Most Canadians have hybrid COVID-19 immunity. Could it prevent a fall wave?
Global News
By March 2023, more than 75 per cent of the population had immunity because of a COVID-19 infection, according to a new CMAJ study.
After more than three years of COVID-19, most people in Canada have developed immunity against the virus through a mix of infection and vaccination, data shows.
By March 2023, more than 75 per cent of the population had immunity because of a COVID-19 infection, according to a study published in the Canadian Medical Association Journal (CMAJ) Monday.
Researchers at the COVID-19 Immunity Task Force looked at blood samples of thousands of Canadians of all ages collected between March 2020 and March 2023 and found that the Omicron variant led to a rapid rise in infection-induced antibodies last year.
During the Omicron waves, the rates of infection-acquired immunity appeared to be highest among younger Canadians, the CMAJ research showed.
“Data up to March 2023 indicate that most people in Canada had acquired antibodies against SARS-CoV-2 through natural infection and vaccination,” the authors said in the peer-reviewed study.
The research sheds new light on the impact of the highly transmissible Omicron variant — which was first detected in Canada in December 2021 — which caused many Canadians to get infected for the first time with COVID-19.
The study also said most people in the country had been vaccinated by the time the Omicron variant surged in Canada – and that coupled with an uptick in cases ushered in “an era of hybrid immunity” that potentially could protect against infection for months.
Despite the high vaccine coverage, the hybrid immunity from vaccines and previous infections was not enough to slow the spread of Omicron, the CMAJ study stated.
