Graham Medley – A rambling mind

Reflecting on the UK’s First Coronavirus Lockdown: Five Years Later

Chart 6 UK cases reported vs. model log y-axis 9th March lockdown, 84% effectiveness

This article presents two case number comparison charts for the 9th March and 23rd March 2020 UK Coronavirus lockdown dates. I had covered the deaths data in more detail in my previous post on this topic, and add that here too.

My Coronavirus model post-Pirola

Chart 318 for scenario UK_1445 with adult vaccinations, and vacs for 5-11 year-olds from 4th April 2022

I have updated my Coronavirus model to include an assessment of the potential impact of the new BA.2.86 Pirola variant. The model factors in age-group structures, transmission rates, vaccination phases, and non-pharmaceutical interventions. The model finds that despite reported decreases in Covid-19 cases in the UK, case recording has been high with recent data seeming erratic, with some inadequacy in the data reported by the Office for National Statistics (ONS) after it ceased its regular reporting. I source data from Worldometers, providing reliable Covid-19 figures. The accuracy of the model may be compromised by lower reliability of active case data.

My Coronavirus UK model outcomes as ONS reporting comes to an end

Chart 318 for scenario UK_1279 for June 11th 2023, showing ONS reported Active Cases at 9,614 cases. fmort Wuhan 2.1% and fmort Alpha 1.65%

The UK Office of National Statistics (ONS) had just announced that it was ceasing publication of the regular cases and deaths outcomes of the UK Covid-19 pandemic, as of 24th March 2023, and then revised all previously published Covid data. I was able to make global changes to most of my model history, by re-working some of the early Variant characteristics in the model. This post reports the outcomes of that work.

The Kraken Wakes* – Coronavirus

Chart 318 for scenario UK_1246 with adult vaccinations, and vacs for 5-11 year-olds from April 1st 2022. 24th February NPI reduction = -79.64%. Omicron BA.1 transmission k11 = 6, BA.2 k11 = 8, BA.4-5 transmission k11=11, Kraken XBB.1.5 transmission k11=15. All k2hl = 5.1. Omicron BA.1 var_eff = 25/50/70%. Omicron BA.2 var_eff = 70/85/95%. Omicron BA.4/5 var_eff = 25/50/70%. Kraken XBB.1.5 var_eff = 25/50/70%. Omicron BA.1 fSS=3% and fMORT=1.5%. Omicron BA.2 and BA.4-5 fSS=3% and fMORT=1.5%. Kraken XBB.1.5 fSS=3% and fMORT=1.5%. Model outcomes to December 3rd 2023. Reported active cases and deaths to 7th Feb 2023. Serious cases for 7 variants.

I have continued to improve and run my Coronavirus model daily. The code for the model is now at version 172, and I have added a dataset to represent the variant XBB.1.5, known informally as “Kraken”. The fit of the model to reported deaths is good. I explore in the article the behaviour of Modelled vs. Reported Active Cases.

Omicron BA.2, vaccination for 5-11 year-olds, and the honeymoon period – Coronavirus

Chart 318 for scenario UK_701 with adult vaccinations and 5-11 vacs from April 1st 2022. 17th May 1.8% ,19th July 1%, 1st Sep 2%, mean NPI relaxations and 30th Nov +2% and 10th Dec +3% additional NPIs. Omicron v4 transmission k11 = 6, BA.2 v5 k11 = 8, var_eff = 25/50/70%, fSS 7% and fmort 1.05%. Model outcomes to December 3rd 2023. Reported active cases and deaths to February 19th 2022. Serious cases for 5 variants.

I haven’t needed to make significant updates to my Coronavirus model for a while, because it has been working well.
The original Omicron variant morphed into the new BA.2 variant, and although it seems no more dangerous than its predecessor, it is thought to be between 33%-50% more transmissible. I have assumed the lower value of 33% more transmissive for this post.
I have added Omicron BA.2 as fifth variant v5 to my model, with 8 times the transmissibility of Delta, compared with the original Omicron variant v4 in the model, at 6 times the Delta transmission rate.

My model calculations for Coronavirus cases for an earlier UK lockdown

This post presents the two case number comparisons charts for the 9th March and 23rd March lockdown dates (I had covered the death data in more detail in my previous post on this topic).