The blacks in the Tuskegee travesty were not informed about what was being done to them.
The vets (and/or their families) were informed of the risks and nature of their treatment, and consented. One of the biases in this study is that the vets who received the hydroxychloroquine or HQ-azithromycin were all in desperate straits, while the group that received only ordinary care varied in the severity of their illness. In other words, the study was an apple-pears comparison (both deciduous fruits, but still different in texture and taste).
In brief, there was informed consent, and also unlike the syphilitic black men who received sugar pills instead of real medication, these vets received real medication that is commonly accepted as proper treatment for Covid-19 in many nations.
