[Question] What’s the status of third vaccine doses?

People seem to think that getting a third mRNA vaccine dose, or “booster shot”, substantially increases immunity after 4ish months from your second dose.

  • Is it currently “illegal” to get one, or is it just the policy of all current pharmacies and vaccine distributors to refuse to give them?

  • Is there any shortage of vaccines in the US at this point? Would getting a booster shot counter-factually cause another person to get a dose later?

  • Is there chance that booster shots will become commonly available in the next month? Is it even in the Overton window of things that politicians are bothering to think about?

  • Lastly—because I assume the answer is no—is there any reason to think that getting a third shot of a different vaccine would be biologically dangerous?