Common cold: not worth it, and is caused by a lot of different viruses, making vaccination even harder.

SARS1: the virus was eradicated before trials could complete.

MERS: There are several vaccines in testing, however MERS comes and goes randomly, so it takes a lot of time to gather events.

HIV: Apparently there's a trial in Uganda going on since quite a while, which looks better than the past ones (which were failures), but with HIV, it takes years to see if it works or not

That said, betting all your options on a vaccine is not what I'd call sound policy. In fact, there are several drugs in the pipeline, but few if any report that.