COVID-19 Q&A: Toronto's top doctor on moving to Step 2 ahead of schedule, mixing vaccines


In her weekly segment with CP24, Dr. Eileen de Villa, Toronto's medical officer of health, answers viewer questions about COVID-19, including vaccines, variants and the latest public health measures.

CP24: Premier Doug Ford says he is discussing the possibility of moving the province into Step 2 ahead of schedule. Are you recommending that Toronto moves into Step 2 early?

De Villa: I think we do need to look very carefully at what our circumstances are. And we can see that things are definitely moving in the right direction. We've seen our case counts come down. We are seeing less by way of hospitalization and ICU admission. And on the plus side, we're seeing vaccination coverage going up. By the same token, we know that we've got that new Delta variant, more transmissible than the variant that caused our big wave three this spring. We know that there is some hint that it is giving rise to more hospitalizations, more serious infections, at least as we understand the experiences of other jurisdictions. So, it is this delicate balance. We do have a good reopening plan that's been put forward by the province. I do think that we should follow that carefully. And that we should really commit to monitoring carefully as we move forward. There's no question. We all want to reopen and get back to life as soon as possible. But I know that we all want to do this safely and in a way that doesn't see us lose the progress we've made thus far.

CP24: You must have been in discussion with the chief medical officer of health on the next step of reopening. What have those conversations been like? Are you officially recommending that Toronto enters Step 2?

De Villa: We are having some conversations for sure. At this point in time, we're still having those conversations. And I try not to engage in policy decisions through the media. But suffice it to say that I think we all want to see ourselves, not just Toronto, but the entire province of Ontario, reopen, restore activities, but to do so in a way that safe and that is science-informed.

CP24: Have you received your second dose?

De Villa: You can well imagine that I am absolutely keen on getting that second dose. I'm all booked up for next week. And again, in keeping with the interchangeability, I will take the vaccine that is available to me at the time that it's offered, knowing that it will provide me with the protection that I really want.

CP24: You have no issues with Moderna?

De Villa: No, none whatsoever.

CP24: India is reporting a new variant emerging called delta plus. What do you know about this and what are your concerns?

De Villa: I don't have specific information around delta plus here, but certainly have been looking at the reports from around the world, particularly from India, and what's happening in particular states there with the advent in the identification of delta plus, which I hear has been associated with, again, more transmissibility and the potential for more serious outcomes associated with this variant. Again, what this really speaks to is the need for us to continue to really focus on vaccination as much as possible. We've seen with the Delta variant that the current vaccines that we have available to us are really effective in terms of protection against it, but you need to have two doses on board. So as quickly as possible, we're asking people to get that first dose and as soon as they're eligible to get the second dose. That's what will protect them. It's what protects our community. And not only do we need to think about that here locally, we do need to think with a more global mindset. We need to take care of ourselves absolutely locally, nationally and internationally if we're to be successful in terms of our COVID-19 response and reducing transmission everywhere.

CP24: SickKids hospital said a small number of cases involving patients with myocarditis following vaccination. The hospital said the patients have not required admission. What do parents need to know about this? Should they be worried?

De Villa: I think that this is something that is still very much understudy. We have heard that from the United States and from other countries like Israel; they've seen what we call a safety signal. I think this is evidence really of the fact that there is a solid surveillance system looking for particular side effects or what we call adverse effects following immunization. Certainly, we expect that following immunization, the most common sorts of things that you see are things like little pain at the injection site. In some cases, you get sort of aches and pains and feeling a little unwell, but those tend to be short-lived and relatively mild. We are also, of course, always looking for other potential side effects associated with the vaccine. And this is one -- myocarditis, or inflammation of the heart muscle or inflammation of the lining around the heart, pericarditis, are the kinds of things that have been reported elsewhere. I have not heard specifically about cases. It's interesting to hear, and I'm sure we'll be in conversation with our colleagues from Sick Children, as more and more of these cases and other health care providers as these might be found. The good news is that we see that there is an effective surveillance mechanism. It's finding these cases and getting knowledge and understanding and investigating these cases. But the good news, as I understand it, is that they tend to be mild. They are treatable. The main thing is to identify symptoms. If people are feeling tightness or chest pain or abnormal heartbeat, after immunization, particularly for young people in the first few days following immunization, that's a sign to seek medical attention. Err on the side of caution. But again, treatable, manageable, and identifiable. So, good safety and surveillance mechanism in place and as long as we're aware of looking for these things, again, manageable conditions and important to continue to get vaccinated to protect against COVID-19.

