I looked up the study - the model itself is valid BUT there are 2 significant gaps - openly disclosed (the authors also openly invite others to build on their model), which is good.  But the gaps mean their current result it's not valuable to our current Omicron experience: 1) they assumed only a small faction of the unvaccinated had been previously infected (so they were modelling virus naïve people), we're rapidly approaching a moment where most Canadians will have been infected; and, 2) they didn't model waning immunity for the vaccinated, which is a very real factor.