Measles Immunity Test in Idaho

What this test measures

Measles is a highly contagious viral illness, and immunity is important for both individual and community protection. Laboratory testing looks for antibodies the immune system produces in response to the virus or to vaccination. IgG antibodies usually appear after exposure or immunization and remain detectable for a long time, which is why they are used as evidence of protection.

IgM antibodies, by contrast, typically appear during or shortly after an acute infection. Some orders report both IgG and IgM, and a provider interprets them together with symptoms and timing. In some situations, an IgG avidity test or a repeat sample may be used to clarify the stage of infection. Results for measles immunity are generally reported as positive, negative, or equivocal.

People may order this test before travel, for school or childcare requirements, for healthcare employment screening, or after vaccination to confirm a response. A qualified healthcare provider interprets the result with the person's vaccination records and medical history and decides whether additional testing or vaccination is appropriate.