As summer approaches and health measures for COVID-19 continue to weaken, experts say the increase in Omicron sub-variants could lead to a new surge in Canada.
Sub-variants of BA.4 and BA.5 feed the growing number of cases in the United States, Europe and elsewhere in the world. In Canada, both variants accounted for 3.9% and 6.5% of COVID-19 cases, respectively, according to samples collected during the week of 29 May. The cases of BA.2.12.1, another growing sub-option, also represent 40.5% of the cases.
At a media briefing on Friday, Canada’s Chief Medical Officer, Theresa Tam, noted the growth of these sub-options, saying they “demonstrated a growth advantage in additional immune escape” over previous options, citing declining immunity. against the vaccine and viral evolution.
“We do not expect our progress to be linear, so keeping ready for a potential resumption that could have a serious impact is our best asset,” Tam told reporters.
Toronto-based emergency room physician Dr. Kashif Pirzada says the increase in these subvariants shows how quickly the virus can mutate.
“It is evolving to beat our immunity and our vaccine, and it looks like we will be in a world where we have waves every two to three months,” he told CTV News Channel on Saturday. “The crazy thing is that immunity from a previous infection, even if you received Omicron during the January wave or last month – may not protect you from this option because it’s different enough that your immunity won’t be strong enough for it.”
In Portugal, where option BA.5 accounted for 87 percent of cases as of May 30, hospitalizations were increasing as a result. Last week, the Centers for Disease Control and Prevention announced that BA.4 and BA.5 now account for 8.3% and 13.3% of COVID-19 cases in the United States, respectively.
“If you look at countries like Portugal that got the BA.5 option … it’s one of the highest levels of vaccination in the world and you see a jump in hospitalizations there. So this may be a warning to us, “Pirzada said. “We hope that the summer time here and the schools that are open now will stop us from doing so badly, but that means we have to be careful.”
Dr. Zane Chagla, an associate professor at McMaster University in Hamilton, Ontario, and an infectious disease doctor at St. Joseph’s Healthcare Hamilton, says it’s not yet clear what will happen in Canada.
Portugal, for example, has seen a large wave of BA.4 and BA.5 cases, but had a relatively small number of BA.2 cases, similar to South Africa, he said in an email to CTVNews.ca on Sunday.
But Portugal is also seeing a “decent percentage” of re-infections, with the elderly appearing to be more likely to get sick, he said.
After taking about six weeks to reach its peak in Portugal, Chagla says another wave of Omicron cases could hit Canada over the next few weeks, with closed, high-capacity and poorly ventilated rooms at greater risk. transmission of COVID-19.
“At this point, people need to commit to what [they] Feel comfortable, but recognizing that the percentage of the community is increasing, so is the exposure in these settings, “Chagla said.” Masking with a well-placed mask … adds protection to some of these settings. “
He recommended that those at high risk of COVID-19 infection keep up with their vaccinations, including third and fourth doses. Canadians also need to know where and how to be tested if symptoms develop, as well as how to access treatments that are widely available in Canada and can reduce the risk of hospitalization associated with COVID-19.
Canada currently has a low rate of cases and hospitalizations, and Tam said the Canadian Public Health Agency feels “cautiously optimistic about the current trajectory.”
“If you compare where we are now with where we were, you know, a month and two months ago, we are doing much better,” infectious disease specialist Dr Isak Bogoc told CTV News on Friday.
However, Bogoch believes there could be a “summer blow in cases, depending on how this develops,” citing data on Ontario wastewater showing recent increases in SARS-CoV-2 concentrations.
“It shows a slight bump in the signal and I don’t think it’s just a flicker,” he said. “I think this is the real deal, because if you look at different areas of Ontario and it’s not geographically unique to one area. You see that signal in many geographic regions.”
With files from CTV National News correspondent in Toronto John Venavali-Rao
Ontario wastewater data show a recent increase in SARS-CoV-2 concentrations since early June. (Ontario Scientific Table)
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