As a person who has done HIV research since 2001 and got my MPH, I can honestly say that there are so many avenues to do HIV research! It depends on what aspect you would like to become involved in. clinical? pharmaceutical? prevention? outreach? health promotion? sexuality research?
The exciting thing about HIV is that it touches upon so many different aspects of public health, more so than other diseases (no one wants to address sex, sexuality and drugs!!!!). I've been abroad to do research, and if this is an option, I would suggest finding a program organized in America, by Americans that place you with sister organizations overseas.
Contact me if you would like to talk about some resources. Good luck!