expect this: if the government won't take the aggressive steps required to protect the elderly from the general population, which is in the process of building natural immunity, then they are going to die at alarming rates and it is going to look like italy.
and, it will not be the fault of young people that would not stay in - it will be the fault of governments that did not act intelligently, who promoted stupid policies designed to minimize disruption on the vulnerable at the expense of the majority and ignored sensible, effective ones that would directly target them, as they need to be targeted.
what do you think we did for the millions of years before we understood vaccines? this isn't the bubonic plague. this isn't ebola. it's literally the common cold, albeit on steroids. it has a less than 1% death rate.
what we did was build up natural immunity. and, that's what we will need to do now.