Since big pharma has been unblinding and vaxing placebo groups, what can they glean from trials without controls? Are the continuing trials mostly for show?

After a little digging and feedback, this appears to be the answer. https://twitter.com/benmagelsen/status/1381401706060148738?s=20

Since we may not get a lot more, the data in the FDA briefings is interesting. If you look at the placebo groups and rates of infection, you may be surprised.
https://www.fda.gov/media/144245/download
https://www.fda.gov/media/144434/download
https://www.fda.gov/media/146217/download

If you want to learn more about the risk/benefit shown in the trials, this video by DR. Brown is also worth watching. https://twitter.com/My2puppies1/status/1381419504060801024?s=20

This article that calculates Actual Risk Reduction "ARR" is worth a quick read. While the FDA recommends ARR in addition to Relative Risk Reduction "RRR", at ~1% it's not surprising big pharma decided to leave this calculation out of the briefings. https://twitter.com/My2puppies1/status/1381419767794388992?s=20