Seron scar

As a serological scar is called the serological detection of antibodies in the blood that prove an expired, previous or old infection. In the case of many infections, the detection of IgG antibodies cannot, strictly speaking, distinguish between vaccination and previous infection, which is why the term e.g. B. is limited to the detection of the anti-HBc antibody in a hepatitis B virus infection or the detection of antibodies in infections without a known vaccination.
The term scar is used in this figurative context because the antibodies are usually a lifelong characteristic in the patient's blood.