Evidence of meeting #23 for Health in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was know.
A recording is available from Parliament.
6:25 p.m.
Liberal
The Chair Liberal Sean Casey
Thank you, Mr. Garon.
Thank you, Dr. Yu.
Mr. Davies, please, for two and a half minutes.
6:25 p.m.
NDP
Don Davies NDP Vancouver Kingsway, BC
Thank you, Mr. Chair.
I'd like to go back, if I can, to the issue of infection-acquired immunity. I have seen other data and heard from other immunologists who have stated that using a vaccine that was developed against the alpha variant and boosting it to deal with a virus in circulation that has mutated significantly, particularly on the spike protein, by logic should reduce its efficacy. What would your position be on that, Dr. MacDonald? In other words, if we get a third booster or a fourth booster, are we not just boosting the production of antibodies to deal with a virus that is not particularly in circulation as it once was?
6:25 p.m.
Professor of Pediatrics (Infectious Diseases), Dalhousie University and IWK Health Centre, As an Individual
Yes, but let me explain.
The companies have been looking very hard about putting together a vaccine that would have two pieces in it: one that would have the spike protein that was in the original Wuhan virus, which is in the the vaccine that we've been using on millions and millions of people; and the other one with the omicron variant of that spike protein. They are looking at what would happen if these were given together.
I think that's really the question you're asking, and yes, that would probably—
6:25 p.m.
NDP
Don Davies NDP Vancouver Kingsway, BC
If I may interrupt, it actually isn't. You've nailed the nub of the question. That would make sense to me if we were...but we're actually using the vaccine that is purely developed for the alpha spike protein.
I'm just wondering how effective that can be against a spike protein that has gone through such significant mutations.
6:25 p.m.
Professor of Pediatrics (Infectious Diseases), Dalhousie University and IWK Health Centre, As an Individual
It has gone through significant mutations, but there are a lot of places that it hasn't changed. When you respond, it's to all of the different pieces that are on the spike protein. That's why it still works against serious disease, against omicron, if you have been immunized. You're not going to die at the same rate, and you're not going to have hospitalization at the same rate.
6:30 p.m.
NDP
Don Davies NDP Vancouver Kingsway, BC
Right, yes. The data seem to back that up.
There is another question that I want to challenge you on a little bit.
The evidence I've received is that if you are infected by omicron, certain immunologists tell me that it does provide protection against previous versions of the virus, that it would actually contain some of the same...I don't know the proper term.
6:30 p.m.
Professor of Pediatrics (Infectious Diseases), Dalhousie University and IWK Health Centre, As an Individual
It has some of it, but it is not good against delta, for example. It's wimpy against delta, okay?
There are two phylogenetic trees that have come off: the omicron branch, blah, blah, blah, and the one that had alpha, beta and delta off of it. They are quite far apart in terms of what they're like. Omicron is not as “good” an antigen, antibody generator as the ones that were off Wuhan and the beginning one. They do better at stimulating neutralizing antibodies against the spike protein.
The problem is that with omicron, its variant a little bit, so the neutralizing antibodies aren't quite as good a fit as they would be for the original one. I'm trying to think if I can give you an analogy. You maybe have both winter boots and dress shoes, and the dress shoes fit tighter than your winter boots, if you don't put your shoes in those boots. It's kind of the same thing: They're sloppy, the fit from the Wuhan variant vaccine with the omicron variant, and because of that, it doesn't protect you as well.
6:30 p.m.
Professor of Pediatrics (Infectious Diseases), Dalhousie University and IWK Health Centre, As an Individual
The reason that people don't want to just do an omicron variant vaccine is because we know that's not the last variant we're going to have. We want to try to be protective against that whole family. They're now working on trying to get a COVID-family vaccine that would protect you against the whole family, not just the ones we have been detecting.
6:30 p.m.
Professor of Pediatrics (Infectious Diseases), Dalhousie University and IWK Health Centre, As an Individual
The big takeaway is that we need more research money, and that means we need to give more money to CIHR and the other tri-councils.
6:30 p.m.
Liberal
The Chair Liberal Sean Casey
Okay, that's a good note on which to finish.
This has been a fascinating discussion.
6:30 p.m.
Some hon. members
Hear, hear!
6:30 p.m.
Liberal
The Chair Liberal Sean Casey
Thanks to everyone. It would be great if we could keep it going for two hours.
Thanks again for the efforts you made to be here. Thank you so much for your presentations and for your answers. It has been extremely informative for all of us. This has been an exceptional session.
Is it the will of the committee to adjourn?
6:30 p.m.
Some hon. members
Agreed.