Health Committee on May 25th, 2020

[Dr. Caroline Quach-Thanh]

Even though the epidemic seemed to have hit New York City pretty hard, I think the percentage of the prevalence wasn't that high. Again, if we're looking to reach 70%, it's not happening any time soon. Also, I think Canada is even further down, so we haven't seen anything yet and are still very much at risk for a second wave.

[Robert Gordon Kitchen, Conservative, Souris—Moose Mountain, SK]

Thank you very much. I appreciate that.

Dr. Quach-Thanh, I was reading about your research support. I'm going to ask you a specific question. I notice that the title of one of the studies you're doing is “Influenza Immunization for all Canadians: Does One Size Fit All?” I realize that the study goes to the end of this month of 2020, but is there anything you could share on that which might be of interest for us to understand?

[Dr. Caroline Quach-Thanh]

Well, I can tell you that getting data is like pulling teeth out of a mouth, so we're delayed, because the data-sharing hasn't been easy. However, the goal of that study is to look at the differential response to a vaccine in males and females. Our basic hypothesis is that females will answer better and will have better immune response but may also have more adverse events in terms of local adverse events. It just goes hand in hand. The goal was to look at clinical trials that have been done in the past and reanalyze the data on males versus females. As I said, we're having a hard time getting to those data, but it will come.

[Robert Gordon Kitchen, Conservative, Souris—Moose Mountain, SK]

Do you see where there might be some potential for a future hypothesis on whether this might relate to COVID?

[Dr. Caroline Quach-Thanh]

When we look at the first data out, males seem to have more mortality than females, which could also mean that their immune response might not be as strong, but it's very early on. Because we don't have a good denominator, those proportions are always hard to interpret.

It's something interesting to see. The male versus female response to infectious diseases is not the same. A man's cold is actually something that seems to exist.

[Robert Gordon Kitchen, Conservative, Souris—Moose Mountain, SK]

Thank you.

[The Chair, Liberal, Ron McKinnon]

Dr. Powlowski, please go ahead for five minutes.

[Marcus Powlowski, Liberal, Thunder Bay—Rainy River, ON]

This has been going on for a while. In China it started in late December or early January, and I don't know when it hit Italy, February or March. It's been around for a number of months.

There are a number of randomized control trials in Canada. I think these started a lot earlier in places like England. I don't know whether Italy had them, but there are some treatments that sound pretty good on paper. I'll ask Dr. Mossman, because I think she's involved with the use of convalescent serum. Also, remdesivir has been touted by some people in the United States as being a big cure.

If a study is going really well and has shown that one of the treatments is clearly beneficial, and it becomes unethical to continue that study, but all these studies are still going on months later, I'm thinking—I may be wrong—there doesn't seem to be any clear benefit to [Technical difficulty—Editor]

[The Chair, Liberal, Ron McKinnon]

Dr. Powlowski, you're on mute. I don't think I heard your question.

[Marcus Powlowski, Liberal, Thunder Bay—Rainy River, ON]

Given that there have been randomized control trials probably for over a month—a couple of months in places like England—yet none of them have been ended prematurely because there has been a clear finding of efficacy, can we conclude from those studies that there's no great cure out there among the existing treatments?

[Dr. Karen Mossman]

My understanding of the data that's emerging, for example from the study in the States on remdesivir, is that it's okay. It has some efficacy, but certainly, what we know from other viral infections is that, with a single agent as an antiviral, often even with some efficacy, the virus will quickly mutate around that.

I think as we understand what cocktails we can use, similar to how we've used cocktails for HIV, even if each individual antiviral drug is okay and not spectacular, a cocktail approach is often very useful.

As for convalescent serum, I understand there are a number of studies or instances where they've used convalescent serum and seen some efficacy. Certainly, at McMaster and across Canada there's a new study starting called the CONCOR-1 study, which is in more than 60 hospitals. They're specifically going to have sufficient power to be able to really understand the convalescent serum, and along with that, they will also be looking at the levels of the antibodies and trying to understand, not just if there are antibodies, but at what levels and how efficacious they are so that we can better understand if it does work, why it's working and how it works.

[Marcus Powlowski, Liberal, Thunder Bay—Rainy River, ON]

I think one of the big conundrums with this disease is why children don't seem to be affected very much. There's talk about this being an etiological factor in Kawasaki disease, but that seems unclear at the moment. It seems like a really interesting question why they're not infected, or when they get infections, why they don't seem to get really sick.

