We visited Belgium, France, Luxembourg, Netherlands and Mosel, Germany a few years ago. We left at the beginning of September. I tried to get a flu and COVID vaccine before we left. No one in my area had the flu vaccine at that point. My doctor told me that she didn't feel the COVID vaccine would be worthwhile for me because the new one hadn't come out, and I had had a booster about 8 months earlier. At my insistence, she ended up approving the COVID vaccine for me. My husband's doctor wouldn't approve one, he didn't think it worthwhile given the new one would be out shortly.
We were in the Champagne region at the end of our trip. We took a tour/tasting at a place with tunnels and underground storage that was used during WWII. As I went down the tight stairway, I thought, this is COVID waiting to happen. And, two days after returning home, my husband and I had COVID. We were probably contagious (no symptoms) on our return flight, which makes me sad. I hate to think I might have gotten someone sick.
A few people told me that Europe had the new strains before the U.S. So we very likely were infected with strains that had not yet reached the U.S. Just like me to be "cutting edge". (JK)
This year, we are going to England at the beginning of September. I turn 65, 9/1, so I'm not even sure I can get a COVID shot in August before I leave. Thank you to Secretary Kennedy. . .
So that's our experience. To the OP, you are in Austria less than 2 weeks. Studies seem to indicate that patients do not build full immunity until 2 weeks or so after the vaccine. Trust me, I want to avoid another bout of COVID as much as the next person, but I don't feel like you will build enough immunity to make it worth while.