Which first principles are you using to come to that conclusion?

From a practical perspective, there seems to be no appetite in the medical community to attempt this. We have vaccine candidates now, and the consensus opinion seems to be that we should go through the trial process. There just isn't much room to shorten the timeline without cutting corners and safety and efficacy verifications. Unless we learn something dramatic and terrifying new about this virus in the near future, I don't see what would cause this calculus to change.

Before administering a vaccine into everybody, we must first make sure it's not worse than the disease (on average, what is a very high var).

This test takes some time, so no, not on the next 6 months. One can realistically expect it by 2022, if we are willing to rush and accept some risk.

By the way, 6 months is how long it takes to create a batch of flu vaccines.

Huh?

From first principles there is no reason why anyone should think that their won't be 2 billion vaccines tomorrow (perhaps via divine intervention). Heck, from first principles I'm not even sure Australia exists (Maybe Australia is a giant hoax. After all, i have never been there.)

Proving things from first principles is really hard. The fact you weren't able to disprove a statement from first principles is not strong evidence the statement is actually true.

It’s also possible no vaccine will be discovered as there are no coronavirus vaccines.