While still conveying mixed messages, the principal statistical indicators upon which we rely to gauge pandemic severity suggest that the surge of new COVID infections is plateauing at high levels as opposed to continuing the seasonal Fall surge.

PCR testing of municipal wastewater is normally the best leading indicator of infection rates. As you can see in this week’s composite chart, the most recent Ontario COVID viral counts remain well above their December 2022 peak, but their rise is showing signs of slightly moderating. The sharp rise in positivity rates for PCR tests among the minority of Ontarians, while still very high, has at least stabilized in recent weeks, as have both Canadian and Ontario COVID hospitalization and ICU admission rates. 

This has been the second week of the biweekly forecast from COVID-19 Resources Canada, which we reported last week as having estimated that one in every 41 Ontarians is currently infected with COVID and therefore infectious. Their more detailed charts show the continuing very high infection rates having levelled off starting in mid-October. 

Turning to currently-spreading variants, the latest US CDC data indicate a surprising development in the evolution of ever-more transmissible and immune-evading COVID strains. Last week, we reported that BA.2.86, a non-XBB variant with 34 mutations in its spike protein, was by far the fastest-growing among the current zoo of new strains and could easily challenge to current dominance of the EG.5 family. At first glance, it appeared to have taken a sudden drop in “market share” over the past week. It turns out, however, that BA.2.86 had already spawned a new subvariant, JN.1, with even more mutations that is radically outcompeting its parent. Already accounting for more than 21% of new US cases, JN.1 is second in the US CDC rankings, having become an astonishing 54 times more prevalent over the past eight weeks. It is very likely to become fully dominant within a matter of weeks.