>Add in a mandatory annual booster shot and you got yourself a nice little business going there.

Since we're talking economics, want to know of another good business? Coffins and funeral homes.
I'm sure there are a few competing companies that stand to make a killing (pardon the expression).

But hey, want to change things? Prove Pfizer and Moderna wrong. :)

There's power in numbers. All it will take is a few hundred thousand people to decide they'd rather risk it than pay for an annual shot - and believe me, prices and profits will DROP REALLY FAST. :)