Health Committee on March 7th, 2016

[Matthew Gilmour]

Yes, there's a multitude of companies and other institutes across the world that are pursuing a Zika vaccine right now. Part of our team that was responsible for the Ebola vaccine, which was of great assistance in west Africa for the outbreak there, is part of an American consortium that is pursuing a DNA-based Zika vaccine. At this point it's still a candidate. It's not something that's promised to be effective and safe, but they've moved it along the development pipeline quite a bit. They want to start phase one clinical trials as their next step. That would be to show elements of safety and efficacy.

There's a large global interest in developing a vaccine for Zika. It's unlike the Ebola vaccine, where we're personally and formally pursuing that kind of answer. With Zika we're just participating with our global partners where we can. Part of our contribution is the team that's been part of the consortium to develop one of the candidates for Zika that's now under consideration.

[Colin Carrie, Conservative, Oshawa, ON]

Excellent. Thank you very much.

Dr. Sher, you mentioned the pathogen inactivation technology. I think you made a comment that sitting right next to you, to your right, is one of the world leaders on that. For some reason it's not licensed for availability in Canada. Could you elaborate a bit on why it's not licensed? Do you have funds for it? What's going on? Is it that the regulatory approach is difficult to get through? Could you give us an update on that?

[Dr. Dana Devine]

Sure, I'd be happy to. There are two companies that are seeking licensure for their pathogen inactivation technologies in Canada. One of them is the first company that got into the business, and it has been selling products for treatment in blood mostly in Europe initially, but globally at this point. They have enough experience with their technology that they could put a request before Health Canada for approval to market in this country with the experience base they had previously.

The other company is the second one in that came to marketing approvals in Europe about seven years after the first company, so it has less experience. In discussions with Health Canada, this second company was asked to acquire additional clinical experience. Canadian Blood Services has been involved with that company by assisting in doing a clinical trial for the treatment of platelet products with these pathogen inactivation technologies, and we have a trial running in several hospitals in Ontario that should be completed in May.

We do anticipate that marketing approvals will be granted to these two companies some time within the next 24 months, and then we'll have the opportunity to look at implementation in Canada.

[Colin Carrie, Conservative, Oshawa, ON]

How would that help Canadians who are concerned about Zika?

[Dr. Dana Devine]

These two technologies are very good at killing the viruses that are all of the Zika first cousins. In the preliminary studies that have been done on laboratory strains of the Zika virus, including the Thai strain that my colleagues from PHAC have been talking about, these two technologies killed the Zika virus. We are anticipating that this is a way of sterilizing blood and blood products.

The challenge for us is that the technologies that have been developed can only be used on platelets and on plasma. We don't have a technology for red cells. There are two technologies that are in clinical trials. We think that they're coming, but they're not here yet.

If you were talking about giving a red blood cell transfusion to a pregnant woman, you would not be able to reduce the Zika risk by the pathogen inactivation technologies quite yet, but we do see that coming in the near future.

[Dr. Graham Sher]

If I may I'll add to that question because I think this is an important message for the committee, and I will reiterate what I said in my remarks that Canadian Blood Services has gone on the public record as saying that pathogen reduction technology is the next paradigm in blood safety and as soon as these technologies are appropriately licensed we will be developing the plans to implement them. Given the limitations Dr. Devine has described initially it will be there for platelets and not for red cells.

We do believe this is a paradigm shift because it allows us to deal not just with the agents that we know and are concerned about today—HIV, hepatitis B, hepatitis C—but it also allows us to deal with the next Zika as it emerges and we will already be in a defensive position because we will have had this technology in place.

You're not always chasing your tail from a testing point of view, which is precisely the challenge we face. Today it's Zika. Yesterday, it was chikungunya. The day before, it was dengue virus. These technologies take a much broader approach.

[Colin Carrie, Conservative, Oshawa, ON]

That's great technology. Thanks for introducing me to it. I've never heard of it before, but hopefully it's something the government can move forward on and help expedite. That would be great.

Thank you.

[The Chair, Liberal, Bill Casey]

Mr. Ayoub.

[Ramez Ayoub, Liberal, Thérèse-De Blainville, QC]

Thank you, Mr. Chair.

I would like to thank the witnesses for joining us today. I'm going to ask my questions in French, if you don't mind.