Is there any possibility that having had another coronavirus recently protects you from a different kind of coronavirus? We know that coronavirus is a fairly common cause of the simple cold. Is there any cross-protection from one form of coronavirus to another?

[Dr. Karen Mossman]

There have been some studies that have looked at that, and there are certainly some studies now looking at patients who were infected with the original SARS, so SARS-CoV-1. Again, in those studies the immunity lasts really only for two to three years, so even though there are potentially some low levels of protection, coronaviruses don't generate historically long-lasting protection.

Children have a very high natural immunity. Their immune system is often quite active, whereas that wanes as they get older, so part of the reason children and young adults aren't getting as severely ill could be that they have the most robust and natural or innate immune response.

[The Chair, Liberal, Ron McKinnon]

Thank you.

Mr. Desilets, please go ahead for two and a half minutes.

[Luc Desilets, Bloc, Rivière-des-Mille-Îles, QC]

Thank you, Mr. Chair.

I'd like to thank the witnesses for their informative and fascinating remarks. It makes me want to be a student again and go to medical school, something to keep in mind should the voters decide they've had enough of me.

My question is for you, Ms. Quach-Thanh.

We've heard a lot about the challenges around information-sharing and collecting epidemiological data. Which agency or individual in Canada do you think should be responsible for that? Who does that fall to?

[Dr. Caroline Quach-Thanh]

That's a broad question that I don't have the answer to. If I did, I would have said it by now. That said, my sense is that the Public Health Agency of Canada definitely has a role to play, and I think it's trying to do that. The fact remains, however, that, at the provincial level, data also belong to the provinces.

I know all the parties have tried to reach agreements in the past, including the multi-lateral information sharing agreement, or MLISA for short. It doesn't seem to allow for data transfer, at least not in real time. Eventually they are transferred, but not until they've been validated, often nearly a year later. I'm not well versed enough in Canada's Constitution to say how a direct transfer should work. All I can tell you is that it doesn't work for those of us on the receiving end.

[Luc Desilets, Bloc, Rivière-des-Mille-Îles, QC]

Some sort of strategy is warranted, then. We've been told that repeatedly. You, too, seem to think that's important.

Montreal is in a pretty unique situation, Do you think it's at greater risk of being hit by a second wave, or peak, of COVID-19?

[Dr. Caroline Quach-Thanh]

What we all fear is that the second peak will hit quickly. If the lockdown isn't lifted in the right way, meaning, we follow the example of some of the southern states—Texas, Georgia and Alabama, where the number of cases has started to climb back up—and if people don't continue to wear masks and respect physical distancing guidelines, the number of cases could start rising again.

Testing is very important, but the public absolutely must abide by the recommendations. We shall see what happens.

[Luc Desilets, Bloc, Rivière-des-Mille-Îles, QC]

If I ask Dr. Tremblay—

[The Chair, Liberal, Ron McKinnon]

Thank you, Mr. Desilets.

[Luc Desilets, Bloc, Rivière-des-Mille-Îles, QC]

Very well.

Thank you very much.

[The Chair, Liberal, Ron McKinnon]

Mr. Davies, please go ahead for two and a half minutes.

[Don Davies, NDP, Vancouver Kingsway, BC]

Thank you.

Dr. Quach-Thanh, you have stated that a challenge trial is what will give, from a scientific point of view, the quickest answers to all kinds of questions, whether on the effectiveness of a vaccine or the risk of reinfection or what the immune response is.

Could you briefly tell us what a challenge trial is and where Canada is at with respect to conducting them?

[Dr. Caroline Quach-Thanh]

In opposition to a regular randomized controlled trial, in which you would vaccinate a patient and wait for that person to be exposed to the disease to see whether the vaccine would be then protective, in a challenge trial you actually squirt the virus directly into the nose of a person who's been either vaccinated or not, to see if those who are vaccinated are more protected than those who are not.

We haven't done any challenge trials in Canada thus far with any virus, but two challenge units have been built as part of a CFI, one in Dalhousie, where they are doing that first phase one study, and one at the MUHC in Montreal. Those challenge units were built to do studies on influenza vaccines after vaccination, but there haven't been any. I think that to do a challenge trial, you would need to be in at least phase two or three of a vaccine, because before that you would still be studying the safety of the vaccine and its immunogenicity, but instead of vaccinating and then just letting people be and hoping that they would be exposed soon enough to see whether that vaccine works, you would have a challenge trial.

They've also done that for norovirus vaccines.

[Don Davies, NDP, Vancouver Kingsway, BC]

Do you know whether anybody in the world is using a challenge trial process right now?