A new COVID-19 subvariant called HV.1 is gaining traction across Canada, but whether or not it is more contagious than past variants remains to be seen, according to health experts.
HV.1, a subvariant of Omicron, is one of the only lineage groups showing consistent growth in the country, according to Health Canada.
Since August, the subvariant has grown from 2.1 per cent of reported cases to 34.4 per cent as of Oct. 29, Health Canada stated on its website. It also has overtaken other variants that were more dominant in the late spring and summer, such as XBB 1.16 (nicknamed the Arcturus variant).
“It’s here,” infectious diseases specialist Dr. Isaac Bogoch told Global News. “If you look at the most recent genomic studies from Ontario it is the most prevalent lineage. And that was at the tail end of October. So by now, it’s much more than that.”
In Ontario, HV.1 was the most prevalent lineage (23.5 per cent) from Oct. 15 to Oct. 21. Public Health Ontario said it is projected to increase to 43.0 per cent by Nov. 8.
Although HV.1 is gaining traction, Health Canada said as of Nov. 7, indicators of COVID-19 activity levels are moderate to low across the country, “with most observing stable to decreasing trends.” COVID-19 activity levels are the highest in Ontario.
Of all of the prevalent COVID-19 strains in Canada, sublineages of XBB (Omicron) made up 94 per cent of sequences in the past month, Health Canada said. This included HV.1.
As HV.1 spreads, health experts like Bogoch are cautioning that it may still be too early to determine if it’s more contagious.
However, according to Bogoch, people can expect more of the same, drawing parallels to the experiences of previous winters.
“We’ve been through this many times now,” Bogoch said. “If people want to know what this winter’s COVID situation is going to look like you only need to look as far as last winter. You don’t have to look as far back as the awful winters of 2020 and 2021, because we’re not going to have an event like that.”
HV.1 is another Omicron XBB variant that has descended from EG.5, according to Health Canada.
The subvariant’s ability to potentially evade people’s immunity may explain its surge in numbers, though Bogoch said it likely isn’t more transmissible than other variants.
“When something represents over 25 per cent of all your cases, you would see if this was vastly different from a clinical standpoint. We would likely have seen it by now, not just in Ontario but elsewhere in the world,” he said.
Currently, Canada labels any descendent of Omicron as a “variant of interest,” unless otherwise indicated.
According to the website, a variant of interest has the potential to replace the current dominant circulating lineage but the impact on population-level outcomes is either unknown or not expected to be meaningfully different than current lineages.
The symptoms of HV.1 closely mirror those of previous variants, such as general malaise, fatigue, body aches, fever, cough and a runny nose. In more severe cases, people may experience shortness of breath, potentially leading to hospitalization, Bogoch said.
He added that it’s important to remember that irrespective of the strain, seniors and those with compromised immune systems are at an elevated risk and more susceptible to this infection.
One symptom that seems to be less prevalent than before is the loss of smell or taste, explained Dr. Brian Conway, medical director of the Vancouver Infectious Disease Centre.
“Early in COVID, people would lose their sense of taste, their sense of smell. We’re not seeing that so much anymore. And it may well be that because you have background immunity to COVID, the symptom has been extinguished,” he said.
Conway also mentioned that while it’s “not terribly” likely for the HV.1 strain to introduce an entirely new set of symptoms unexpectedly, he cautioned against absolute certainty, noting that it’s still a novel virus.
The new variants that have popped up, such as HV.1., are all related to Omicron, Conway said.
“We haven’t changed Greek letters and we haven’t changed families,” he said. “Getting this XBB shot that’s out there that’s directed against some of the older Omicron variants, but it’s still an Omicron vaccine, will probably boost immunity in the majority of people, prevent severe disease and quite significantly reduce community-based transmission.”
Conway highlighted the significance of “booking your shot,” emphasizing that vaccination is the key to effectively addressing emerging viruses.
“We can expect this vaccine to reduce the risk of more severe manifestations of the virus and reduce the risk of hospitalization and death, especially in those who are most vulnerable,” he said.
Regions in Canada may have levelled out or even declined in COVID-19 cases, Bogoch said, but because it’s only mid-November, “we’ve got a lot of time ahead of us.”
“We will see COVID wax and wane and probably also have a rise in the spring as we’ve had in the last few years as well,” he said, adding this is why it’s never too late to get your updated COVID-19 vaccine.