More than 1% of Toronto people have COVID-19 antibody: Canadian Blood Services study

A new study suggests that more than 1% of Toronto citizens have the COVID-19 antibody in their blood, which is slightly higher than the entire Canadian population at the end of spring.

Canadian Blood Services and Canadian COVID-19 Immunity Task Force (CITF) announced the final results of a joint 9-state SARS-CoV-2 serum prevalence study conducted Tuesday. area.

Overall, based on the results, less than 1% of Canadians had antibodies to the virus.

Samples were collected between May 9 and June 18, revealing that only 0.7% of Canadian adult blood donors were positive for antibodies to COVID-19.

“…These results once again show that by the end of May, a small number of Canadians were infected with SARS-CoV-2,” CITF Co-Chair Professor Katherine Hankins said in a press release. Stated. “This shows that the risk of infection is significantly reduced if all actors, especially individual citizens, follow good public health practices,” she added.

Antibodies are reportedly an important indicator of past infections by the virus and are usually detected within 2 weeks.

Of the 37,737 samples collected, more than half were from male donors, with the majority of donors aged 40-59.

Over 19,800 samples were taken from Ontario, followed by 5,644 samples from Alberta and 4,962 samples from British Columbia.

Results showed low seroprevalence of SARS-CoV-2 in all states and cities across Canada, according to the regions included in the study.

The report found that Ontario had a slightly higher seroprevalence than other states, and women had a slightly higher seroprevalence than men, but ultimately there was no difference between age groups. It has been.

“Prince Edward Island and New Brunswick had the lowest seroprevalence of 0% and 0.26%, respectively, while Ontario had the highest of 0.96%,” said Deputy Head of Epidemiology and Surveillance for Canadian Blood Services. Sheila O’Brien said in the announcement.

Quebec was not included in the study, but the report reports the highest seroprevalence in the country to date (2.23%), based on a recent study by Hema Quebec.

Of the major Canadian cities, Ottawa had the highest seroprevalence of 1.29%, followed by Toronto with 1.07% and Vancouver with 0.60%.

Research suggests that by the end of May, a very small number of Canadians had been infected with the virus, but Hankins may find that the result is actually an underestimation of the number of Canadians who carry the COVID-19 antibody. I pointed out that there is a property.

“First, antibody levels decline rapidly and in some people may have disappeared by the time of the test,” Hankins said. “Second, blood donors are generally health-conscious and healthier than the average person.”

The researchers also noted that the results of this study pointed to the need for more testing, due to the increasing number of cases of COVID-19 in some parts of the country.

“…Even if you double or triple the estimate in this study, it’s unlikely that your population’s immune levels will be high enough to delay the second wave of COVID-19 infections,” CITF co-founded. Chair Professor David Nayler said in the release. “Therefore, it is important to strengthen testing and tracking nationwide to reduce risks in environments such as workplaces and schools and to quickly interrupt the transmission chain and prevent spread of infection.”

The CITF was launched by the federal government in late April 2020 and is tracking the spread of the virus throughout the country.

Canadian Blood Services is a nonprofit charity managed by Health Canada that provides blood, plasma, and stem cell services to patients on behalf of all provincial and territorial governments except Quebec.