I have tried and failed to figure out the current status or future plans to allow vaccinated Americans to transit Schiphol without a negative test result. We are booked on a Switzerland tour the end of Aug and right now awaiting the Swiss vote (23 Jun) regarding vaccinated tourists. Flight reservations to get there are KLM from Atlanta to Amsterdam, then another KLM flight from there to Geneva (about a 2 hour layover so not leaving the airport). The flights were booked thru the tour company last fall with the actual payment due the end of July. I'm hesitant to change itineraries (e.g. fly into CDG) now that airfares are starting to go up.
I don't mind the hassle or expense of a PCR test, just worried about getting the timing right and the results in time.