The cards are a very simple form printed on card stock with the data filled in by hand.
So any middle school kid with an ipad and printer could crank these out in about 15 minutes.
20 years ago (!) before driver licenses had security chips, bar codes, etc at the college campus my daughter was at, you could buy a fake license for about 40 different states.
Yes I got my vaccine and card and the card is laughably easy to forge/fake