COVID-19 models at 26 April Ireland Italy and US

Our predictive models for Ireland, Italy and the US are stable and identical for each region, differing only in fitted parameter values (e.g. R0 and people movement versus time).  As the progress of COVID-19 is slowed by restrictions, the fitted parameter values for people movement have become more consistent from week to week.  Models with data to 26 April 2020 are available here as usual.
Good progress is being made and restrictions will be gradually loosened and occasionally re-tightened over the coming weeks and months, depending on trends in case numbers. 

Data for Ireland remains harder to interpret because of delayed testing results and some changes in the basis for reporting deaths this week.  A graph showing backdating of rest results was shared by the government on 23 April 2020 and we have used this to update the Ireland model; however there are spurious peaks (see below) and in addition, focused testing in care/nursing homes generated high case numbers this week that probably do not reflect a trend.  We therefore did not do a tight fit to the Ireland data.

Known case data for Ireland reported by the ECDC and a backdated version of the same information published on Thursday this week.  Both versions contain spurious trends that make direct use for parameter estimation difficult.

Approximate model fitted to backdated Ireland data indicates that the number of infectious in the first wave probably peaked around 1 April 2020.

Over the next weeks we will explore developing a more granular predictive model for the loosening of restrictions, especially focusing on the degree to which communities can return towards normality while those especially vulnerable remain protected.