COVID 19 Wave#3: Trends become clearer

Click for a larger image. Logarithmic graph showing positive caseshospital admissions and deaths since the start of the pandemic. The blue arrows show the dates of recent ‘opening’ events. The green dotted line shows an extrapolation from the first week of June. The purple area shows the period of the Euros finals.

Friends, I last wrote about the pandemic 11 days ago on July 27th. Then I said:

… [the] decline in daily cases is really welcome. However since I don’t know why it has happened I can’t really imagine what will happen next.

If I had to guess, I think I would expect the rapid decline to be temporary. I think daily cases  will fall to a still high level, perhaps 10,000 cases per day, but hopefully less.

And then I would expect daily cases to either increase again or decrease, but much more gradually. But that is just a guess.

So in the coming weeks I will be looking to see if the hospitalisations and deaths show the same peak in  cases, and then trying to discern the ongoing trend in cases.

Things have now become clearer, and the rapid decline in daily cases was indeed temporary and the timing indicates that it was associated with the Euro 2021 championship.

Click for a larger image. Logarithmic graph showing positive cases, since the start of 2021. The blue arrows show the dates of recent ‘opening’ events.  The green dotted lines show (a) an extrapolation from the first week of June, and (b) a guess for the ‘underlying’ spread showing the ‘Euros Effect’.

The peak in daily cases occurred on 21 July and daily hospital  admissions  peaked 10 days later on 31 July. This correlated peak in admissions indicates that the peak in cases was not a measurement effect but arose from a real increase in viral prevalence.

As I write (7 August) the number of deaths per day has not yet reached its peak but the 7-day retrospective average is currently 90 deaths per day.

Ratios

By looking at the data at the peaks (7-day retrospective averages) we can estimate how many cases result in hospital admissions and how many hospital admissions result in deaths.

  • Around 47,700 cases per day resulted in about 930 admissions to hospital per day i.e. a ratio of roughly 2%
  • Around 930 admissions resulted in at least 90 deaths per day i.e. a ratio of roughly 10%
  • So 47,700 cases per day results in at least 90 deaths per day i.e. a fatality ratio of roughly 0.2%

These figures are much lower than earlier in the pandemic, but they are still – in my opinion – worryingly high. For comparison, in the UK we normally expect about 1700 deaths per day from ‘non-pandemical’ causes.

Ongoing Trends

Recently daily cases have fallen to around 27,000 cases per day – a very high level by either a historical or an international comparison.

Worryingly daily cases still appear to be slowly increasing. Measures to restrict viral spread appear to be ad hoc at best and so we might reasonably expect Wave#3 to continue for several weeks – or even months – at a similar level.

Based on the ratios above, 27,000 cases per day will result in roughly 55 deaths per day or around 1600 deaths per month.

27,000 cases day probably corresponds to very roughly 1 million infections per month which is similar to the rate at which first doses of vaccine are being administered.

Click for a larger image. The progress of vaccination amongst the UK population. The left-hand axis shows the population in millions and the right-hand axis shows the fraction of the entire population – not just adults. The dark blue line shows first doses and the light blue line shows second doses.

What do I think about this?

I don’t know!

I hate to say it – and readers in New Zealand and Australia and South Korea and Taiwan may find this extraordinary – but in the UK at the moment, this level of infection and death is ‘politically acceptable’.

The alternative – re-imposing restrictions and re-doubling vaccination efforts – is not being considered.

  • If we are lucky, then the death rate will remain at 50 or so people per day for just a month or two – perhaps increasing when schools and universities restart – and then slowly reducing as the long-sought ‘herd immunity’ is achieved. The death toll from Wave#3 might be below 10,000.
  • If we are unlucky, then this death rate will continue for several months, and the widespread prevalence amongst the several million immunocompromised people might result in a new variant against which vaccines are not as effective.

This is not the policy I would have chosen – I would have been less inclined to rely on ‘luck’ as an ally. But given where we are, if the death rates and hospitalisations rates remain low enough then I can’t see this policy being changed.

On the plus side – for the non-immunocompromised – a reasonably normal life is possible.

In contrast with the UK’s ‘Total COVID’ strategy, countries which have adopted a zero-COVID strategy – such as China, New Zealand or Australia – will have to retain strict border controls until their populations are fully vaccinated.

But since no border controls are perfect, they will probably have to periodically impose lockdowns as new infections are imported: And in democracies, there is a limit to the amount of restrictions citizens are prepared to accept – and colloquially – many people seem to feel we are close to that limit. For example restrictions on Australians leaving Australia seem extraordinary!

Over the coming year or so, COVID might become endemic in the UK, and so there might not be too many restrictions for entering the UK – but countries worldwide might retain especially tight restrictions for passengers from the UK.

As many people have said until COVID vaccination becomes available world-wide, COVID will remain a threat everywhere in one way or another.

Good luck wherever you are.

 

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