It's pretty unlikely that it would be communicable after such a long period without being specifically preserved under controlled conditions.

Live viral vaccines are typically shipped in a preservative and kept on dry ice during transit after which they are kept in a freezer until immediately before administration. This is one of the reasons it's so difficult to vaccinate large swaths of underdeveloped areas.

I can't imagine a vial in a closet could maintain a culture 'on accident' for more than a few months.

Possible, but not incredibly likely unless it was prepared via freeze-drying for long-term storage. I wouldn't want to huff it, though.