LIVE AT 2:30 MT 2-hour wildfire evacuation notice issued for some Fort McMurray neighbourhoods
A wildfire evacuation alert for some Fort McMurray residents has been updated to a two-hour evacuation notice.
A newly released survey finds nearly all Canadian adults had antibodies against COVID-19 for about half of 2022, with most acquiring them through a previous infection.
The results, released Tuesday by Statistics Canada in partnership with the Public Health Agency of Canada and COVID-19 Immunity Task Force, show that 98.1 per cent of Canadian adults living in the country's 10 provinces had antibodies against SARS-CoV-2, the virus that causes COVID-19, between April and August 2022.
These individuals acquired antibodies through either vaccination, previous infection or both.
Over that five-month period, 53.9 per cent developed antibodies through a past infection.
This is in comparison to the results of a previous version of the survey done between November 2020 and April 2021 that found 2.6 per cent of Canadians had COVID-19 antibodies due to a previous infection.
A report detailing the findings says while almost 54 per cent of Canadians surveyed had antibodies from an infection, the actual proportion of those infected since the start of the pandemic is likely higher.
"This is due, in part, to the fact that an antibody response to an infection may not always be detectable, especially among those who are vaccinated who may generate fewer antibodies following a subsequent infection. In addition, antibody levels can decrease over time," the report says.
The survey used a technique known as dried blood spot testing to detect COVID-19 antibodies from vaccination or a past infection, as well as saliva samples to determine a current or recent infection.
A total of 105,998 people were chosen to participate in the survey, of which 30.7 per cent completed a questionnaire asking about general health and exposure to COVID-19. Of those who completed the questionnaire, nearly 54 per cent provided a blood sample and 54.5 per cent provided a saliva sample.
The body produces antibodies to defend against diseases and in response to vaccination.
However, they do decrease over time and the report says some people previously infected with COVID-19 or who have been vaccinated may no longer have detectable levels of antibodies.
But while antibodies may decrease with time, the report says it does not mean a person's immunity has waned.
Rather, an individual may have developed cell-mediated immunity, which activates specialized white-blood cells called T cells.
The report says dried blood spot testing also does not measure cell-mediated immunity.
Even without detectable antibodies, the report adds that cell-mediated immunity could be enough to protect someone against severe COVID-19 symptoms. The mere presence of antibodies alone also isn't enough to suggest a person could fend off a new infection or any serious symptoms.
The survey found as many as two out of five Canadians with antibodies from a previous infection were unaware they had been infected, either because they never tested positive or did not suspect an infection.
Among those who previously tested positive for COVID-19, antibody levels were higher between 14 and 90 days post-infection before gradually decreasing over time.
"While this is indicative of decreasing antibodies, there are other factors which could impact this analysis," the report says.
"For example, since vaccines may lead to a lesser antibody response following an infection, the percentage of Canadians with antibodies from infection may be affected by changing vaccination rates over time. Further, since the survey focuses on first infections, re-infections would also impact this analysis as these could lead to a rebound in antibody levels."
Canadians with a disability or underlying health conditions were less likely to have antibodies from a previous infection compared to those who did not report a disability or health condition.
Those 18-34 and 35-49 were also more likely to have antibodies from a previous infection than older Canadians were.
Antibody levels from infection varied between population groups, ranging from as low as 53 per cent for Chinese Canadians to as high as 80.7 per cent for Black Canadians.
Across provinces, Nova Scotia had the lowest proportion of residents who developed antibodies from infection at 46.5 per cent, while Quebec (56.5 per cent), Alberta (57.4 per cent) and Saskatchewan (57.4 per cent) had the highest rates.
The survey did not include data from the three territories, those under 18 or people living on reserve, in institutions or Canadian Forces Bases.
A wildfire evacuation alert for some Fort McMurray residents has been updated to a two-hour evacuation notice.
Canadian LifeLabs customers who filed an application for a class-action settlement began receiving their payments this week, though at a much lower amount than initially expected.
Nobel laureate Alice Munro, the Canadian literary giant who became one of the world's most esteemed contemporary authors and one of history's most honoured short story writers, has died at age 92.
Wildfires have led Environment Canada to issue air quality advisories for parts of B.C., Alberta, Manitoba, Saskatchewan and the Northwest Territories, as forecasters warn the smoke could drift farther east.
Saskatchewan RCMP have revealed that a historic sexual assault investigation has led to the discovery of crimes against children dating back to 2005.
An American accused of sexually assaulting a Pennsylvania college student in 2013 and later sending her a Facebook message that said, 'So I raped you,' has been detained in France after a three-year search.
The annual list of Canada's top restaurants in the country was just released and here are the places that made the 2024 cut.
Ontario Provincial Police are responding to a fatal collision involving two vehicles on Highway 417 in Ottawa's west end on Tuesday morning.
The Israeli flag is flying at Ottawa City Hall today to mark the country's national day, with plans to hold a private ceremony to mark Israel's Independence Day. There is a significant police presence at City Hall, including security barriers outside the main doors.
A team is ready to help an entangled North Atlantic right whale in the Gulf of St. Lawrence.
A $200 reward is being offered by a North Vancouver family for the safe return of their beloved chicken, Snowflake.
Two daughters and a mother were reunited online 40 years later thanks to a DNA kit and a Zoom connection despite living on three separate continents and speaking different languages.
Mother's Day can be a difficult occasion for those who have lost or are estranged from their mom.
YES Theatre Young Company opened its acclaimed kids’ show, One Small Step, at Sudbury Theatre Centre on Saturday.
An Ottawa pizzeria is being recognized as one of the top 20 deep-dish pizzas in the world.
A family of fifth generation farmers from Ituna, Sask. are trying to find answers after discovering several strange objects lying on their land.
A Listowel, Ont. man, drafted by the Hamilton Tigercats last week, is also getting looks from the NFL, despite only playing 27 games of football in his life.
The threat of zebra mussels has prompted the federal government to temporarily ban watercraft from a Manitoba lake popular with tourists.