This test is used to aid in the determination of serological status to measles virus. A positive result generally indicates exposure to measles virus or previous vaccination. A positive result is considered adequate laboratory evidence of measles immunity. Persons with an equivocal serologic test result do not have adequate presumptive evidence of immunity and should be considered sesceptible unless they have other evidence of measles immunity. Documented age-appropriate vaccination supersedes the results of subsequent serologic testing. If a person who has two documented doses of measles-containing vaccine is tested serologically and is determined to have negative or equivocal measles results, it is not recommended that they receive an additional dose of vaccine. These individuals should be considered to have presumptive evidence of immunity.