02 February 2021

We anxiously watch for the effects of the Vaccines

  We are very proud of and grateful for our dedicated NHS staff. They are working their socks off to get the two vaccines (Pfizer and AstraZenica) distributed where they will (a) save lives, and (b) bring down the number of circulating viruses.

        I have been following the numbers of new COVID-19 cases reported in the whole of the UK each day on the excellent government website. I plot the logarithm of that number against the day. In December 2020, under a confused and heterogenous tiered system, the virus continued to spread; logged data (pink symbols) rise more-or-less monotonically, with a doubling time of 16.3 days. After Christmas new lockdown was imposed. Since 5th January the logged data (blue symbols) fall more-or-less monotonically with a halving time of 16.3 days. (During the first lockdown, in May and June, the falling incidence showed a halving time of 19.8 days, so this January 2021 fall is marginally faster.)
        Vaccination started at 8th December 2020, but till this time (end January) it has been largely confined to the over 70 age group. It is clear that this group, selected as the most likely to die of COVID-19, are not the group most likely to be the main spreaders of the virus.  
The December data (pink squares) show a steady rise, doubling every 16.3 days (rather ignoring Boris’s lockdowns, letups, and tiers, but maybe showing a slight upward curve as the 'Kent' variant spread.).
        So far, the data for the whole of the UK from 5th January fit a fairly steady monotonic decay curve, t½≅16.3days. (See Fig. 1. Remember, I plot (on the vertical axis) log [base 10] of the number of new cases reported on each day relative to 1st Jan 2021 (shown on the horizontal axis). Blue diamonds are January data to 31st inclusive.) I am sure that everyone is hoping to see a distinct acceleration in the decline of these transmission numbers, but that is not yet visible. 


(The preference for ‘reporting cases' on Fridays is very pronounced — 8, 15, 22, 29 in Jan 2021.)

Of course, the over 70 age group are not the major spreaders, So let 
us look at the Logged (and smoothed) data for the number of deaths on 
each day in January. Unfortunately, there is no convincing sign yet of a 
decline in the daily death toll. The data show only a strong dependence 
on the day of the week. Throughout January, Mondays are good days, 
with 2-3 times fewer deaths than found on Wednedays.







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