I decided to get the second booster (shot 4) before the cruise as a precaution May 1. That provided time to "kick in". We think she contracted it at the symphony May 14, could have been at a restaurant, but we didn't dine out often, we were eating the food we had. We left for the cruise May 15, returning yesterday.
She had started sneezing more than usual and said she had fever off and on, but hardly any real symptoms, we walked all over the place, but she doesn't complain about such things. It was a real surprise when she tested positive May 17 and 18. I never tested positive, never had any symptoms, so maybe it protected me. I'd guess it eased her symptoms. This isn't always an on or off kind of binary thing except for the transport issues.
The funny thing is Lufthansa was VERY strict about mask wearing on the flight, the attendants were chastising folks left and right, who knew the Germans could be that way?
Then you get into the airport at Frankfort and Copenhagen and masks were rare events, really only Asians wearing them. The same was true in Denmark and Sweden. Then Air Canada coming back, masks required, including at the Toronto airport (which was a true mess).
Then ATL and no masks of course, except some Asians.