You need to enter a new type in the immunization drop down in Administration, Admin Tab on the right. Then you would need to add a new rule for Measles as shown. (For those that have Mumps and Rubella Titer, then add it as well, each one as a new rule.) Please note if someone is immuned for all three (3) then you would have to add a date to the MMr vaccine and a temp medical so that he is considered immunized, and would not show up as missing.