The rubella vaccine is a live attenuated (weakened) virus which is usually given as part of the MMR vaccine (protecting against measles, mumps, and rubella). MMR is recommended at 12-15 months (not earlier) and a second dose when the child is 4-6 years old (before kindergarten or 1st grade).
Rubella vaccination is particularly important for non-immune women who may become pregnant because of the risk for serious birth defects if they acquire the disease during pregnancy