Evidence of meeting #24 for Health in the 43rd Parliament, 2nd Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was naci.
A recording is available from Parliament.
Liberal
Marcus Powlowski Liberal Thunder Bay—Rainy River, ON
Is the updated data from the Lancet study, or is there some other data supporting the use in people over 65?
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
There are two Public Health England publications. I can't remember exactly what journals they were in. Those two studies are being added to the corpus of the evidence. They are all real-world effectiveness. We do not have new efficacy data. These will come out when the U.S. trial is looked at, which should come sometime in April.
Liberal
Marcus Powlowski Liberal Thunder Bay—Rainy River, ON
To reiterate, the effectiveness is actually the more impressive number. It's the better number.
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
Liberal
Marcus Powlowski Liberal Thunder Bay—Rainy River, ON
We would have thought it would have been the other way around, that the efficiency would be higher.
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
Correct.
Liberal
Marcus Powlowski Liberal Thunder Bay—Rainy River, ON
I think when you actually look at the numbers for AstraZeneca, it's really not too bad.
I also I want to ask you about the Scottish study. I think that's based on the NIH, which automatically has data collection. To my understanding, in that, over 400,000 people, many of them in their eighties, got AstraZeneca, and they were reporting a 94% reduction in hospitalization. Now, I realize that you said that if you look at the data, they were reporting a pretty significant reduction in hospitalization in the first few weeks, which doesn't make much sense immunologically. However, when you look at the total number, 400,000, that's a pretty well-powered study—
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
I wasn't talking about power. The problem is that there is a bias in the study because the people who were vaccinated were very different from those who weren't. Not being able to explain this 70%-something effectiveness in the first two weeks following vaccination in terms of decrease in hospitalization just makes one wonder what the problem with that study is.
We have better studies. Based on just that study, we didn't feel comfortable changing our recommendation at that point in time.
Liberal
The Chair Liberal Ron McKinnon
Thank you, Dr. Powlowski.
Mr. Thériault, you have the floor for two and a half minutes.
Bloc
Luc Thériault Bloc Montcalm, QC
My first question will be brief, and the second will be about methodology.
Dr. Berthiaume, to retain people's confidence in the vaccination process, would it not be better to be proactive, given that there is no connection between not being proactive and the fact that 300,000 doses of AstraZeneca will expire on April 2?
Would it not be better to just suspend vaccination with the AstraZeneca vaccine until we have the full story on what's happening in Denmark and Norway? That would take a few days or a week at the most, in my opinion.
Director, Bureau of Medical Sciences, Therapeutic Products Directorate, Health Products and Food Branch, Department of Health
Thank you for your question.
This evening, Health Canada issued an advisory to say that it currently has no safety concerns with Canadian doses.
In Europe, they are investigating, but several advisories they have issued say that the side effects were probably not related to the vaccination. Currently, it's likely that the events are related to the effects seen in the general population and not to the vaccination. However, that remains to be confirmed.
At this time, it would be premature to go ahead and stop vaccination based on the current data.
Bloc
Director, Bureau of Medical Sciences, Therapeutic Products Directorate, Health Products and Food Branch, Department of Health
Based on the data we have, I believe there are 30 cases out of 20 million doses. I would have to look at the numbers again. However, we already know that this number of cases is well below the normal incidence of these pathologies.
Those cases are linked in time, but not in causality.
Bloc
Luc Thériault Bloc Montcalm, QC
So you're saying that those countries suspended the use of the vaccine for nothing, and that, if we had the same data, we would have no reason to suspend vaccination here in Canada.
Director, Bureau of Medical Sciences, Therapeutic Products Directorate, Health Products and Food Branch, Department of Health
Europe has not reached a consensus on suspension. In the United Kingdom, where the vaccine is most widely used, they have decided not to suspend the use of the vaccine.
Bloc
Luc Thériault Bloc Montcalm, QC
Thank you very much.
Dr. Quach-Thanh, in response 3 that you sent us today, you state the following:
At present, there is uncertainty as to the degree to which the vaccines prevent people from acquiring the infection...
Later, you add:
Until such data is available, modellers are not in a position to estimate the proportion of the population needed to vaccinate to reduce R below 1...or to compare between vaccines in their capacities to do so.
Can you explain to me how you plan to compile data on the vaccines administered so that, for example, you can compare their capacity to deal with variants?
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
I will try to answer your question. I'm not convinced that I fully understood it.
In terms of asymptomatic infections, that data is being collected in various studies. We know that, for AstraZeneca, which looked at this factor when the other companies did not—we will at least give them that—the efficacy from the standpoint of decreasing asymptomatic infections was not good. The other companies did not study this factor, so that may be the case for them as well.
In terms of variants, no link has been established between an asymptomatic infection and a variant. Currently, several ways are being used to find out if a vaccine works against a variant or not. We have in vitro methods. After vaccinating a person, we take their antibodies to see if they are able to neutralize the variant virus. In addition, we look to see if the person's cellular immunity has any effect on the variant.
The other way is to do vaccine effectiveness studies. They involve determining how many infections the vaccine is able to prevent from a variant, compared to when there is no variant.
In their phase 3 studies, AstraZeneca and Johnson & Johnson struggled with the South African and United Kingdom variants. So they sometimes have somewhat lower vaccine efficacy rates than Pfizer and Moderna, who did their studies much earlier, before the variants emerged. You have to take that into account in the data analysis as well.
As to how the current data can be used to determine whether or not we're able to control the variants, it's really possible by monitoring vaccine effectiveness in the population.
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
They have already been compiled—
Liberal
The Chair Liberal Ron McKinnon
Thank you, Mr. Thériault.
We go now to Mr. Davies.
Mr. Thériault got a bit of extra time, so we'll extend yours as well. Go ahead, please.
NDP
Don Davies NDP Vancouver Kingsway, BC
Thank you.
Dr. Quach-Thanh, NACI has previously recommended that adults over 70 years of age should be prioritized in the first phase of vaccine rollout across Canada, but we know that many seniors over 70 have not been vaccinated yet. NACI also said that efforts should be made to complete that stage before proceeding to any subsequent stage as vaccine supply increases.
In your view, how should the provinces and territories prioritize administration of the AstraZeneca vaccine in light of NACI's recent recommendation against use in adults 65 and older?
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
At this point, based on our recommendation from March 1—because nothing else has been issued since; it's still in the works—provinces and territories still have the ability to decide what they want, but what we had said was to try to use that vaccine in people up to 64 years of age. If some provinces decide to use the vaccine in the elderly, it's absolutely up to them. I know that Quebec has decided to use it because they have looked at the newer data, the real-world effectiveness data, and therefore have decided that it was acceptable to use that vaccine.
As I said, things are moving; you will have an updated recommendation within the next few days.
NDP
Don Davies NDP Vancouver Kingsway, BC
We already heard that Canada is the only country in the world that is permitting the duration for the second shot to be up to four months. Does the fact that we're alone among all the countries in the world give you any discomfort?
Chair, National Advisory Committee on Immunization and Professor, Université de Montréal
As I said before, I would have preferred to be within the label. However, what we decided to do here—given the doses we had and the at-risk population we had—was to try to give that first dose to as many people as possible.
NDP
Don Davies NDP Vancouver Kingsway, BC
With respect, I heard that, but the issue is that many other countries are in the exact same position and they have not taken that step. We stand alone in this one area.