It is a simple fact that from the start, if like Sweden (link) we had protected the old and vulnerable then, then even under the worst case scenario, under 50s households could have continued with their normal life with minimum impact on the NHS which could have coped even without the additional resources that were made availabe. But recently more and more evidence has been coming out (link)(link)(link) that we have massively over estimated the impact of CV19 because of the very high number of people who get it without serious symptoms, leading us to believe the total number of deaths would be about 5x the actual number. This now means that the NHS could have just coped if we had only strictly isolated those over 70 and the vulnerable.

Please sign the petitions to support this plan:
Change.org
UK gov (still to be approved)

For further discussion on the underestimation of R0 see: "The Failure of R0"

The problem in the UK is that we allowed the virus to spread to older people who are far more likely to end up in hospital and as a result we risked crashing the NHS. To understand this, here is a graph showing the number of deaths by age in Italy (yellow) as well as China (red).

 

It is very clear that in both countries the vast majority of deaths occurred in those over 60 and the level of deaths in under 40s is so small it cannot be distinguished from zero. If then we use this to estimate the effect on the health service it produces a graph as follows:

The dotted blue line shows the fraction of the population up to the specified age. The red line shows the estimated demand from CV19 of everyone up to that age. So for example 70% of the population are under 50 but that 70% create only about 10% of the demand on the NHS. In contrast, over 70s are about 10% of the population but create 50% of the demand.

What that means, is that if we could have totally isolated the over 70s, the demand would halve. Or to put it another way, we could have got through the crisis in half the time. If we could isolate everyone over 50, we could have got through the crisis in a tenth of the time - or without any lockdown. Below is a curve estimating hospital beds and intensive care beds required just for the under 50s.

The red line represents the total beds available before the crisis. As we can see the demand on NHS beds is minimal, and although a lot of Intensive care beds might be needed, the NHS could easily cope if only under 50s were exposed to CV19.

So, can we release under 50s now? The answer I believe is yes (if we stop under 50s households infecting older people) for the following reasons:

  1. The NHS could cope with under 50s if at the same time we have a very tight lock down of other age groups.
  2. Many younger people have already had the virus, the impact on the NHS is now even less
  3. The virus is known to predominantly affect people with underlying conditions. As such if we protect these individuals in the under 50s group, then the problems will be much less
  4. Even if the government told everyone that they could immediately return to normal, many people are now so scared of CV19 that they will not return to normal life.

Households versus Individuals

An important caveat, is that whilst the analysis is for individuals, we live as households and so that plan for coming out of lockdown must fit the way we live. Fortunately, the nature of human fertility and human nature, means that most people with school age children are under 50 except for a few in senior schools and men who married much younger women. Likewise, single adults either tend to be living on their own or with similar aged adults (except in special circumstances like prisons). So, for most reasonable purposes "families with school age children" are under 50. But to be sure we could say that "families with young children where no resident is over 50 and under 50s living on their own or where there are no over 50s" can return to normal life ... with the proviso that "normal" cannot include mixing with over 50s or those from households with over 50s.

Over 50s

Whilst there is no problem under 50s returning to normal life, things get more complex the older we get because the death rate is about 10x the average for under 50s for 50-60 year olds approaching 100x for the most elderly. Fortunately, the number of very elderly people is relatively small, with 10% over 70. The very elderly and those of other age groups who are most vulnerable to CV19 should be protected from the virus. To this end, they should be given all the necessary PPE and for example they must have priority for supermarket home delivery. The aim for them is to maintain a strict isolation until the virus has died out. At first this isolation must be compulsory, in order to permit younger people to pass through the epidemic without the beds being used by older people. But once younger people are through then we can advise older people to remain isolated, but they have a right to freedom.

So under 50s household return to normal life immediately. Over 70s are isolated until it is safe. This leaves the 50-70s.

Because of their higher risk, and therefore higher risk of inundating the health service there may have to be restrictions for this group for a short time. But after that we need people to decide which group they belong to. Whether they join normal society, albeit at the risk of contracting CV19, or whether they isolate until the virus dies out. What we cannot allow, is someone who has not had the virus to suddenly decide to re-enter society at the time the virus is dying out. Because if this happens in large numbers there could be another surge of infections, meaning that the over 70s may be in isolation for perhaps another month longer than need be. Nor can too many rejoin society if that risks over-whelming the health service. As such, we may have to stage the return of this group, but this will depend on what is happening in the NHS at the time.