CP24: A viewer says there's been no worldwide date confirming that mixing Moderna and Pfizer vaccines are safe and effective. The CDC in the United States even says that the safety and efficacy of a mixed product series have not been evaluated. Both doses of the series should be completed with the same product. The viewer asks, why is NACI telling the public that mRNA vaccines are virtually identical, and we are encouraged to take Moderna when Pfizer is not available?

De Villa: I get that nervousness. I understand that. But I will say this. NACI or the National Advisory Committee on Immunization made its recommendation based on principles of vaccinology. This is a practice that we do with other vaccines on a pretty regular basis, whether we're talking about the mumps, measles and rubella vaccines, or hepatitis vaccine or influenza vaccine. We actually substitute different vaccines in, recognizing that they essentially perform the same function. I mentioned earlier today at a press briefing that one of my colleagues at Toronto Public Health calls the two mRNA vaccines like twins. They're effectively like twins. And interestingly, one of our newspapers talked about how it's kind of like different brands of bottled water -- the same product, effectively different packaging, different producer or manufacturer, but built on the same foundation of vaccine technology. What's interesting is that there are studies going on right now to evaluate the mix and match approach. We know that other jurisdictions are using a similar mix and match approach. We know that other jurisdictions are using a similar mix and match approach. And actually, if you look at the CDC guidance, they will tell you that if there is, for example, a supply issue that it is reasonable to switch out a different mRNA vaccine in order to ensure that the vaccination is provided in a timely fashion if, for whatever reason, the product that you received as the first dose isn't available for the second. It tells you that there's a good reason to do this from a vaccine point of view and that we have every reason to believe that it should be effective, knowing that there are studies coming up to specifically evaluate this question.

CP24: Is it safe for pregnant women to mix vaccine doses, the viewer asks. She says she is 33 weeks pregnant and had Pfizer for a first dose. She says she would like to get her second dose before she gives birth, but she has not heard much about the safety of vaccine mixing for people like her.

De Villa: When it comes to the mRNA vaccines, this is the product that is recommended and vaccination I should just emphasize, again, is recommended for women who are currently pregnant and to this viewer, first of all, congratulations. Baby is coming up and it's a wonderful point in your life. And I would encourage you to enjoy every moment of it. It is reasonable. Again, these are the same. They're twins. To use the language that I've already used, it is the same vaccine technology. So essentially, the same product wrapped up in a different package. So, I would encourage appropriate vaccination. And for people who have specific questions and have unique medical circumstances, I, of course, always encourage people to have those questions addressed with their health care provider -- somebody who understands your specific circumstances in the fullness of all the details. I think that's a really important thing to do for those who have unique and special questions around their circumstances. Please go speak to a trusted health-care provider. Make sure you're getting your information from reliable sources because this is an important question. We're talking about your health and health-care. And I think that those circumstances and questions you may have should be answered by somebody who really does know your unique medical conditions and can address your specific concern.

CP24: A viewer says her kids, ages four and nine, are not eligible for vaccination yet. Would they be at risk if I send them to school in person in September, she asks. Have you heard any kids getting seriously sick due to the Delta variant?

