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Data shows just how much more virulent are COVID-19 variants than the original strain

Delta variant by far the most deadly of all variant strains of the virus
covid-19
This scanning electron microscope image shows SARS-CoV-2 (yellow)—also known as 2019-nCoV, the virus that causes COVID-19—isolated from a patient in the U.S., emerging from the surface of cells (blue/pink) cultured in the lab.

The spread of COVID-19 variants of concern (VOCs) is likely to make the pandemic get a lot worse than was first expected, according to a couple of senior public health officials at the Dalla Lana School of Public Health at the University of Toronto.

This is based on an article published this week in the Canadian Medical Association Journal (CMAJ) by Dr. David N. Fisman and Associate Prof. Ahsleigh Tuite. Tuite has a PhD specializing in epidemiology and mathematical modeling from U of T.

Their research indicates the early variants and the notorious Delta variant are more virulent and more transmissible than the native strain of COVID-19, said their article. Fisman and Tuite used Ontario-based case data in their research, between February and June of 2021.

"They found higher risks of hospitalization, admission to intensive care and death with VOCs, particularly the Delta variant," said the article. 

The research included testing on more than 212,000 Ontario residents, said the article. When asked to comment on the data, Public Health Sudbury and Districts (PHSD) said it can only assume that some of those involved in the testing were local to this part of Northern Ontario. "The findings published in the Canadian Medical Association Journal are consistent with other sources of evidence that have found higher risks of hospitalization and death associated with COVID-19 variants of concern, including the Delta variant. It is our assumption that the 200,000 cases referenced in the study include cases from across the province, including the City of Greater Sudbury and the Sudbury and Manitoulin districts, but are unable to confirm this," read a statement from PHSD.

The research carried out by Fisman and Tuite showed the following, just based on the Alpha, Beta and Gamma variants:

  • 52 per cent more likely to result in hospitalization.
  • 89 per cent more likely to send a patient to the Intensive Care Unit (ICU).
  • 51 per cent more likely to cause death than the earlier version of COVID-19.

Research also showed that when the Delta variant was factored in, the statistics were more dire when compared to the early version of COVID-19.

  • 108 per cent more likely for hospitalization.
  • 235 per cent more likely for ICU.
  • 133 per cent more likely to die. 

That CMAJ article also prompted a supporting editorial this week from Kirsten Patrick, interim editor-in-chief at CMAJ.

She wrote that now is the time to push for more vaccinations among the public.

"Every eligible person in Canada for whom the vaccine is not contraindicated should receive it so that children younger than 12 years who are not yet vaccine-eligible, and people with risk factors for severe COVID-19, can be protected. Governments should step up efforts to deliver vaccinations to those eligible and prioritize the approval of safe vaccines for children," Patrick wrote.

"As Canada heads into its second winter of the COVID-19 pandemic, we must collectively learn from past mistakes and make sure to use all the tools at our disposal to avoid future lockdowns and prevent further devastation to our health care infrastructure."


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Len Gillis, local journalism initiative reporter

About the Author: Len Gillis, local journalism initiative reporter

Len Gillis is a Local Journalism Initiative reporter at Sudbury.com covering health care in northeastern Ontario and the COVID-19 pandemic.
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