A measles titer is a specialized blood test that determines an individual’s immunity to the measles virus. Its purpose is to ascertain whether a person possesses sufficient protection against measles, a highly contagious respiratory disease.
What a Measles Titer Reveals
The measles titer specifically measures the presence and level of immunoglobulin G (IgG) antibodies in the bloodstream. These IgG antibodies are proteins produced by the immune system after a prior measles infection or successful vaccination with the measles, mumps, and rubella (MMR) vaccine. Their detection indicates an individual has developed immunity, meaning their body remembers the virus and is equipped to fight it off if exposed.
Why a Measles Titer is Recommended
A measles titer is recommended in situations requiring proof of immunity. Healthcare workers and college students are often required to demonstrate immunity due to increased exposure risk in close-contact environments. Individuals planning international travel also need this test, if visiting areas where measles is more prevalent. Additionally, people unsure of their vaccination history or unable to locate immunization records undergo a titer test to confirm their immune status.
The Measles Titer Procedure and Results
Obtaining a measles titer involves a blood draw from a vein in the arm. The blood sample is sent to a laboratory for analysis, where the level of measles IgG antibodies is measured. Results are reported in one of three categories to indicate immune status.
A “positive” or “immune” result signifies a protective level of antibodies, indicating sufficient immunity against measles. Conversely, a “negative” or “non-immune” result means protective antibodies were not detected, suggesting susceptibility to measles infection. An “equivocal” or “indeterminate” result indicates antibody levels are too low to confirm immunity, falling into a borderline range.
Actions After Your Measles Titer
The next steps following a measles titer depend on the test results. If the titer indicates a non-immune or equivocal status, vaccination with the MMR vaccine is recommended to establish protection. For those confirmed immune by the titer, further action is not needed, as they are considered protected against the virus. It is advisable to discuss your specific titer results with a healthcare provider to receive personalized guidance and ensure follow-up.