De Villa: I have not heard of specific information around children. Certainly, we know that children are susceptible to COVID-19. My understanding is that they are obviously susceptible to the Delta variant as well. To my knowledge, there isn't a signal or information that suggests that there is significant illness or hospitalization amongst young people associated with Delta infection. We are still acquiring information from the various countries around the world that are a little bit ahead of us. But of course, we know that the vaccine manufacturers are actually doing studies right now in respect of using vaccines for those younger than 12 years of age. We hope to hear some results from them soon so that perhaps we can imagine in the not-too-distant future, seeing those younger than 12 having the opportunity to benefit from the protection of vaccines. So, fingers crossed, those studies continue to proceed. We'll look forward to hearing what the vaccine manufacturers and what our regulatory authorities have to say about those studies in the not-too-distant future.

CP24: Can you give us an update on the vaccination program for homeless people? How successful is it? Was there some vaccine hesitancy in that population?

De Villa: I would say that the program has been very successful to date. And, of course, it continues. Was there some hesitancy? I think we have seen hesitancy across the board, particularly with individuals who perhaps have had challenges with health care and have trust issues when interacting with health care providers. So, I don't think that's unexpected. But I'm pleased to say that through repeated efforts, and sometimes through multiple engagements, we have been successful in terms of getting people the vaccine, whether we're talking about clients of the shelter system, those who are homeless or are under housed themselves, as well as those who work within the system. But, again, it is important to make sure that everyone who participates in the system, whether a staffer or a client, is afforded that regular opportunity to be offered vaccine and take it up, get that first dose and then get the second dose. So, thus far, very successful. I know that we have visited shelters. We have visited drop-in sites. And yes, there were also vaccination teams that went out to the encampments to ensure that they, too, were offered the opportunity to get the protective benefits of the vaccine. And many people have taken that up. We're not done yet. We're going to continue to make sure that those who have not yet had the opportunity to get a first dose and those who need a second dose are afforded those vaccination opportunities.

CP24: What is the outbreak situation in city shelters?

De Villa: As of today, no outbreaks in the shelters at this point in time and we're going to do everything we can. And I certainly know that those who are engaged in the shelter system, the staff within the system, are doing everything they can to ensure that all the infection prevention and control measures are in place to keep it as close to zero for as long as we can. A little easier at this time of year. You can enjoy the outdoor air and be outdoors in a much lower risk environment. So, certainly taking advantage of the capacity to be outdoors, open windows, etc. Those kinds of things make a huge difference.

CP24: A viewer asks, why does the vaccine criteria at pop-up clinics seem to change daily? For example, changing from everyone in Toronto to hot spot neighbourhoods only. Isn't Toronto a hot spot right now?

De Villa: I think that from the provincial perspective, we are seen as an area where there is delta variant and, in that regard, perhaps the entire city is seen as a hotspot. And we certainly want everyone in the city to be afforded that opportunity to get the vaccination because we know it's really important. But there are certainly areas of the city that have seen more COVID-19 activity than others and continue to see more COVID-19 activity as well. There are parts of the city where the coverage rate is not as high as we would like it to be and where access we know is just going to be more challenging. So, we do see some of the pop-up and mobile clinics trying to focus efforts on those areas of the city that either have been higher risk in terms of infection and or higher risk in terms of vaccination coverage rates. We're trying to focus some efforts there. But there's no question we want everybody in the city to be vaccinated and we're trying to facilitate access to the vaccine to all residents of Toronto.

CP24: Final thoughts for this week?

De Villa: I would actually just ask that people continue to do all the good things that they've been doing for the last several months. Continue to practice those self-protection measures. We still do need to be careful, but of course, it's summer. So, we have this wonderful opportunity to be able to be outside where we know the risk is definitely lower. And for those who haven't yet gotten vaccinated, please do get vaccinated. It's the best thing we can do to protect ourselves and to protect our community and to everybody. If you know people who haven't been vaccinated, help them, talk to them about why you got vaccinated and the benefits of vaccination. And of course, I would just ask that people rely on good sources, credible sources of information.