I remember seeing a very early briefing with Hancock describing how they were going to do intermittent lockdowns to ensure that people got infected for herd immunity but to manage it in waves so the NHS didn't get overwhelmed. I don't have proof, but I swear I did not imagine this. I have a very good memory for certain things and did not imagine it early on. There were graphs about how many seriously ill people the NHS could cope with at any one time and everything (and the approach was never about preventing people getting ill, just how many needing intensive care/ventilators/oxygen could be coped with at any particular time so it didn't overwhelm the NHS)
Funny you should mention that. First a little background:
There were only a few days in March where they explicitly talked about herd immunity, in the contect of getting it all out of the way with a single wave. As part of explaining the original plan A, and then that plan went down badly and was incompatible with reality so they pulled the plug on it within days. And part of pulling the plug involved publicly denying that herd immunity was ever part of the plan. Hancock was one of the first to be sent out to deliver that message.
The next stage was messy because plan B was botched together over the next week+. And they tried to make it sound like it wasnt a giant u-turn, so aspects of the original language and explanations were retained and then only moved away from in stages. Due to the previous shitstorm its unlikely they used the term herd immunity at that stage, but they may still have spoken about immunity more vaguely, and the need to avoid a winter wave.
Its also certainly true that 'turning measures on and off repeatedly' was on their mind for plan B, because the likes of Imperial College did subsequently explore that possibility when looking at alternative options, talking about having trigger points for reactivating measures as infections rose, and a long cycle of mini-waves. This wasnt really considered desirable for all sorts of reasons including economic ones, so over time we ended up with all the local restrictions and pinning hopes on mass testing etc etc.
Anyway the reason I am explaining this now is to do with the fact that I think something has not really been drawn attention to when it comes to the 'plan B whiteboard photo' that Cummings tweeted the other day.
So two of the curves in that graph are to do with the original thinking - the extremely high peak wave if nothing was done, and the somewhat 'pushed down and stretched out' peak that they were aiming for with original herd immunity plan. And then there is the original possible plan B, the wiggly line where we end up in a cycle of mini waves that dont exceed NHS etc capacity.
But whats this wording attached to the plan B wiggly line? Oh look, it says 'Roughly same number infected but no collapse'. Well roughly same number infected implies same expectations of herd immunity! So attempts to attach a desire for herd immunity as the endgame were not just a feature of plan A, but also at least this initial stab at plan B!