I keep the original locked up because I don't want to lose it! Just. used my phone in NYC, but don't know what Europe requirements are. Thanks! (Going via London to Italy on South of Italy tour in April. Can't wait!)
Last summer/fall we took the originals and kept them in our neck wallets where we also keep our passports, We needed the originals. Treat them exactly like you would your passport. Having backup photos on your phone is helpful.
Copies are rarely acceptable given how easy it is to forge a copy. And, if you look on the internet you will how easy it is to purchase a forged vax card. Still with the original and make a copy for back up purposes.
In Paris in November I had my original CDC card in a plastic badge holder with a lanyard tethered to my crossbody bag.
I didn't want to lose mine either, and this was a guarantee that no one would walk away with it or that I might drop it.
(And enjoy your time in Italy!)
I have a new passport case. It holds the passport on one side and the CDC card on the other.
I laminated my CDC card after both Moderna doses. This was before we knew we’d be getting boosters.
When I got my booster they gave me a brand new card and copied the info from the original card.
Should I even show Europeans the original card with only 2 doses or would that be suspicious?