Why are you so fixated on interpreting data from a placebo group as if that is some stand-alone sample?
Because if you cannot interpret the data from a group, then what good is the group?
If some symptoms are observed in the placebo group, this is an indication that similar levels of symptoms you observed in the vaccine group cannot be attributed to the vaccine.
Not that these people were infected and exposed to different things in their daily lives?
If people in the placebo group tested positive for COVID-19 related antibodies (at a significantly higher rate than what you'd expect from population average), then you should take a serious look at possible sample contamination, unaddressed bias (on prior exposure to COVID-19) in your sampling method, and the reliability of your antibody testing methods especially on false positives, all of which could seriously threaten the validity of your clinical conclusion.
So if some of your placebo group got naturally infected during the course of the 12-18 month phase 3 and naturally developed antibodies, that invalidates your vaccine or shows contamination in your study?
Without a placebo group, you simply wouldn't know something's wrong. So no matter how you look at it, having a placebo group provides valuable data and helps you reach more reliable conclusions.
With a placebo group that yields uninterpretable data, you
still don't know what's wrong and basically have to explain away everything you see. If the placebo group developed antibodies, then it's because they developed them naturally; if they got sick, then it's because they got exposed to something, etc...
Human challenge trials lasting 2 months in a secure facility solves all of these issues.
This is very basic stuff. If you received professional training in experimental design, you should know better.
For mice, it's basic. For people, you need to think instead of opening a textbook, reading that you need control group, so you do a control group. For me, a person, it's disrespectful to haul my ass into the hospital to get my blood time and time again after injecting me with saline when you have something that can potentially vaccinate me.
I've said in the previous post and I will say again, a standard phase 3 in vaccine development, despite time-consuming, is necessary not because we are too much of a coward to test vaccinate and infect a few dozen people, but because an unsafe or unreliable vaccine has the potential to kill even more people than if we waited without one. Not to mention the sociopsychological impact it'd do to the populace on their acceptance of further vaccination.
I didn't say the phase 3 needs to be nixed; I said human challenge trial can be done in parallel to get something out there ASAP. Safety is already established in phase 2, which is pre-human challenge trial. Reliability will be determined in the human challenge trial, over a smaller but controlled group. In the meantime, it's better to have something that at least partially works (or completely) than to have nothing at all until phase 3 ends in 12-18 months.
I simply do not agree with you or Bltzio that this is a standard case that defaults to the textbook approach to experimentation. I think this is a very urgent situation and executive decisions need to be made to speed things up drastically.