Declining Omicron cases but increasing deaths

Something odd seems to be happening with the relationship between reported UK Covid-19 cases and deaths in the last few weeks, when deaths have been increasing somewhat more quickly than recently, but cases have declined steeply. My model charts seem to expose this oddity.

They think it’s all over – but it isn’t

In this article, I present a few variations of the current model to illustrate some outcomes depending on different assumptions about the current dominant variant, Omicron BA.2; they are fairly consistent in their forecasts over the 1400 day period of the model, from the outset in February 2020 to December 2023, and show that as NPIs are removed, vaccination is what keeps us safe.

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

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.

The pandemic situation in Europe

The pandemic situation in continental Europe has been worsening rapidly, and I felt that it I should update some country comparisons in a dedicated post.It confirms that the sourcing of data for a Coronavirus model of any given country is a very specific task nowadays, given the considerable differences in the underlying demographics, cultures, Government actions (NPIs) and public responses in the various countries.
This blog post isn’t looking at the modelling per se, but concentrates on the very different outcomes we are seeing across Europe, and looking at some of the reasons why.

Pandemic modelling review

Vaccination has somewhat stabilised the SARS-Cov-2 pandemic in the UK. I summarise the capabilities that I have found necessary and useful in modelling the behaviour of the pandemic; successive variants, different population age-groups, the effect of Government NPIs, and vaccinations.

Delta variant impact on June 21st easing – delay or reduce?

Having explored what pandemic advisers might be seeing and highlighting to decision-makers in Government, I run scenarios with different settings for the planned June 21st relaxation of lockdown, the last in the series of relaxations over the first half of 2021, following the January 3rd lockdown. These model scenarios show examples of what the relative consequences of the June 21st relaxation as planned, versus four other options:- cancellation of the June 21st step altogether, two different delays, of 28 and 56 days, and lastly a 50% reduction in the scope of the June 21st relaxation.

Tuning the age and vulnerability model

In my latest post on March 26th I described a new Coronavirus group model, based on work I had done as a UK case study in support of Prof. Alex de Visscher’s paper, in conjunction with Dr. Tom Sutton, on “Second-wave Dynamics of COVID-19: Impact of Behavioral Changes, Immunity Loss, New Strains, and Vaccination” which has now been published for peer review as a pre-print on Springer’s site at https://www.researchsquare.com/article/rs-195879/v1. I have now added the latest UK vaccination progress figures, and the UK Government’s announced intentions for the near future regarding Non Pharmaceutical Interventions (NPIs). I have also updated mortality and infection characteristics for the four different population groups in the model.

Age and vulnerability related Coronavirus modelling

In my most recent post on February 12th, I described modelling work I had done in support of Prof. Alex de Visscher’s paper, in conjunction with Dr. Tom Sutton, on “Second-wave Dynamics of COVID-19: Impact of Behavioral Changes, Immunity Loss, New Strains, and Vaccination” which has now been published for peer review as a pre-print on Springer’s site at https://www.researchsquare.com/article/rs-195879/v1. I have now added vaccination and multiple variants I had already added to our previous model into the new grouped population model, and this blog post reports on progress with that new model.

NPIs, variants and vaccine models

This paper reports some parametric Coronavirus model runs I have made that compare, in particular, how the UK vaccine programme allows some NPI relaxation compared with a case with no vaccination. The outcome is that the vaccine programme in the UK has the potential to reduce the imposition of NPIs on March 7th by about 15%, without costing lives, this being the next time we in the UK are due for a major NPI review, potentially involving the return of schools at around March 7th.