  We study the effects of physical distancing measures for the spread of
COVID-19 in regional areas within British Columbia, using the reported cases of
the five provincial Health Authorities. Building on the Bayesian
epidemiological model of Anderson et al. (2020), we propose a hierarchical
regional Bayesian model with time-varying regional parameters between March to
December of 2020. In the absence of COVID-19 variants and vaccinations during
this period, we examine the regionalized basic reproduction number, modelled
prevalence, relative reduction in contact due to physical distancing, and
proportion of anticipated cases that have been tested and reported. We observe
significant differences between the regional and provincial-wide models and
demonstrate the hierarchical regional model can better estimate regional
prevalence, especially in rural regions. These results indicate that it can be
useful to apply similar regional models to other parts of Canada or other
countries.
