Dr. Dawn Bowdish
@msmacrophage.bsky.social
Professor of Medicine, McMaster University
Executive Director of the Firestone Institute for Respiratory Health
Board of Directors Lung Health Foundation
#macrophages #aging #respiratoryinfections #vaccinations #immunity #inflammation #scicomm
Executive Director of the Firestone Institute for Respiratory Health
Board of Directors Lung Health Foundation
#macrophages #aging #respiratoryinfections #vaccinations #immunity #inflammation #scicomm
Happy Hallowe'en from the Bowdish lab.
October 31, 2025 at 12:17 PM
Happy Hallowe'en from the Bowdish lab.
What the latest on adult vaccines? Come join me and and exceptional panel at Zoomer media to get the lowdown.
• Recommended Vaccines & How To Get Them
‣ Navigating Provincial Health Systems
‣ The Role Your Pharmacist Can Play
‣ Emerging Science
‣ Fighting Disinformation & Vaccine Fatigue.
Free!
• Recommended Vaccines & How To Get Them
‣ Navigating Provincial Health Systems
‣ The Role Your Pharmacist Can Play
‣ Emerging Science
‣ Fighting Disinformation & Vaccine Fatigue.
Free!
October 3, 2025 at 1:02 PM
What the latest on adult vaccines? Come join me and and exceptional panel at Zoomer media to get the lowdown.
• Recommended Vaccines & How To Get Them
‣ Navigating Provincial Health Systems
‣ The Role Your Pharmacist Can Play
‣ Emerging Science
‣ Fighting Disinformation & Vaccine Fatigue.
Free!
• Recommended Vaccines & How To Get Them
‣ Navigating Provincial Health Systems
‣ The Role Your Pharmacist Can Play
‣ Emerging Science
‣ Fighting Disinformation & Vaccine Fatigue.
Free!
Vaccine programs are decided by more than efficacy and efficacy - here's a summary of what the National Advisory Council on Immunization (Canada) includes. Our review doesn't address the programmatic, cost, and social considerations, which are also important. 11/n
September 25, 2025 at 4:04 PM
Vaccine programs are decided by more than efficacy and efficacy - here's a summary of what the National Advisory Council on Immunization (Canada) includes. Our review doesn't address the programmatic, cost, and social considerations, which are also important. 11/n
We also make a case to increase to increase the range of vulnerable populations. Canada has been a leader in including congregate living and equity-deserving groups in priority populations (#elbowsup !) but people living with lung and heart issues should be included 10/n.
September 25, 2025 at 4:04 PM
We also make a case to increase to increase the range of vulnerable populations. Canada has been a leader in including congregate living and equity-deserving groups in priority populations (#elbowsup !) but people living with lung and heart issues should be included 10/n.
There has been some frustration that COVID-19 vaccines don't last longer but neither does protection from either infection or vaccination for other viruses. When we compare protection < 3 months and > 3 months, COVID-19 vaccines look pretty good, esp considering rapid variant change 9/n
September 25, 2025 at 4:03 PM
There has been some frustration that COVID-19 vaccines don't last longer but neither does protection from either infection or vaccination for other viruses. When we compare protection < 3 months and > 3 months, COVID-19 vaccines look pretty good, esp considering rapid variant change 9/n
...but despite that disadvantage, levels of protection from symptomatic infection and severe disease are similar between COVID & influenza vaccines. Note that protection against symptomatic infection is VERY hard to estimate because people who don't get sick don't get tested. 8/n
September 25, 2025 at 3:58 PM
...but despite that disadvantage, levels of protection from symptomatic infection and severe disease are similar between COVID & influenza vaccines. Note that protection against symptomatic infection is VERY hard to estimate because people who don't get sick don't get tested. 8/n
Now look at how complicated it is to compare COVID-19 vaccine effectiveness. In influenza studies it is often possible to assess which strain a person was infected with so you can assess vaccine effectiveness by strain. COVID-19 vaccines are almost never matched with the circulating variants.. 7/n
September 25, 2025 at 3:57 PM
Now look at how complicated it is to compare COVID-19 vaccine effectiveness. In influenza studies it is often possible to assess which strain a person was infected with so you can assess vaccine effectiveness by strain. COVID-19 vaccines are almost never matched with the circulating variants.. 7/n
Before we get to the data - I just want to give a huge shoutout to @belongia.bsky.social l for leading so many high quality studies on influenza effectiveness - look how easy to compare year-to-year. 6/n
September 25, 2025 at 3:55 PM
Before we get to the data - I just want to give a huge shoutout to @belongia.bsky.social l for leading so many high quality studies on influenza effectiveness - look how easy to compare year-to-year. 6/n
Comparable data is hard to find, but when we looked at 2022/23 & 2023/24 data we see that deaths are still higher for COVID than influenza *BUT* looking at % hides the fact that COVID-19 is more contagious and in 23/24 there were almost 3x as many COVID hospitalizations than influenza. 4/n
September 25, 2025 at 3:54 PM
Comparable data is hard to find, but when we looked at 2022/23 & 2023/24 data we see that deaths are still higher for COVID than influenza *BUT* looking at % hides the fact that COVID-19 is more contagious and in 23/24 there were almost 3x as many COVID hospitalizations than influenza. 4/n
I was so touched to get this portrait from #torontofringe volunteer @moccouh.bsky.social who was inspired by my show ‘The Perils of Being Born in the Fall’. The audience has been so positive about the show and quite a few have said ‘there should be more science shows!’ -#scicomm folks, take note!
