I think waiting for a vaccine is overkill. At some point, you have to let people make up their own minds. There will be a few things to consider: 1) At some point, restaurants, sporting events, and schools will all start back up again. 2) Mass testing and antibody testing will become active. 3) Hopefully some treatments will present statistically significant efficacy. 4) Staying cooped up and without socialization are already resulting in increased suicide rates and are generally unhealthy in the first place.

What 1) means is that people will start coming in contact with people again, even if it means in the background of at-the-door temperature checks, abundant hand sanitizer, etc., and our dances wouldn't be the only risk factor in one's life by far. 2) means that we will be able to make far more knowledgeable decisions on who should go out. It also means that if you do feel sick, you'd be able to get tested and treated early. You'd also be able to know if you're already immune. 3) , especially in conjunction with 2), means that covid-19 becomes less fatal. There are I think something like 300 clinical trials in progress looking for treatments. Some are garbage, but others are showing promise. 4) means that there is pressure from the other end saying that at some point, the danger posed by socializing becomes lower than the danger posed by continued isolation.

While I don't think those will all come at the same time or in quick succession, I think they'll all be true before a vaccine is approved for use in the US. I think 1) is two to three months away, 2) is probably two months away, 3) could be realized by the end of this month (albeit production capabilities would need to ramp up), and 4) is beyond my knowledge base. The kicker, in my mind, is that that means potentially dancing in August? But then it's likely that we'll see a resurgence in fall again, and we'll see if our capabilities mean we go on lockdown again or do the S. Korea approaches of widespread, aggressive testing with contact tracing.