Our federal and provincial governments’ laying-down-of-tools over the holiday season with respect to statistical reporting on COVID and other currently-circulating respiratory viruses makes it impossible to reliably assess current risk factors. As just one example, the Globe and Mail reported on Wednesday that the lack of public data on child flu trends leaves doctors “flying blind”.
That uncertainty is reflected in our current composite chart which, at face value, presents a mixed picture. Municipal wastewater COVID PCR test results, normally the most timely indicator of infection levels, shows a continued acceleration of the current viral surge, but that data only goes to December 16. Slightly more recent test results from the minority of Ontarians still eligible for definitive PCR testing and COVID-related hospitalization across Canada, if taken at face value, both suggest that the surge has peaked and is levelling off at high values. However, those data points are always revised upwards as late reports are included, and such delays will likely prove to be even more significant for the holiday period. We’ll have to wait at least another week before a more accurate picture emerges.
While current Canadian data on COVID variants is likewise out of date, the most recent estimates from the US Centers for Disease Control show the most rapid rate of change in the pandemic to date. The blue bar in the current chart demonstrates the incredible speed at which the new JN.1 variant has skyrocketed to dominance. For most of the past year, the XBB lineage of subvariants accounted for essentially all new infections. JN.1, a much-mutated descendant of the BA.2 lineage, has over the past 8 weeks shot up from only 7% of new US cases to almost 62%. At this point in the pandemic, most people have reasonable immunity to infection gained from some combination of vaccination and prior COVID infection. In that environment, any new variant rising to dominance is almost by definition more adept than any of its current competitors at evading that immunity. Today, JN.1 is the obvious winner. However, it will undoubtedly spawn new subvariants which are even more effective in that regard.