How long will this go on for?

I heard news reports that experts tell us we will need to keep some form of lockdown in place for a year. Let's see if I can use the back of an envelope to understand where this comes from.

Before a vaccine, we will all get this disease and it will kill a certain number of us. 

Let's assume a 0.83% death rate greater than the background 1% (I'm using the numbers from the Imperial Paper by Neil Ferguson). There is a lot of discussion about whether in the long run, this 0.83% will simply front load the 1% and "get them anyway". There isn't enough data yet to know, so I will continue with the 0.83% death rate assumption. 

In the UK, a country of 66 million, this means an extra 550,000 will die. (Incidentally, currently, around 15,000 or about 2.7% of the total expected death toll has occurred in the UK.)

If we continue to suffer around 900 deaths per day as we are at the moment, it will take 611 days for the infection to run its course.

If we allow the death rate to increase to 5,000 per day, 110 days would be needed.

How it goes will hinge on how the various lockdown measures are relaxed. If we lockdown strongly and remain focused on minimising numbers of Corona Virus deaths, it will take more than a year to get free of it. If we relax the rules and allow the deaths to go up significantly more than we are experiencing at the moment, we have a chance to get free of this much sooner. 

Of course, this is all appalling and difficult to talk about. Most of the public is still fixated on absolute numbers and it will take a lot of communication to move them away from this.

The harsh truth is that the numbers have to go up if we are to get through this quickly.