A friend of mine did the Pfizer trial, and he strongly suspected he had the real thing because he had some pretty strong reactions to it, with flu-like symptoms making him feel awful for a day. He later got an antibody test, and it was confirmed.

I don't know what the poster above was talking about, getting calls to participate in a study. Nobody contacted my wife or I with such offers. I suspect that the poster was lucky to live right in a city where the test was being conducted; those outside of major cities are probably not included in his claim that anyone could participate in the trials.

I know some folks have reactions to vaccines: not everyone does, though. And weirdly, when folks don't know, sometimes the placebo gives them reaction. Pretty much, side effects have to happen more often in the real thing than they do a placebo.

Sometimes it just doesn't work to have double blind: LSD trials, for example, make things pretty obvious. It isn't the case for the flue, though.

You are correct on the trials: most folks don't get called. That said, living outside the city doesn't exclude you from trials in general because they generally need participants with x and/or y. Often, they will pay for expenses to travel, especially if your disease is uncommon or they have trouble finding participants.

that's interesting i didn't think about that! would taking an antibody test be banned for participants? because those who confirm that they received the real shot could change their behavior?