Covid-19 Mortality Rates in Northamptonshire UK: Initial Sub-regional Comparisons and Provisional SEIR model of First Wave Disease Spread

We analysed mortality rates in a non-metropolitan UK subregion (Northamptonshire) using statistically-weighted data fitted to the start of the
epidemic to quantify SARS-CoV-2 disease fatalities at sub 1,000,000 population levels. Using parameter estimates derived from the recorded
mortality data, a numerical (SEIR) model was developed to predict the spread of Covid-19 sub regionally. Model outputs, including analysis of
transmission rates and the basic reproduction number, suggest national lockdown flattened the curve and reduced potential deaths by up to 4000
locally. The modelled number of infected and recovered individuals is higher than official estimates, and a revised form of the theoretical critical
population fraction requiring immunisation is derived. Combining published (sub-regional) mortality rate data with deterministic models on
disease spread has the potential to help public health practitioners refine bespoke mitigation plans guided by local population demographics.