There isn't one specific medical term for a scientist who studies AIDS. However, depending on their area of focus, they could be called several things:

* HIV/AIDS researcher: This is a general term for someone who studies HIV and AIDS.

* Virologist: A virologist is a scientist who specializes in the study of viruses, including HIV.

* Immunologist: An immunologist studies the immune system, which is crucial in understanding HIV and AIDS.

* Infectious disease specialist: A physician or researcher specializing in infectious diseases, including HIV/AIDS.

* Epidemiologist: An epidemiologist studies the distribution and determinants of health-related states or events in populations. They might focus on the spread of HIV/AIDS.

The most accurate term depends on the specific area of research the scientist is involved in.