I have very little background in Medicine, pardon me for that. I came across this reference recently. Loosely speaking, this study aims at testing the effect of azithromycin and hydroxychloroquin for treatment of COVID-19.
In the reference, they claim to have tested the effectiveness of combination of azithromycin and hydroxychloroquin on COVID-19 patients. They measure the viral load in patients after a few days and determine the effectiveness of the combination using that and they compare it with a no intervention group. My main question is, how important is it to account for something like placebo in this study if a no intervention group is already present? I would guess, if one is using a measure like viral load, the effects of placebo on it should be negligible. Is that correct? From what I know, placebo would play a significant role if their metric of evaluating recovery would be something like measuring the body temperature or relief in throat etc. which are the symptoms of COVID-19.
With the help of my friend, I found this reference(I do not understand the jargon) which claims that, for a bacterial infection, the immune response is causally linked with reward mechanisms which mediate positive expectations that are a part of placebo. Is this result significant enough to affect the consequences of the study on COVID-19(linked above) drastically?