Seroconversion
（重定向自Seroreversion）
In immunology, seroconversion is the time period during which a specific antibody develops and becomes detectable in the blood. After seroconversion has occurred, the disease can be detected in blood tests for the antibody. During an infection or immunization, antigens enter the blood, and the immune system begins to produce antibodies in response. Before seroconversion, the antigen itself may or may not be detectable, but the antibody is, by definition, absent. During seroconversion, the antibody is present but not yet detectable. Any time after seroconversion, the antibodies can be detected in the blood, indicating a prior or current infection.