Do you have any source or proof regarding that "retroactively" claim?
Because AFAIK they only started to bill customers for 6 doses per vial when they received official regulatory approval for the 6th dose. Vials delivered earlier were not affected, so any 6th dose gathered from them was effectively free.
You are correct, it was not applied retroactively:
> Gottlieb, the former head of the FDA, clarified that the change is not going to be applied retroactively, meaning that all vials previously shipped out are counted as containing five doses.
Because AFAIK they only started to bill customers for 6 doses per vial when they received official regulatory approval for the 6th dose. Vials delivered earlier were not affected, so any 6th dose gathered from them was effectively free.