let's take a step back here and explain why we don't need studies to know that humans are creating antibodies to eliminate the virus, and that there is no ambiguity surrounding the point, at all, whatsoever. and, i'm not going to cite studies, nor am i going to post links, but i'm just going to summarize a high school biology textbook, for the benefits of people that were apparently too lazy to bother.

and, i don't want to hear excuses - if you don't take bio in high school, you're just too lazy to do it. there's no other reason. i'll accept that physics and chemistry are a little esoteric if you're really intent on becoming a lawyer, but high school biology (including evolution) is really so rudimentary that it ought to be mandatory for all five years.

and, the immense ignorance we're seeing in front of us is evidence of the point.

so, how do we know that antibodies work without doing any studies?

the answer is that we get sick and clear the virus.

"but, what about t cells?"

if you clear the virus with t cells, you won't get sick. that's maybe the only thing i've seen come out of this that is mildly surprising; the apparently very high percentage of people that just clear this thing without even sneezing.

but, if you get any symptom at all - headaches, fever, coughs - then that is evidence that your body is producing antibodies.

and, when you defeat the virus, that's proof that it works.

well, unless you want to argue that it just gave up and left.

"meh. fuck this guy, anyways. i'm infecting somebody else."

no. stop. it is that easy.

it doesn't require a study.

when you get sick, you're producing antibodies; when you win, that means they cleared it.

and, when you die, that means they didn't.

source: any middle school science textbook.