All the scientists I've heard suggest 12-18 months at the earliest for a vaccine - although apparently it would previously have taken 20 years.
I think it's very difficult to put a country into lockdown for 18 months because of the social and economic impact. How do we buy food and essential items? How is that provided to us? What about all the people who have to work in essential services?
I guess there is nothing from stopping each individual family choosing to go into lockdown if they think it is right for them and circumstances mean they can afford it, etc.
It is clearly a very grim and serious situation.