What my teacher said: Well, this is definitely important question – I want to tweak it a little bit to “How does socioeconomic status impact HIV infection?” socioeconomic status is a more robust way to measure social class and will probably be a helpful search term as you look for articles (socioeconomic status is also frequently abbreviated to SES, and typically includes income+education+occupation). Were you thinking of examining this in an international context? You citation is international and your rationale sounds like you were aiming macro – that’s totally fine, but you might need to think through methodology a little more. And you are right class is the strongest predictor of health status in the USA (close second – race)
please just edit the research question to what she is looking for and the details along with it.