He said that both groups got the same counseling, so the counseling effect was controlled for between the groups. You can use this information to talk about the difference between the two groups, but not between the intervention group and a group in society that has not received the counseling.

According to my professor (and my other research mentor he works with), there are a few reasons these studies are allowed to be done with a placebo group. First of all, there is no acceptable proven HIV vaccine or medical treatment that is a pharmaceutical preventative of HIV transmission. Secondly, both groups do get a demonstrable benefit by participating in the study – which is receiving counseling and attention from the personnel involved in the study.