Canada is seeing an increase in several fast-spreading COVID-19 variants that have been fuelling new outbreaks in the United States and Europe, Canada’s top doctors said Friday.
The BA.4 and BA.5 strains of the virus, which are subvariants of Omicron, have been detected in Canada since May, and the BA.2.12 subvariant has been showing growth in the country since March.
On Friday, Canada’s chief public health officer, Dr. Theresa Tam, made note of the rise in the number of these cases in the country and said that these subvariants have “demonstrated a growth advantage and additional immune escape” over Omicron and other strains of the virus.
“COVID-19 has shown us over the past few years that there may be more surprises ahead,” Tam said during the briefing.
“The virus is still circulating in Canada and internationally, and factors such as viral evolution and waning immunity are anticipated to impact COVID-19 activity moving forward.”
The BA.4 and BA.5 subvariants are estimated to make up about 8.3 per cent and 13.3 per cent of the coronavirus variants in the United States as of June 11, the U.S. Centers for Disease Control and Prevention (CDC) reported earlier this week.
The two fast-spreading sublineages were added to the World Health Organization’s monitoring list in March and have also been designated as variants of concern in Europe.
The European Union’s disease prevention agency said on Monday the new subvariants are spreading more quickly than other variants, which could lead to more hospitalizations and deaths as they become dominant in the continent.
Portugal is also seeing a surge in new COVID-19 infections, the vast majority of which have been caused by the BA.5 variant. And both the BA.4 and BA.5 strains drove South Africa’s fifth COVID wave last month.
According to the latest Canadian data published online, the percentage of COVID-19 cases of variants identified as BA.4 and BA.5 rose to 7.6 per cent as of May 22, up from 2.1 per cent of cases during the week of May 15.
The BA.2.12.1, which has also been found to be highly-transmissible and, like the two other subvariants, can elude previous immunity, accounted for 27.8 per cent of COVID-19 variants in Canada as of May 22.
However, overall in Canada, the number of COVID-19 cases have been trending downward, which is leading health officials to feel “cautiously optimistic” for the summer months, Tam said Friday.
Indicators from daily case counts, lab tests and wastewater signals are stabilizing at the national level with most areas of the country continuing to see declines in COVID-19 activity.
“With the first day of summer just a few days away, steady improvements in epidemiological indicators are welcome and positive news, and I have supported the continued relaxation and pausing of measures,” Tam said.
But some areas of the country, including parts of Atlantic Canada and Saskatchewan, have seen some early warnings of increased COVID-19 activity in recent weeks, she added.
That’s why federal health officials are closely monitoring emerging variants in Canada and the rise in cases in the U.S. and Europe.
And it’s also why they aren’t ruling out the possibility of a possible surge in COVID-19 cases in this country over the summer.
“What you’ve seen in the States and in Europe, for example, and in Portugal, it is possible that there could be a resurgence here in Canada over the next weeks,” deputy chief health officer Dr. Howard Njoo said in French Friday during the briefing.
He stressed the importance of keeping up to date with COVID-19 vaccines, even though these new strains have demonstrated an ability to evade immunity. Even if the vaccines don’t prevent infection, they have been proven to reduce incidents of severe illness, hospitalization or death from the virus, Njoo said.
“So, it’s always important to stay up to date with your boosters, especially if there’s a resurgence of sorts of cases this summer.”
– with files from Reuters