A new sub-variant of Omicron, XBB.1.5, continues to gain a foothold in Quebec, with its weight in infections doubling every week. Good news, however: its presence in the northeastern United States, where it is now predominant, has not led to a marked increase in hospitalizations there.
First detected at the end of November, XBB.1.5 really began to take hold during the holiday season. Since Christmas, its weight in infections has doubled every week.
“This is what was also observed in the United States, where it was first observed,” says clinical specialist in medical biology at the Quebec Public Health Laboratory Inès Levade.
Cases due to XBB.1.5 represented 15.7% of new infections detected in Quebec in mid-January, the most recent data available. This is twice as much as the previous week (7.8%), when they themselves represented a marked increase (4.7%) compared to the previous seven days.
The XBB.1.5 sub-variant thus arrives in the wake of its cousin BQ.1.1, still to this day the most frequent in Quebec. During the holidays, it accounted for two-thirds of new infections. However, it has since declined, now representing 54% of cases.
The arrival of XBB.1.5 coincides with a resumption of the spread of COVID-19. The 582 new cases detected by PCR tests reported on Wednesday bring the daily average to 444. The downward trend observed since Christmas is thus slowed down and seems to want to start rising again.
As often since the start of the pandemic, the renewed spread seems to be starting among the youngest Quebecers. Data from the National Institute of Public Health of Quebec reveal a recent increase in cases among those under 50.
Unlike some of its predecessors, XBB.1.5 has a new mutation that allows it to better attach to cells, which explains its greater growth potential, explains Inès Levade.
However, its marked spread in the northeastern United States, where it is now the predominant variant with more than 90% of COVID-19 cases associated with it in New York State, has not been not translated by an “explosion of cases”, specifies the scientist.
“Hospitalizations are also decreasing in New York State,” she explains. “It serves as a compass” for what could happen in Quebec, adds Inès Levade.
As a matter of fact, despite the arrival of the new sub-variant, the trend in hospitalizations remains down in the province. On Wednesday, Quebec counted 1,476 people hospitalized who tested positive for the coronavirus, down 13% over one week. Of these, 457 patients had been hospitalized directly due to their COVID-19 infection, the others having been admitted for another reason.
The immunity acquired in the population since the start of the pandemic as well as the now widespread vaccination could explain the fact that the arrival of this new variant does not result in an increase in cases, believes the scientist.
The current situation therefore results in the presence of a “soup of variants” all different from each other, but without necessarily being more dangerous from a public health point of view.
But isn’t the presence of all these variants likely to result in the appearance of a mutation that could make one of them particularly dangerous? “It could happen and that’s why we maintain surveillance, to ensure that we detect it fairly quickly if it happens,” says Inès Levade.
The main danger now is that some of these variants are more resistant to the various COVID-19 treatments developed so far, which is bad news for immunosuppressed people who benefit from them.
“The variants currently do not seem to evolve towards increased dangerousness, but towards an immune escape which means that there is an increased risk of being infected a second time [par le même variant] “, describes the clinical specialist in medical biology.
The eight COVID-19-related deaths reported Wednesday bring the seven-day daily average to eight.