I think we still don't know, but that's the main point- we need to know how this virus works before we can think about going back to normal
That's the aspect that bugs me. The west seems to be adopting an attitude that it can't be beaten. It seems to be largely economically biased. Eg can't stop it from arriving. Airport etc controls from effected countries no use as some passengers will have visited other countries on the way or might choose to go to a country where flights to here are allowed. Only answer would be to stop all travel into the country early. The plan also mentions that 70% of arrivals will go to major population centres around the entire country so it will spread. No thoughts about travel restrictions in the UK but needed when the standard depress the infection curve methods are applied. This as they see it is the way to go.
So say we have a vaccine. How effective it is depends on how long the immunity lasts and if the virus is still around. The results of that approach could still be a long way from normality. How can social distancing go if 65million people might need regular jabs? If the virus has gone they don't need jabs or some wonder pill or magic bullet that makes recovery easier. The virus can't exist without hosts.