It was not "put on hold", rather as many experts expected, especially with the state of the current administration, mass distribution and coordination is a clusterfuck. Which, to be fair, is a very challenging problem with a lot of minutia and moving parts. But "your amazon product will take another day to ship" is very different from "your amazon product is broken".

If you're worried that it was rushed by US politics: the "Pfizer" vaccine was made by Biontech, a German company, and has also been accepted (earlier, even) by regulators in Canada and the UK.