[djf]

HIV is a retrovirus. It effectively clones itself into the host DNA in a cell.
It is possible to be infected yet have no antibodies for it.

[srmorton]

I know that HIV is a retrovirus. That has nothing to do with the host's ability to make antibodies against the virus. It IS possible to be infected and have no antibodies, but that is usually early in the course of a disease when the host has not had time to form the antibodies or the amount of antibody is so low that it is undetectable.

BTW, retroviruses do not "clone" themselves into the host DNA. They have a unique enzyme called reverse transcriptase that is able to make DNA from RNA. The viral DNA then causes the host cell to use it's metabolic machinery to make new viral particles.