July 8, 2025 at 12:26 PM
I was so touched to get this portrait from #torontofringe volunteer @moccouh.bsky.social who was inspired by my show ‘The Perils of Being Born in the Fall’. The audience has been so positive about the show and quite a few have said ‘there should be more science shows!’ -#scicomm folks, take note!
Second show at the #TorontoFringe starting at 8:15 - met people outside who are coming based on recommendations from friends. I’ve got word-of-mouth! Tickets available all through the week. fringetoronto.com/fringe/show/... #scicomm
July 4, 2025 at 11:58 PM
Second show at the #TorontoFringe starting at 8:15 - met people outside who are coming based on recommendations from friends. I’ve got word-of-mouth! Tickets available all through the week. fringetoronto.com/fringe/show/... #scicomm
Fringe Festival volunteers are the best! Thank you to @moccouh.bsky.social and my tech Daniel and all the other Fringe staff for making the first showing of The Perils of Being Born in the Fall great! #torontofringe
July 2, 2025 at 10:32 PM
Fringe Festival volunteers are the best! Thank you to @moccouh.bsky.social and my tech Daniel and all the other Fringe staff for making the first showing of The Perils of Being Born in the Fall great! #torontofringe
Come see ‘The Perils of Being Born in the Fall’ premiering Wed July 2nd at the Toronto Fringe Festival 5pm - Helen Gardiner Phelan Playhouse. Pay what you can! 7 shows in total. #torontofringe Tickets and info fringetoronto.com/fringe/show/...
July 2, 2025 at 12:32 AM
Come see ‘The Perils of Being Born in the Fall’ premiering Wed July 2nd at the Toronto Fringe Festival 5pm - Helen Gardiner Phelan Playhouse. Pay what you can! 7 shows in total. #torontofringe Tickets and info fringetoronto.com/fringe/show/...
Just finished up tech rehersal at the Helen Gardiner Phelan Playhouse - it’s a lovely, intimate venue. Come see ‘The Perils of Being Born in the Fall’ at the #torontofringe Tickets are ‘pay what you can - see you there, Toronto! fringetoronto.com/fringe/show/...
June 30, 2025 at 12:18 AM
Just finished up tech rehersal at the Helen Gardiner Phelan Playhouse - it’s a lovely, intimate venue. Come see ‘The Perils of Being Born in the Fall’ at the #torontofringe Tickets are ‘pay what you can - see you there, Toronto! fringetoronto.com/fringe/show/...
