Looking at the shape of those graphs for admissions (thanks
elbows ) - To my eyes, the climb before and after the November restrictions [not-quite-a-lockdown] is at a very similar angle. If anything, the post November climb is steeper in some areas.
I agree, that period in November really was a case of "too little, too late" and wasn't applied for anything like long enough. And then we had to save christmas / new year ... and now we've got several new variants impacting the situation.
The incredibly steep trajectory see in some regions after the first week in December is a main reason they searched for an explanation and found one with the new variant. Especially because the timing of that and when they saw rises in other data such as cases, indicated that the rise in infections began whilst the November measures were still in effect, so it wasnt being driven only by the shitty tiers they came up with once the November measures came to an end.
I'm pretty sure that modelling would not have predicted such an immediate and steep climb in rates in regions like London, the South Easy and the East of England, after the brakes were taken off. So whatever they thought they were playing at was probably thwarted by that. Its possible they thought that the November measures had bought them a December in which they could carry on with their original Christmas plans. And then things would get real bad in January and they would do a lockdown then, once the 'business' and politics of Christmas were over.
In my mind there are several properties of the new variant that could be responsible in theory, and also a number of other potential explanations.
For example in regards the new variant, modelling was done to see if the increases seen fitted best with increased transmissibility, or an increased ability ot defeat immune systems that had been primed by past infection with an earlier strain of the pandemic virus. The model involving increased transmissibility seemed to fit best, and they had some other evidence to do with viral load and testing of new variant samples. I wouldnt call it a solid conclusion, its the possibility they considered most likely. If their thoughts on this have evolved significantly since, I havent found out about it yet, although I believe there was a somewhat lower estimate of increased transmissibility doing the rounds recently which I didnt have time to look at. And I didnt get the regional new variant data I was expecting today.
In terms of other explanations beyond the new variant or the obvious effects of releasing the brakes too soon, I've got a few thoughts but I havent really found any expert stuff to backup where my thoughts were going. So its just a collection of possibilities I have deduced but that I dont consider ripe enough to go on about much yet.
But for example, we have the topic came up here recently of what role the number of susceptible people in a population has on epidemic waves and the modelling. And I found some quote about what difference an increase in people whove now had the disease can have on the R rate, especially once R is around one. They were looking at how this picture improves over time as more people get infected, influencing R in a downwards direction. And there was also stuff about a lot of the people whose occupations etc meant they were most at risk of infection in the first wave were the same people exposed most in the second wave, and the role that existing immunity the second time around could play in robbing the virus of so much 'front line fuel' in subsequent waves. I wondered what happens when we apply these same principals in reverse, to selected sub-populations in certain scenarios.
Lets say for example you have a population that were not so much in the front lines for the first wave, because their movements and the institutional setting of interest where they mix were limited by the original lockdown. But then when dealing with the second wave, you dont lock them down when taking a national response in November. Are they not a population that then becomes a large, relatively fresh new target for the virus? The virus spreads through human networks, and here is a network that was largely disabled the first time but is in full flow this time (well, in November and December, not now). Would it be reasonable to place schools in that category? Hmmmmm. Im not an epidemiologist so I dont know if I joined the right dots on that one.
Obviously, we'll have to wait and see when the current "stay at home" rules and the vaccinations start to bite into the cases, admissions and death rates.
Hopefully, they will already be starting to have affects ...
Combination of factors that happened a while ago would be expected to influence the picture we currently see, which includes something with hospital admissions that I dont quite want to call a plateau yet, but is certainly a trajectory change.
Its a combination of tier changes, tier 4 coming in, tier 4 expanding, and then schools and workplaces being closed for Christmas holidays, and then finally the current lockdown. Versus the chains of infection that were already in motion, and whatever risky stuff some people did over Christmas, and then whatever the bad effects are from how many people are still working and doing other things during this lockdown. And stuff linked to weather and behaviours and the extent to which full hospitals are increasing transmission, the extent to which the virus is getting into care homes etc.
I wont be surprised if the picture via data remains as messy as my attempts to describe the factors involved for a while. And we know the deaths numbers will keep going up for longer than the hospital data. It sort of does my head in that at the same stage like this last week where I have been able to make comments about tentative good signs, there is not currently a clear end in sight in terms of reporting ever worse death data.