Covid-19: Canada considers B.1.617 as a ‘variant of concern’

India — Days after the World Health Organization (WHO) designated it a variant of concern or VOC, Canadian health authorities are now considering the B.1.617 mutation of Covid-19 in the same category.

The variant, which was first detected in India, was added to the Public Health Agency of Canada’s VOC list on Thursday.

In its Outbreak Update, the agency said that it was “following the variants of concern first identified in the United Kingdom (B.1.1.7), South Africa (B.1.351), Brazil (P.1) and India (B.1.617)”. It added, “Monitoring for genetic changes in the virus allows us to better understand the potential impact of the mutations.”

In a statement issued on Thursday, Canada’s chief public health officer Dr Theresa Tam noted the WHO earlier this week based on “increased negative impacts compared to other circulating virus variants”.

She said, “Early findings of the WHO SARS-CoV-2 Virus Evolution Working Group indicate that this variant appears to have higher rates of transmission; as well, preliminary evidence suggests the variant may be associated with reduced effectiveness to some Covid-19 treatments.”

Tam also noted that VOCs “can be associated with more severe illness and increased risk of death”.

She pointed that out that such variants now represent “a majority” of Covid-19 cases in Canada, and the UK variant is present in all provinces and territories and accounts for more than 95% of VOCs sequenced to date.

However, she added that “regardless of which variants are circulating, vaccination, in combination with public health and individual measures work to reduce spread”.

She said that Canada has so far recorded 28 cases of adverse reactions related to the AstraZeneca vaccine, involving blood clots (thrombosis) with low levels of blood platelets.

As some Canadian provinces, led by Ontario, have paused administration of the vaccine for first doses, Tam said that while generally, vaccine series are completed with the same vaccine, in some cases, they can be completed with a different one.

She said that it “may be possible that using a different vaccine type could result in a greater immune response, providing broader protection against Covid-19.”