The province says that while it has one of the lowest rates of active cases across the country, and that hospital and intensive care capacity remains stable, the effective reproduction number and percent positivity have “have increased slightly over the past week.”
The government says such an increase was “always expected” with people spending more time indoors due to the weather and with the easing of measures.
Announcing the latest update, Dr. Kieran Moore, Ontario’s chief medical officer of health, said at a press conference that it’s mainly young people who are driving up transmission.
“Sadly, it’s spreading mostly from the 20 to 39 year old age group,” he said. “It’s mostly in social settings where we take off our mask, where we have close contact as we move indoors in closed spaces, and that’s where most of the transmission is occurring.”
Moore said he doesn’t want the province to take a step back.
“It’s always been my advice to government that if we have to, we'll pause, but we won’t take step backwards,” he said, adding that he is committed to keeping schools open. He did however keep the option open for regional intervention in case infection rates go high too quickly.
A decline in vaccine effectiveness is another factor that could push the number of cases higher. Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, said in August that vaccines continue to work “exceptionally well” for preventing illness and death, but “what they can’t do anymore is prevent transmission.”
Ontario is recommending a third dose for vulnerable populations and health-care workers.
A study published in October in the New England Journal of Medicine says the effectiveness of the Pfizer vaccine against infection declines to 20 percent between five and seven months after the second dose.