The development of antibodies to a particular antigen (infectious organism); in this case HIV. Seroconversion is a part of the immune response. When people develop antibodies to HIV, they "seroconvert" from antibody-negative to antibody-positive. In other words seroconversion has occurred. It may take from as little as 1 week to several months or more after infection with HIV for antibodies to the virus to develop. After antibodies to HIV appear in the blood, a person will test positive on antibody tests.