danieldwilliam (![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
danieldwilliam) wrote2020-04-16 01:00 pm
danieldwilliam) wrote2020-04-16 01:00 pm
Entry tags:
On Exit Strategies from Quarantine
Again a post mostly to test my logic. I don’t think I’m right, I’m pretty sure I’m wrong, what I’m interested in is how I’m wrong. I do not think that the UK has a clear idea of how it will move from economically damaging restrictions to a new normal, or if it does, it is either failing to deliver that plan or the plan is grim.
I’ve been thinking about what is called as an exit strategy. By which people mean the process whereby we change from the current quarantine to “something else”. I’m not sure that calling it an exit strategy is helpful. I prefer to think of it as part of a process of reaching an accommodation with a new virus. Nomenclature aside, here’s where I think we are.
I think we are about in the middle of Stage A in what I think will be a four-stage process with Stage D being, we have reached an accommodation with a new virus.
Stage D could take one of several forms and the form it takes I think depends on four variables.
1) Whether we are able to generate persistent immunity to the virus most of the time for most people; a vaccine or acquired immunity for a period of a few years not months.
2) Whether the lethality remains at 1%, spiking to 5% in extremis, or whether a combination of the virus mutating to a less lethal strain and us developing or finding effective treatments reduces that significantly,
3) how able we are (and who the “we” is here is interesting) to take part in economic activity during a time of viral outbreak, does working from home, testing regimes, topical hygiene and good PPE mean that most economic activity can continue with little additional danger or not?
4) the public’s tolerance for restrictions on personal freedoms and the social and economic impact they will have on them personally and on the community more widely.
Stage A, I think, is a period of close control and restriction on personal movement. The aim is to contain the outbreak so that is manageable. By manageable I mean two things, one that the number of cases in any given week is less than the capacity of the health service to give them the best technically available care and two that we delay people getting ill in to the future when we hopefully will have more health care capacity, probably better treatments and perhaps a vaccine which will prevent them catching the disease at all. And that we have some meaningful choices about our reaction. Ideally, we would irradiate COVID-19 but I don’t think we are prepared to do that. So, for Stage A, we mostly stay restricted to our homes. Many businesses are closed, most social activities curtailed, many wages are supported by state subsidy (a form of redistribution using fiat money and future inflation instead of rationing).
Stage D might have 3 broad forms.
Form 1) A good accommodation: - If we have good immunity, good treatments, lower lethality and a good ability to work during a flare ups our accommodation is just to get on with things and COVID-19 starts to look like one of the periodic nasty flus we have learned to live with. People die of it in increased numbers every five years or so, and we, as a society get okay with that. There are two forms to this, one where working from home is the biggest part of it, another where vaccines and treatment are the bigger part of it. But it looks and feels a lot like the recent past did. Fundamentally, we have the virus under control.
Form 2) A bad accommodation which we let happen to the unfortunate:- we don’t manage to reduce the impact of the virus on people, we don’t develop good treatments, we don’t develop good immunity and keeping the economy going is hard, too hard. So we decide to let the chips fall where they may. Our accommodation with the virus is that we allow it to move amongst us and kill lots of people. Mostly elderly and sick people. Often not. Our accommodation with the virus is to become callous and fatalistic.
Form 3) A bad accommodation which we share:- we don’t manage to reduce the impact of the virus on people, but we decide not to let it kill lots of people so we keep pretty strict social distancing in place. At the first hint of a regional outbreak we close schools, pubs and offices. Nobody ever shakes hands again. Old people’s homes are maximum security enclosures. Testing and contact tracing are ubiquitous and the state knows where you are and what your body temperature is most of the time.
My money is on Form 1 being the likely outcome, followed by Form 2 if we can’t get to Form 1 within 2 years.
Let’s assume that we are heading towards Stage D Form 1.
To get there we have to pass through Stages B and C.
I think we are perhaps not quite half-way through Stage A. Current total UK deaths are about 15,000, implying about 2-3million people will have had the disease about 14 days ago. Perhaps an additional 2 million since the beginning of April for a total number of people with at least some form of immunity of about 4-5 million. Less than 10% of the population and far short of the 1/3 immune people in a population needed to naturally slow the spread of the virus or the 2/3rds to 4/5th required to naturally halt it. Assume that we remain in close quarantine for another 6 weeks, with an infection rate of approximately 1 and a cycle of 2 weeks. Then by the end of May we will have approximately 10-12 million people with some form of immunity.
My understanding of the science and medical ethics is that we are about 18 months away from having an approved vaccine which is provably not worse than the catching COVID-19. (And we probably will need to have some conversation about who gets the vaccine and what the strategy for the vaccine is.)
Stage B is some sort of managed reduction in the restrictions on personal freedom and economic activity. There is, somewhere, in theory, a ranked list, of the measures that can be put in place, the beneficial impact those measures have on the spread of the virus and their cost in terms of economic damage and restrictions on personal freedom. This list is political. It is political because the value of the cost of each measure kept in place is a political one. Pretending it is the purview of “the science” or epidemiologists alone is a cowardly vacation of responsibility.
Stage B is I think moving us towards one of two strategies to be followed in Stage C. It is a period of experimenting with different tactics for Stage C. An increase in capacity and capability. A reduction in restrictions. We may cycle between something that looks like Stage A and something that looks like Stage B, on a national or regional basis a few times.
