We are aware that the rates of cases and deaths in the USA have increased steeply recently, and it seems that the natural public relaxation in precautions against Covid-19 for the Thanksgiving holiday period have exacerbated this. I have run my model with reductions to the USA intervention effectiveness during the Thanksgiving period (reflecting the increase in travel and social interactions in the USA) followed by reintroduction of the intervention effectiveness afterwards, to see the effect on the immediate projections. I have then applied similar changes to my UK models, to anticipate what the possible effect of such relaxations over the UK festive period might be. This is very much a sensitivity test of some scenarios, not a forecast.
Tag Archives: modelling
The end of the beginning*
Now that it seems clear that a vaccination programme in the UK might start as early as next week, I have re-run my Covid-19 vaccination model for the UK, updating the November 25th scenarios (which begin on January 1st 2021) to reflect some potential UK outcomes.
Vaccine, vaccine, vaccine, vaciiiine,…(don’t refuse it, just because you can)
In the news today, I read that Dolly Parton had given $1,000,000, through her Covid-19 Research Fund, to help fund the Moderna vaccine development. As The Times newspaper reported, this – erm – somewhat trumps the White House contribution to public safety. In her honour, Ryan Cordell composed and performed this ditty. The timing neatly coincides with the work I have been doing to incorporate vaccination into my Coronavirus model, and to that end I have been researching ways of modelling vaccination. I have made some appropriate changes, and run some model options for different vaccine efficacy; vaccinations per day; and date of starting the vaccination programme.
Adaptive triggering and the epidemic life-cycle
Introduction In my last post on October 21st, looking at the potential for an exit from the epidemic, I described a cyclical version of the modelling of the epidemic in the UK, reflecting outputs from Imperial College and Harvard earlier this year, which postulated a continuing cycle of partial lockdowns, easing of restrictions and upsurgesContinue reading “Adaptive triggering and the epidemic life-cycle”
Recent events and Coronavirus model update
Many countries, including the UK, are experiencing a resurgence of Covid-19 cases recently, although, thankfully, with a much lower death rate. I have run several iterations of my model in the meantime, introducing several lockdown adjustment points, since my last blog post, as the situation has developed. The key feature is the sharp rise cases, and to a lesser extent, deaths, around the time of the lockdown easing in the summer. I have applied a 10% increase in current intervention effectiveness on October 19th (although there are some differences in the half-term dates across the UK), followed by a partial relaxation after 2 weeks, -5%, reducing the circuit-breaker measure by half – so not back to the level we are at currently. The effect of that change is shown in the final chart in the blog post.
A brief look at model sensitivities to lockdown easing as we prepare for winter
The UK Government has just announced some reversals of the current lockdown easing, and so before I model the additional interventions announced today, I want to illustrate quickly the behaviour of the model in response to changing the effectiveness of current interventions, refecting the easings that have already been made, and also to highlight the sensitivity of the forecasts of case and death rates to the influence of lockdown effectiveness.
SARS-Cov-2 modelling situation report
As we start September, the UK situation regarding Covid-19 cases and deaths has changed somewhat.
Since the UK Government re-assessed the way deaths data is collected and reported, the reported daily deaths resulting from Covid-19 infections have (thankfully) reduced to a very low level.
Cases, however, have started to rise again, although for a number of reasons the impact on deaths has been less than before. I have integrated the real world reported data with my model data to assess what is happening.
Model update following UK revision of Covid-19 deaths reporting
On August 12th, the UK Government revised their counting methodology and reporting of deaths from Covid-19, bringing Public Health England’s reporting into line with that from the other home countries, Wales, Northern Ireland and Scotland. I have re-calibrated and re-forecast my model to adapt to this new basis.
Model updates for UK lockdown easing points
As I reported in my previous post on 31st July, the model I use, originally authored by Prof. Alex de Visscher at Concordia University on Montreal, and described here, was to be updated to handle several phases of lockdown easing, and I’m glad to say that is now done. Alex has been kind enough already to adopt a method I had been considering, of introducing an array of dates and intervention effectiveness parameters, and I have been able to add the recent UK Government relaxation dates, and the estimated effectiveness of each into a new model code. I have run two sets of easing parameters as a sensitivity test.
The effect of lockdown easing in the UK
As reported in my previous post, there has been a gradual reduction in the rate of decline of cases and deaths in the UK relative to my model forecasts. This decline had already been noted, as I reported before, by The Office for National Statistics and their research partners, the University of Oxford, and reported on the ONS website.
I had adjusted the original lockdown effectiveness in my model (from 23rd March) to reflect this emerging change, but as the model had been predicting correct behaviour up until mid to late May, I will present here the original model forecasts compared to the current reported deaths trend.
A rambling mind 