We are flying into Zurich from the United States next month. I am not clear on what kind of documentation I need to prove I was vaccinated. Is the card I got at the time of vaccination all I need?
Not to be a jerk, but that's the million dollar question. Things are changing on almost a daily basis. Have you checked the Swiss embassy page for any information?
I'm not sure that governments have yet decided on a "vaccination passport" (or whatever they want to call it?), although they are working on it. At the moment your vaccine card would be your best bet, and hopefully the Swiss authorities would accept it.
This is one app that may offer a solution but AFAIK it's still being tested - https://www.iata.org/en/programs/passenger/travel-pass/ .
There are a few forum members traveling to Switzerland this month. I am sure we will hear if the CDC card is not accepted.
Why not call the Swiss Embassy and ask?
Your US vaccine card works fine from what the Swiss government indicates. You should visit their sites, BAG.ch sites for more info. You have to fill out a form to enter. There is a whole thread that covers most of this in this forum though it is focused more on those of us transiting through LHR to get to Switzerland, but it has info on the various sites to check. We also have the digital pass from California and will take both that as well as our CDC forms.
I am leaving direct to Zurich in 4 days. As of today you only need to show the CDC card showing that you are vaccinated.
Considering the old-fashioned ink and paper CDC card is really all there is, it's all there is