Stage C is a longer term, more steady state set of restrictions which we are prepared to accept whilst we move towards the Stage D. Hopefully Stage D, Form 1. One version of Stage C is a low tolerance of the virus and the other is a steady-state of tolerance for the virus in the interim. Stage C Form 1 looks like what they are trying in South Korea and Germany. Lots of testing, tracking, tracing, personal isolation if you are a suspected case. Trying to keep the numbers of active cases in the thousands or tens of thousands, rather than the hundreds of thousands. We trade large numbers of people having relatively large amounts of freedom for small numbers of people at any one time having very, very restricted lives, at random and lots of public health officials running around swabbing people and taking their temperature and ordering them about. And we do this for a year or more. Stage C Form 2 looks like it would have wider, more even restrictions and we accept that hundreds of thousands of people will be infected each week and that for every 100,000 people infected, 1,000 a will die and again we do this for a year or more. In some ways, given perfect foresight your choice of Stage C strategy would depend on whether you thought we were going to end up with a low lethality virus which we can work around or a high lethality virus that we accept as a horrible but inevitable part of life in the 21st Century and also , if you think a good vaccine is 12-18 months away or 5 years or never coming. The question if you are looking at Stage C Form 1 is can you chase coronavirus around the UK for a period of ranging in duration from 2 years to forever in order to prevents hundreds of thousands of deaths, and are you prepared to do so.
So what does Stage B look like and when should we expect to see it start. I think that depends on what strategy is being pursued in Stage C. If our strategy in Stage C is Form 2, to let the virus slowly circulate in the population then we would expect to see a gradual easing of restrictions, followed by a gradual increase in the number of cases (and deaths), then some increased restrictions, reductions in the number of cases (and deaths). These re-imposed restrictions would probably be regional rather than national. Over some months we find an equilibrium where the rate of onwards infection is on average 1. So pubs stay closed for months, school re-open in September. Retail shops re-open with restrictions on the number of patrons in a few months’ time. Furloughing at the expense of future tax payers is phased out over six months.
Stage B, if we are moving to Stage C Form 1 looks like a huge increase in the testing regime. Several hundred thousand antigen tests a week plus many hundreds of thousands of antibody post-hoc tests. PPE issued in bulk to anyone who goes anywhere near the public. Mandatory mask wearing in public. Powers to enact and support very specific school and business closures. Mandatory close quarantine of anyone who is suspected of coming in to contact with the virus. The development of immunity passports.
And this I think is where the problem lies. I don’t see much evidence that the UK is successfully moving to a Stage B that leads to a Stage C Form 1. We are currently averaging about 12,000 antigen tests a day. Our target is 100,000 a day by the end of April. 100,000 tests a day is not enough. With 500,000 front line NHS staff, 100,000 tests a day cycles through the NHS staff most affected once a week. If you want to test all NHS front line staff and all supermarket staff and bus drivers, then 100,000 test cycles through the candidate population once a month or less. To achieve a target of 100,000 we need a daily increase in the number of tests conducted of 5,000. Every day, 5,000 more tests than yesterday. We should be seeing PPE rolling out of factories to NHS staff and supermarket staff and then to the general public. We are not.
So either we failing to achieve the build up to Stage C Form 1 (which implies a much longer period in Stage A and longer period of Stage B) or we are planning on Stage C Form 2 (which implies one to two thousand deaths a week until there is a vaccine.)
So my logic chain is this. At some point we must reach an accommodation with the new virus, either with an effective basket of prevention, cure and mitigation, or by becoming fatalistic about the deaths it causes. To get from where we are now, under national house arrest to there we are either putting lots and lots of effort in to containing the virus to as small a fraction of the population as we can or we restrict ourselves to merely keeping it under some form of control. If we were well on the path towards successfully restricting the virus to hundreds, rather than hundreds of thousands of new cases a week we would see it. So either we are not close to achieving that goal (prepare to be under house arrest for an another month or two longer than you already through) or we are aiming to trade looser restrictions sooner for thousands of deaths (prepare yourself, firstly for the news to tell you that 500-1,000 people are dying a day, and then prepare yourself for you not paying attention to that number any longer.)
What have I missed? Where am I wrong?
Re: Testing Capacity.
Lots of relatively small labs, e.g. at universities without a Very Large Medical School, have been offering test processing capacity and not always having it accepted; we're talking facilities with a capacity in the low hundreds a day (most of which don't have the staff to run at max effort). I've been assuming this is because the logistical effort of running samples around the country by the dozen isn't worthwhile; sooner or later, somewhere in Stage B or C, we must move to a less centralised model of testing and that's where those come in.
The NHS's official centralised testing capacity isn't being quite fully used at the moment, I think that is a very-short-term problem whilst they work out where the most impactful place to use a few thousand extra tests a day this week and next would be. I reckon the announcement yesterday about testing everyone being discharged from hospital to adult social care and ramping up testing in care homes is the answer to that question.
I don't know why the government isn't announcing new lab space coming on stream. I know it is happening to some extent and I'd have thought it was a good-news story. Possibly just because announcing such detail would make it clear they'll continue missing self-imposed targets?
Re: Testing Capacity.
I'm personally not all that fussed if we have 100,000 tests by the end of April or the first week of May (much as I personally would like to see Hancock forced to resign). The earlier the better obviously, but a week doesn't seem a material difference on a national scale.
I take your point on the logistics of small scale labs being challenging and I do see how that would not play well with a situation where the next thing we need to do necessarily involves thousands of additional tests not hundreds.
Re: Testing Capacity.