The witnesses have answered a number of questions. Dr. Taylor, I'd like you to elaborate on what you were saying earlier. You were talking about the incubation period and transmission of the virus. Returning travellers need to wait a certain amount of time before having sex, specifically a certain number of days.

What I'm particularly concerned about is sexual transmission of the virus. A pregnant woman could become infected by a man who has returned from a trip and is carrying the virus. I understood that, when coming back from a trip, a couple where the woman is pregnant should not have unprotected sex for the entire pregnancy. Is that correct? Is it for just 28 days, or is it really for the entire pregnancy?

[Dr. Gregory Taylor]

That's a very good question. Thanks for clarifying that if I wasn't clear.

The recommendations that came from CATMAT, the experts we brought together, were that men coming back should use condoms for a two-month period if they're having sex with somebody who could get pregnant. That's being very careful, and that's based on the fact that we think it's about two weeks, but there may be evidence that there's virus in the semen for longer than that. So that's being extra cautious.

The “entire pregnancy” targeted to men meant that if they were coming back and they were having sex with someone who was pregnant they should then wear a condom for the duration of the pregnancy. Again, this is being extra cautious because there is evidence suggesting that even in the third trimester it could have an effect.

Those will change as we know more information about how long the virus lives in the semen, but that was the basis of that.

Thank you for the clarity.

[Ramez Ayoub, Liberal, Thérèse-De Blainville, QC]

If I understand correctly, then, it is not known how long the virus stays in the semen. Is that right?

[Dr. Gregory Taylor]

No, we don't, not yet. We're learning.

As I said, science so far tells us two weeks, but it may be longer. We don't know.

[Ramez Ayoub, Liberal, Thérèse-De Blainville, QC]

Okay.

What are the origins of the Zika virus in Canada? From what I see in the information, the virus was discovered in Uganda in the 1950s.

Why are we talking about it now? How did Zika suddenly become so prevalent?

[Dr. Gregory Taylor]

That's another excellent question.

The Zika virus originated in Africa and in Asia. As you mentioned it was first detected there in 1947, but it was not in the Americas. This virus is a slightly different strain. I believe the genetic similarity is about 99% or 98%.

In the Americas you have people who have never been infected before so there is no immunity. In Africa and Asia people have been infected on an ongoing basis, don't know they're infected, and develop an immunity, but we have a naive—that's the technical term—population in the Americas who have never been infected.

The theory or some of the theories we have is that an infected individual—French Polynesia I think was one of the first places—came to the Americas, potentially Brazil, and got bitten by a mosquito and then infected somebody else and then it just blew up. Literally, millions and millions of people are infected in the Americas right now.

Why it blew up so quickly probably has to do with the slight variation. We don't know if there's an animal reservoir of some sort, a lot of viruses like Ebola have animal reservoirs. However, at this point the theories are that it's a naive population and there's no inherent immunity. That's why it's spreading so quickly.

[Ramez Ayoub, Liberal, Thérèse-De Blainville, QC]

Now I'd like to ask a more technical question.

How do you track the spread of the Zika virus in Canada? What method do you use to monitor that?

[Dr. Gregory Taylor]

That again is a good question. It's difficult. If you don't look for it, you don't know if a person has it. I would suspect the vast majority of people in Canada who are infected will come back from having travelled with no symptoms or with mild symptoms and they won't get tested. We won't know about them.

The only time we know if someone has Zika is when blood goes to Matt's lab and we find the virus present in the blood or there's a suggestion from their antibodies that someone has it. That's all. So far, as I mentioned, 20 people in Canada have tested positive. I'm confident and I'm sure the numbers are much higher than that, but the only way we can detect it is if we test people.

[Ramez Ayoub, Liberal, Thérèse-De Blainville, QC]

Very good. Thank you.

[The Chair, Liberal, Bill Casey]

Mr. Kmiec, you're up.

[Tom Kmiec, Conservative, Calgary Shepard, AB]

Thank you very much, all of you, for your presentations so far.

Actually, the question I was going to ask is on organ donation, mostly because it's an area of personal interest for me. You said that so far no one has been denied an organ donation because of this, but you did talk about the case of stem cells.

