In this thread I'll address the INACCURATE claim that the #COVID19 strain found in Québec is somehow more virulent & therefore the reason Québec was the epicentre of the pandemic in
I'll be referring to data from @McGillGenome study & @nextstrain
https://virological.org/t/genomic-epidemiology-of-early-introductions-of-sars-cov-2-into-the-canadian-province-of-quebec/553
1/11

1st I'd like to acknowledge @bjesseshapiro @cl_murall & other amazing #scientists whose work & analysis should be relied on by policy makers & media alike.

See my summary of their phylogenetic study of #SARSCoV2 in Québec https://twitter.com/DeNovo_Fatima/status/1308113245073534976
2/11

Analyzing samples from 734 Québec residents shows a global introduction of the virus into Québec. However, once the borders were closed & restriction were put in place, certain clades of the virus become more frequent.
What is a clade you ask? good question, keep reading
3/11

Think of clades as cousins. You & your cousin share the same ancestor (grand parents, great grand parents, etc.) & therefore your genes are very similar (this is why inbreeding is bad).
Viral clades are like cousin, they are closely related with a common ancestor
4/11

What are strains then? Another good question...
In the example of you & your cousins, if your family tree keeps growing w/ everyone reproducing w/ non-relatives, after many generations, you & your cousin, 100 times removed, are now markedly different.
same applies to viruses
5/11

In Québec once travel restrictions were put in place, depending on a number of factors, including people's movements & contacts within the province, a few of those clades had the opportunity to spread more & therefore become more prominent.
6/11

Now you're probably wondering what if those prominent clades were more virulent?
And that's a brilliant question to ask; good job, you're starting to think like a #scientist
Scientists have indeed looked at these scenarios & our current evidence shows that is not the case
7/11

The clades that became prominent in Québec were also present in other part of Canada & the U.S.

If these clades were more virulent as @ArrudaHoracio claims, then we would see
similar transmission dynamics in other regions
those clades out competing other clades
8/11

Lastly, so far clinical data has NOT shown association between severity of symptom or positivity rate and a particular clade.

Positivity rate = # of positive tests / total daily tests * 100

9/11

This shows that the devastation seen last spring was the result of
Early spring break
Delayed governmental response
Years of bad policies w/ respect to eldercare, childcare & healthcare in general
10/11

Disclaimer:
#Science in not a static set of facts. It evolves as we do more experiments, develop better methodologies & revise our thinking.
My assertions here are based on current evidence. Should our ongoing studies reveal a different outlook, I will update & revise.
11/11