Repeat vaccination does not affect the T cells ability to make cytokines, even in vulnerable populations. They may express some activation markers but they are definitely not turned off. 10/n
June 6, 2025 at 7:12 PM
Repeat vaccination does not affect the T cells ability to make cytokines, even in vulnerable populations. They may express some activation markers but they are definitely not turned off. 10/n
How do you know when a T cell is truly 'exhausted'? It expressed these markers ***AND*** it loses its function. Here's where our study shines - we looked at the T cells' ability to produce at least 1 cytokine ('functionality') or more than 1 cytokine ('polyfunctionality'). 9/n
June 6, 2025 at 7:10 PM
How do you know when a T cell is truly 'exhausted'? It expressed these markers ***AND*** it loses its function. Here's where our study shines - we looked at the T cells' ability to produce at least 1 cytokine ('functionality') or more than 1 cytokine ('polyfunctionality'). 9/n
...than an exhaustion marker. When the antigen decreases ( infection or vaccine clears), the off-switches signal that it's time to close up the inflammatory shop. It is rare that antigens don't go away but in cancer that chronic stimulation can lead to sustained expression of the PD1 off-switch. 8/n
June 6, 2025 at 7:09 PM
...than an exhaustion marker. When the antigen decreases ( infection or vaccine clears), the off-switches signal that it's time to close up the inflammatory shop. It is rare that antigens don't go away but in cancer that chronic stimulation can lead to sustained expression of the PD1 off-switch. 8/n
When there is a lot of antigen around (during infection or vaccination) the balance between the on-switch (antigen-stimulation) and the off-switch (PD-1 & friends) favours being on - the T cells expand & differentiate & work their magic. Here PD1 is better described as an 'activation marker'....7/n
June 6, 2025 at 7:08 PM
When there is a lot of antigen around (during infection or vaccination) the balance between the on-switch (antigen-stimulation) and the off-switch (PD-1 & friends) favours being on - the T cells expand & differentiate & work their magic. Here PD1 is better described as an 'activation marker'....7/n
(Aside) for reference you can't overwhelm an immune system and as evidence I present to you Ontario's child vaccine schedule - you can have lots of vaccines in short order and nothing bad happens. 5.5/n
June 6, 2025 at 7:06 PM
(Aside) for reference you can't overwhelm an immune system and as evidence I present to you Ontario's child vaccine schedule - you can have lots of vaccines in short order and nothing bad happens. 5.5/n
And for fans of the #onpoli podcast or ‘The Pod’. I am from @mcmasteru.bsky.social which is in Hamilton and I was in the Bill Davis studio (told you I was a fan @spaikin.bsky.social ) #ifyouknowyouknow
May 12, 2025 at 4:56 PM
And for fans of the #onpoli podcast or ‘The Pod’. I am from @mcmasteru.bsky.social which is in Hamilton and I was in the Bill Davis studio (told you I was a fan @spaikin.bsky.social ) #ifyouknowyouknow
I appreciate public broadcasters so much for putting out good information in such an accessible manner. Find @tvotoday.bsky.social on YouTube or TV. I got choked up listening to @jillpromoli.bsky.social talk about losing a child to infection. I admire her #ForJudeForEveryone campaign immensely.
May 12, 2025 at 4:50 PM
I appreciate public broadcasters so much for putting out good information in such an accessible manner. Find @tvotoday.bsky.social on YouTube or TV. I got choked up listening to @jillpromoli.bsky.social talk about losing a child to infection. I admire her #ForJudeForEveryone campaign immensely.
Talking measles vaccination on @tvotoday.bsky.social with @picardonhealth.bsky.social @jillpromoli.bsky.social and my @machealthsci.bsky.social colleague Jeff Pernica. Thank you @namshine.bsky.social and the TVO team for addressing this important issue. 8pm tonight. #vaccineswork
May 12, 2025 at 4:45 PM
Talking measles vaccination on @tvotoday.bsky.social with @picardonhealth.bsky.social @jillpromoli.bsky.social and my @machealthsci.bsky.social colleague Jeff Pernica. Thank you @namshine.bsky.social and the TVO team for addressing this important issue. 8pm tonight. #vaccineswork
No fancy plate washer for us - next he had to bang out all those plates on his bench.
May 1, 2025 at 9:30 PM
No fancy plate washer for us - next he had to bang out all those plates on his bench.
Ha! Here's a picture of Braeden's great stack of plates - he did this for daaaysss.
May 1, 2025 at 9:27 PM
Ha! Here's a picture of Braeden's great stack of plates - he did this for daaaysss.
Huge shout out to Braeden Cowbrough for doing all those titres and to Dr Jessica Breznik (former @miramcmaster.bsky.social currently @mcmasternexus.bsky.social PDF) for analytic skills. Thanks to the rest of the COVID-in-LTC team & our wonderful participants! Fin @ofidjournal.bsky.social
May 1, 2025 at 5:06 PM
Huge shout out to Braeden Cowbrough for doing all those titres and to Dr Jessica Breznik (former @miramcmaster.bsky.social currently @mcmasternexus.bsky.social PDF) for analytic skills. Thanks to the rest of the COVID-in-LTC team & our wonderful participants! Fin @ofidjournal.bsky.social