Canada’s virus modelling has been largely accurate

OTTAWA — Coronavirus modelling from the Public Health Agency of Canada has a strong track record of predicting where the virus is going, a troublingly trend given the agency now predicts a potentially steep rise in cases.

By Sunday, Canada was predicted to have seen between 841,650 and 878,850 cases of coronavirus and recorded between 21,510 and 22,420 deaths, according to the latest modelling.

That modelling was almost certain to be right because, as of Friday, there were 858,217, cases and 21,865 deaths.

A review of the modelling numbers the Public Health Agency releases around every month shows its predictions have been within range of the actual results most of the time.

The agency's estimate for the number of cases on Jan. 24, missed the mark by about 5,000 cases as Canada recorded 747,383 cases, lower than the agency predicted, but a day or so later the pandemic reached that target.

Last September, the agency slightly underestimated how fast the virus would grow — it predicted a high of 155,795, while Canada actually saw 160,535.

The model has also twice slightly undercounted the number of deaths the country would see.

Outside of those estimates, the agency has accurately predicted where Canada would be each month since last June.

In addition to the estimates, the agency has also issued worst-case scenarios with each new modelling update. Those scenarios haven't come to pass, but experts say that's exactly what is supposed to happen.

Canada's new daily caseload has been falling since a Jan. 4 peak, but, with new variants and a lagging vaccine rollout, the agency fears the downward slope may not stay that way.