Thread by @awong37

Hi everyone. I thought I would try to explain what all these 'variants' of COVID-19 are, and are they really that bad? I feel this has relevance to #SK & Canada because we are seeing growth of all three key VoCs at once. Start w/ graphic below. (1/n) #COVID19SK

All viruses mutate (change) over time. Most of these mutations are meaningless, but sometimes the virus changes in ways that allow it infect cells or reproduce itself more effectively. This confers a "fitness advantage", and over time more "fit" viruses become dominant. (2/n)

When certain mutations confer advantages such that the virus can grow and spread within populations & infect people more quickly and/or make people sicker, these are termed "variants of concern". Several are well-described now. We'll focus on the 3 relevant in Canada. (3/n)

The key mutations of interest for all three of these variants of concern are located in the spike protein, which allows the virus to bind to cells and also serves as the primary target for COVID-19 vaccines. (4/n)

The B.1.1.7 variant originated in the United Kingdom and is the dominant variant in #SK (>99%) and Canada. It is more transmissible and associated with more severe illness and death. It contains a mutation in the spike protein, N501Y, that our lab uses to detect it. (5/n)

The B.1.351 variant originated in South Africa and is distinct from B.1.1.7 but shares mutations including N501Y and another key mutation called E484K. E484K seems to confer the ability for the virus to "impact" immunity from prior infection or vaccination. (6/n)

The P.1 variant originated in Brazil & also contains N501Y & E484K. The P.1 variant is dominant variant in Brazil, which is being devastated with huge numbers of cases and deaths now. Many reports of reinfection w/ P.1 after natural infection with wild-type virus. Scary. (7/n)

In order of badness, we are likely thinking B.1.1.7 least bad, then P.1 & B.1.351 much worse. Vaccine activity against all these variants is somewhat lessened but reasonable to believe vaccines will still markedly reduce severe illness and death. (8/n)

The emergence of all of these variants across #SK & Canada is super-charging the number of cases as well as the number of persons who become severely ill. It is the worst timing for the country as we are still struggling to get vaccine doses out as fast as possible. (9/n)

Good news? All the measures we took before to prevent infection with the "old" SARS-CoV-2 work just as well to prevent infection with these new variants. We just need to be far more diligent in the steps that we are taking, i.e. double-masking, hand-washing, etc. (10/n)

Trying to reduce or prevent additional spread of P.1 & B.1.351 by eliminating non-essential travel b/w provinces would seem to make sense right now, as would some kind of quarantine following inter-provincial travel as well. (11/n)

P.1 is circulating most widely in BC and ON with new cases in AB, B.1.351 is circulating most widely in QC. B.1.1.7 pretty much everywhere else and remains dominant VoC in #SK currently (943/951=99% of all VoC cases). (12/n)

None of this is good for #SK or Canada. Despite vaccinating our most vulnerable (i.e. LTC, >80 years), this 3rd wave will be the worse we will experience with widespread community transmission throughout the country. It's already happening now. (13/n)

To buy time for vaccine to catch up w/ VoCs in #SK, we need everyone to do their part:

- stay home
- keep bubbles very tight
- test / isolate if symptoms
- no non-essential travel
- be nice to contact tracers
- be kind

Please, take care of each other, #SK. #COVID19SK