We've heard that there might be larger cases or other cases in which we don't know someone has Zika, and they don't know either. What is the risk? Is there a potential that somebody might be refused a donation in the future, whether of an organ or a product like a stem cell or a bone graft or something else that they would be asking for? When it would come to that moment, you said that physicians could say they were going to continue on. I'm guessing they would involve the patient when making that decision. Can you talk about that a little bit more?

[Dr. Graham Sher]

I'd like to. Thank you for that question.

I'm going to make a general comment, and then Dr. Devine can provide a little bit more of the specifics. I think it is important for committee members to appreciate that the clinical decision-making to support an organ donation or a stem cell transplant is very different from the clinical decision-making to give somebody a transfusion.

We collect close to a million units of blood a year. About 1.5 million transfusion events happen in Canada every year, and if a physician needs to choose a unit of blood, typically there's a large selection to choose from, so we can easily defer 3% of the blood donors and still meet the needs of all the transfusion patients.

For stem cell donors and patients, and certainly for organ transplant patients and donors, there's a very different relationship. Getting the organ is a life-saving event and often it's the only organ available, and if the patient doesn't get it, he or she might well die from the underlying disease. The whole notions of risk-based decision-making and clinical decision-making are very different.

I'll let Dr. Devine clarify again the situation with the stem cell donor, but if an organ donor who may have travelled to one of the Zika-risk countries comes back to Canada and is, unfortunately, killed in a motor vehicle accident within that 21-day window, the physician will make a clinical decision as to whether that organ is potentially going to save a life at the risk and very low likelihood of transmitting Zika, probably in the order of one in three million or four million.

The set of risk-based decisions for organs and stem cells is very different from that for blood, and it is based purely on the availability of the resource to match the patient's needs. Again, I think we'll clarify for the committee the specifics on that stem cell case.

[Dr. Dana Devine]

The other thing I'd like to add to this is that I think we need to remember that the one really at risk of Zika virus infection is the fetus. We know that for the walking adult, it's a very mild illness, and most people who get it don't even know they have it.

From the perspective of making a clinical decision about transplanting an organ that potentially came from a donor who might have had a holiday in Cancun before they ended up being an organ donor or someone in the stem cell arena, we're not giving stem cell transplants or organ transplants to pregnant ladies, so there's a completely different set of clinical decisions that are made in that framework.

In terms of the actual concern over stem cell donors, we had the case I referred to, which you may have heard of through other avenues. It came up during the time before we had put the deferral in place.

Now that we have that deferral, we are communicating with all of our donors who are in the evaluation phase for possibly becoming stem cell donors. They've been identified as first-level matches or preliminary matches, and we start right up front by telling them that if they have any travel plans, they shouldn't go to any of these risk areas because doing so will preclude them from being donors.

I don't see that that's actually going to be a particular problem for the Canadian transplant centres.

[The Chair, Liberal, Bill Casey]

You have just a little time.

[Tom Kmiec, Conservative, Calgary Shepard, AB]

Maybe I'll change pace.

On the international reaction from the countries where there is Zika, could you talk a little more about whether any countries have been way more restrictive or have put more controls on both blood donations and organ donations, or on travel? Have any countries banned travel for people who are coming from affected regions?

[Dr. Dana Devine]

I can't speak to the travel ban, but I can speak to the blood donation ban.

Most other countries are using a 28-day deferral. This is based on the fact that the original risk calculation assessments were done by an American group, and they assessed only 14 days and 28 days. When you do the calculations for 14 days, you realize that it might not be long enough, so while we're trying to understand more about the Zika virus and really apply the precautionary principle, they said to go with the 28 days, that it looks like it's probably safer until we understand more.

Canada did something a bit different. We said that what the Americans have done is very nice, but we wanted to do a Canadian calculation that's relevant to where blood donors travel from Canada and to what our risks are in this country. We had the ability to look at 14 days, 21 days, and 28 days, because those are three marks we can put in our computer system that are already there. We don't have to redesign a computer system to bring in that deferral. When we did those calculations, we realized that the deferral of 21 days was adequately protective, and it was just as good as the 28-day deferral. We went with the shorter deferral because it was less impactful on the blood supply.

[The Chair, Liberal, Bill Casey]

Thank you.

Did the 14-, 21-, and 28-day deferral only depend on the person self-identifying that they'd been in an area? How confident are you that people self-identify?