Jeff Gilchrist

To learn how to see what variants are circulating in your area, please read this guide ( bsky.app/profile/jeff... ). 15/

To learn how to create a Sankey diagram of variants circulating in your area, please read this guide ( bsky.app/profile/jeff... ). 14/

The visualization tool for variants was created by @mikehoney.bsky.social and the source of this data can be found at ( app.powerbi.com/view?r=eyJrI... ). 13/

You can find weekly Ontario stats including variants at ( covid.gilchrist.ca/Ontario.html ). 12/

Sankey diagram showing the evolution of sequenced viral genomes in Ontario, Canada, from December to February 2026.

The SanKey diagram shows you variant lineages and you can follow back where that variant came from. 11/

How do variant designations work and relate to our immunity? How do variant designations work and relate to our immunity? Variants: JN.1 vs KP.2 vs KP.3.1.1 Written by: Jeff Gilchrist & Paul Seaman Link to this document: https://tinyurl.com/VariantsSummer2024 L...

As time goes, keeping track of the virus evolution is getting more complex. You can learn more about how variant naming works and mutations from this document ( docs.google.com/document/d/1... ). 10/

The XFY variant family is a recombinant of XFG.5.1 Stratus and NB.1.7.1 Nimbus, so both of the most common variant families together. 9/

RE.1.2 and RE.2.2.4 are part of the BA.3.2.* Cicada family, also known as BA.3.2.2.1.2 and BA.3.2.2.2.2.4. PQ.2.1.3 and PQ.2.8.1 are part of the Nimbus family, also known as NB.1.8.1.2.1.3 and NB.1.8.1.2.8.1. 8/

Two BA.3.2.* Cicada family variants are now on the board with RE.1.2 at 1.5% and RE.2.2.4 at 1.3%. 7/

Line graph showing specific COVID-19 variant frequencies in Ontario, Canada, from December to February 2026.

Looking at specific variants, PQ.2.8.1 continues to increase and in first place at 12.1% while PQ.2.1.3 is just behind at 10.2%. The next closest variant is significantly lower with XFG.1.1.2 at 6.4%, then PQ.2.1 at 6.1% and QK.2 at 4.9%. 6/

Line graph showing COVID-19 BA.3.2.* Cicada variant family frequency in Ontario, Canada, from December to February 2026.

The BA.3.2 "Cicada" family has been increasing in Ontario with its descendant RE.* and a total of 27 sequences that have been regularly sequenced since late January now at 3%. 5/

Line graph showing COVID-19 variant family frequencies in Ontario, Canada, from October to February 2026.

The XFG.* "Stratus" family temporarily jumped back up to 62% but has now dropped down to 49% while the variant family NB.1.8.1.* "Nimbus" dipped and has returned back up to 42% of sequenced genomes from COVID tests. The XFY.* family has been slowly increasing and takes third place at 3.4%. 4/

The youngest age group 0-4 currently have a hospitalization rate due to COVID that is 4x higher than age 5-17, 2.6x higher than age 18-49, and similar levels to adults 50-64. 3/

Graph of New hospitalization rate in Ontario due to COVID by age group.

Looking at age groups, those age 75+ had the highest rates of hospitalization due to COVID and continues to increase. Second place is age 65-74 and their levels are currently decreasing while age 0-4 has the third highest rate and decreased significantly since last update. 2/

Graph of New hospitalizations in Ontario due to COVID, Influenza or RSV.

Graph of New hospitalizations in Ontario due to COVID, Influenza or RSV (100% Stacked).

*** Ontario Virus & Variant Update | Mar 1 ***

Hospitalizations due to COVID remained stable at 215 in the last update. Influenza hospitalizations dropped very slightly to 51 and RSV decreased to 200. 🧵1/

#Ontario #Virus #Variant #COVID #RSV #Influenza #Hospital

Is UoT's Prof. Siegel on BSky?

The risk of the airborne transmission of disease correlates with the amount of infectious exhaled aerosol. Since people exhale CO2 with aerosol, its conc has been used as proxy for exhaled aerosol

In this article, researchers propose a new way to estimate risk of transmission

Those of us with ERVs or HRVs I guess are continuously "burping" the house non-stop so even better?

Yes, fall 2024 was the first year I believe so this would be the second RSV "season" but there was a lot of confusion last year when it was first released so not as much uptake the first year and may have been better this year.

To learn how to see what variants are circulating in your area, please read this guide ( bsky.app/profile/jeff... ). 12/

To learn how to create a Sankey diagram of variants circulating in your area, please read this guide ( bsky.app/profile/jeff... ). 11/

The visualization tool for variants was created by ( @mikehoney.bsky.social ) and the source of this data can be found at ( app.powerbi.com/view?r=eyJrI... ). 10/

You can find weekly Ontario stats including variants at ( covid.gilchrist.ca/Ontario.html ). 9/

Sankey diagram showing the evolution of sequenced viral genomes in Ontario, Canada, from November to December 2025.

The SanKey diagram shows you variant lineages and you can follow back where that variant came from. 8/

How do variant designations work and relate to our immunity? How do variant designations work and relate to our immunity? Variants: JN.1 vs KP.2 vs KP.3.1.1 Written by: Jeff Gilchrist & Paul Seaman Link to this document: https://tinyurl.com/VariantsSummer2024 L...

PQ.2.1.3 is also part of the Nimbus family, also known as NB.1.8.1.2.1.3. You can learn more about variant naming and mutations from this document ( docs.google.com/document/d/1... ). 7/

Line graph showing specific COVID-19 variant frequencies in Ontario, Canada, from November to December 2025.

Looking at specific variants, PQ.2.1.3 is in first place at 13.6% and continues to grow. XFG.3.13 is in second place at 3.9% and XFG.5.1 is in 3rd place at 3.1% followed by XFG.2 at 2.5%. 6/

Line graph showing COVID-19 variant family frequencies in Ontario, Canada, from September to December 2025.

The XFG.* "Stratus" family currently sits in first place at 66% while the next closest variant family NB.1.8.1.* "Nimbus" has 26.3% of sequenced genomes from COVID tests. The BA.3.2 "Cicada" family has now made an appearance in Ontario with its descendant RE.2.2.4. 5/

Graph of New hospitalization rate in Ontario due to COVID, Influenza or RSV by age group.

Looking at age groups, those 75+ had the highest rates of hospitalization due to COVID followed by age 65-74 and then age 0-4 for third highest rate. There were multiple weeks since September 2025 where the youngest age group 0-4 had the second highest rate of hospitalizations due to COVID. 4/

Influenza has been doing the opposite, increasing significantly each year from 3,486, to 4,380 in 2024, to 12,818 in 2025. 3/

Graph of New hospitalizations in Ontario due to COVID, Influenza or RSV, grouped by calendar year.

Looking back over the past few years, new hospitalizations for RSV have remained pretty stable the last two years around 2,500 and a decrease from 2023, while COVID has been significantly dropping each year, 26,571 in 2023 to 15,739 in 2024 to 6,788 in 2025. 2/