Measles and rubella are not vaccines (since that label seems so critical in these conversations). The vaccine I guess you are referring to is commonly referred to as MMR.

MMR after a 2-dose inoculation provides less than 100% protection against infection. Infection in cells can occur even after vaccination and vaccinated immune responses such as protective antibody levels have been able to be studied in vitro as a result. Not so "sterilizing and immunizing" if those terms mean blocking all infection.