This serological test measures the titer of immunoglobulin G (IgG) antibodies against the mumps virus in blood serum. These antibodies are produced after natural exposure to the virus or after effective vaccination with the measles, mumps, and rubella (MMR) vaccine. The presence of sufficient IgG indicates protective immunity against mumps infection. This test is used to assess the immune status of individuals, particularly at-risk adults (such as healthcare workers and students), and to monitor population immunity.