The Anti-Measles Antibody IgG (Measles IgG) Test checks your blood for IgG antibodies, confirming if you have long-term immunity from a past measles infection or vaccination, indicating you are protected from getting the highly contagious measles virus again, useful for travelers, healthcare workers, or verifying immunity status for school/work. A positive result means immunity, while a negative one suggests susceptibility, requiring a doctor’s interpretation for next steps like getting vaccinated