A year, maybe?
Gonna be a long time for any vaccine to be universally rolled out and for it to have a positive effect on foreign travel. It’s the infection rate, and the government restrictions placed upon which countries you can and can’t travel to without the need to quarantine, that will determine foreign travel for the foreseeable future.
I’m hoping to go to Switzerland in March but the infection rate yesterday was over 8000. In the summer it was less than 100. It’s just exploded everywhere.