While the risk of hospitalisation from the Omicron variant of Covid-19 is lower than that for Delta, the fact that it’s extremely transmissible is driving up admissions because of the sheer volume of cases, Canada’s chief public health officer has said.

In a series of tweets on Sunday as hospitalisations spiked across several provinces, Dr Theresa Tam said one of the key concerns was that while surveillance and recent studies indicates the risk of hospitalisation from Omicron was lower compared to Delta, “sudden acceleration” caused by the variant “with an enormous volume of cases is driving up severe illness trends”.

The current daily case counts, she pointed out, were 400% higher than the peak for the third wave of the pandemic in Canada, when on average 8,730 cases were reported daily in mid-April last year. Given this scenario, she added that it was “not unexpected we’ll see further increases in hospitalisation trends”.

Her remarks came as provinces like Quebec and Ontario reported high hospitalisation numbers. Quebec set a new record with 2,436 on Sunday, while Ontario had 2,419.

The rapid spread of Omicron has also led to the Canadian Armed Forces (CAF) being called in to assist health authorities. Members of the military were rendering help in the remote First Nations territory of Bearskin Lake in northern Ontario, where half the population has been infected.

Defence minister Anita Anand has also said that 200 CAF personnel have been deployed at vaccination centres in Quebec, as it ramps up its drive to deliver boosters.