful vaccination?