Could we all please agree that we are waiting for the virus vaccine, not waiting on the vaccine? We wait for a train (while waiting “on” the platform). I think I would need to be a gymnast to wait on the train (especially while it’s moving . . . ). We wait for our friends to arrive. We wait for the box to be delivered. We wait for the movie to start.
One small exception is a restaurant table. Customers wait for a table. The server waits on the table. The server certainly isn’t waiting for a table, so I guess “on” is the only alternative if we are going to use the word “wait” in that situation. Imagining the server standing on the table while we decide what to order is probably going to make me laugh the next time I get a chance to go to a restaurant with a bunch of folks.
Whenever that will be . . .