MMR Titer Proof of Vaccination Guidelines

Laboratory Evidence of Immunity

The Centers for Disease Control and Prevention (CDC) recommends ordering serologic testing for IgG antibodies to measles, mumps, and rubella using any standard, licensed enzyme immunoassay (EIA) 1, 2, 3
Any antibody level above the standard positive cutoff value of a licensed assay is considered acceptable evidence of immunity 2, 3
The demonstration of IgG antibody by any commonly used serologic assay is acceptable evidence of immunity according to the CDC 2, 3
For measles, positive measles IgG antibody detected by any standard serologic test is evidence of immunity 3
For mumps, demonstration of mumps IgG antibody by any commonly used serologic assay is evidence of immunity 2
For rubella, laboratory evidence of immunity is defined as positive rubella IgG 4, 5

Persons with "equivocal" serologic test results should be considered susceptible to measles unless they have other evidence of immunity 3
For healthcare personnel with documented MMR vaccination who test negative or equivocal, documented age-appropriate vaccination supersedes the serologic results—they should still be considered immune 4, 5, 6
Do not order titers for persons with documented age-appropriate vaccination unless the medical facility considers it cost-effective 4, 5

Written documentation of 2 doses of live measles or MMR vaccine administered at least 28 days apart is alternative evidence of immunity for measles 6
Written documentation of 2 doses of live mumps or MMR vaccine administered at least 28 days apart is alternative evidence of immunity for mumps 6
Written documentation of 1 dose of live rubella or MMR vaccine is alternative evidence of immunity for rubella 4, 5

All healthcare personnel should have presumptive evidence of immunity documented and readily available 4, 5, 6, 7
Approximately 4-10% of healthcare personnel lack measles IgG antibodies, even among those born before 1957 3
For healthcare workers with documented vaccination who test negative/equivocal, do not give additional doses based on serology alone—consider them immune 4, 5, 6