Toronto Public Health is monitoring the COVID-19 variant that first originated in India as it continues to surge rapidly in other countries, the city’s top doctor says.

Dr. Eileen de Villa, the medical officer of health for Toronto, reported Wednesday that there are 68 confirmed cases of the B.1.617 variant, which is now known as the Delta variant.

She said TPH is keeping an eye on the variant due to rising cases in the United Kingdom.

“Like any virus, it spreads amongst the unprotected–but this variant is showing some capability for infecting even those who are fully vaccinated, albeit generally with a milder illness,” de Villa said.

“The main message for us to draw from this is this: get vaccinated and remember that for now, it’s still really important to be mindful of the distance between yourself and others, to wear your mask when you can’t keep six feet apart, to do what you can to establish good ventilation indoors and to spend as much outside if in the company of individuals outside your household.”

READ MORE: Toronto's top doctor expresses concern with vaccination rates among residents 80 plus

Dr. Lawrence Loh, Peel’s medical officer of health, said Wednesday that the variant would become the dominant strain in the region.

“Preliminary analysis from the science table suggests that in one month, the Delta variant will be the dominant strain in our region with the rest of Ontario weeks behind,” Loh said.

Dr. de Villa joined CP24 to answer COVID-19-related questions, including the province’s decision to close schools until September, the Delta (B.1.617) variant and vaccines.

CP24: The province announced that schools would not reopen to in-person learning until September. You sent a letter to the government last week, hoping that they would open schools this month. What do you think about this decision?

De Villa: I think you're going to get opinions across the board, and the way I see it, the province has made their decision in this regard. My thinking is, now that the decision is made, the best thing that all of us can do, and I do mean this as a community, is that we all need to work together to make sure that we have circumstances for the strongest, most seamless return to school in September. It means we need to keep transmission rates of COVID-19 low. That means continuing to keep our distance and continue to practice good measures for self-protection. Wear your mask. And of course, at this point in time, if you haven't gotten your first dose of vaccine, do get that first dose of the vaccine. And when it's your turn to get a second dose of vaccine, please make sure you go ahead and get that second dose of vaccine. If we do this together and let our education partners do what they need to do within the school environment, that's what we can work together -- towards a strong and seamless return to school in September.

READ MORE: Ontario schools will not return to in-person learning in June: Premier Ford

CP24: What can kids do for their mental and physical well-being now that schools will be closed for months?

De Villa: There's no question that we all should be trying to take advantage of the nicer months while they're here. One, the nice weather is here for such a fleeting period of time. But two, it allows for that opportunity to spend more time outdoors, which we know from a COVID-19 perspective, is just a lot safer. The risk of transmitting COVID-19 in an outdoor setting is definitely significantly reduced. But for now, the current advice is still, as much as possible, to keep your distance, and for those circumstances where you can't, that's the time to make sure that you're using your mask. And, of course, get your vaccine. But outdoors, definitely lower risk. So do take advantage of the nice weather. And of course, there are health advantages to being out in nature as well. There are lots of reasons to be out there -- physical health, mental health. It's just a good thing at this time of year.

CP24: Ford talked about the threat of the Delta variant as one of the reasons why he decided to keep schools closed. How concerned are you about this variant?

De Villa: There is certainly reason to be concerned and to be watching this very carefully. And that's one of the things that those of us who work in the realm of public health are absolutely doing. This Delta variant or B.1.617 was that variant that was first identified in India. It is certainly something that we're seeing spread rapidly in countries around the world, most notably the United Kingdom. So, we're watching circumstances there. We know we have cases here in Toronto. There is a strong potential for it to be the dominant strain. With respect to timing, I don't know that anybody knows for sure. But certainly, we should be watching for that. So, for now, again, it is still COVID-19. We know how it transmits. So, maintaining that distance using your mask -- all those good measures for self-protection we've talked about for months, continue to be mainstays, but now we have the additional protection that's afforded by vaccines. So again, I can't say enough how important it is the combination of those self-protection measures and vaccines. That and getting fully vaccinated as your turn comes up, that's a really potent combination that we have available to us to protect ourselves and to protect everyone around us.

CP24: In April, the variants were winning the race against the vaccine. How about now? Which has the advantage in the race?

De Villa: We're doing well. We've got 70 per cent of our 18+ population here in the city of Toronto with at least one dose of vaccine on board. But there are pockets. We know that there are still significant proportions of our population that need to get that first dose on board. And as those first doses come on board, we want to continue to make sure that people get fully vaccinated and get that second dose. We will do everything we can to push that level as high as we can get it because that's really a major source of protection. And I'd like to see Toronto really being a leader not only in the country but, frankly, around the world when it comes to vaccine uptake. It's the best thing we can do to help take advantage of the science that's available to us to protect ourselves and our entire community.

CP24: With more vaccines coming to the province in the next few weeks, do you see the interval between first and second doses to be shortened further?

De Villa: I don't know if I can speak to significant dropping, but it's all a question of supply right now. The more supply becomes available, you have opportunities to do you know different things in respect of second dose timing, wanting to maintain that distance -- the minimum distance between that first dose and second dose. Just a reminder, though, for people that it is quite common within vaccines to find that a slightly longer period between that first dose and second dose does actually allow for greater protection. It's just the way that vaccine works with the body. Your body has that opportunity to develop that first level of protection from the first dose of the vaccine. That second dose is kind of a reinforcer or a strengthener. And the more time there is for that first dose to actually get really solidified, the stronger reinforcement or boosting effect from that second dose. So I would encourage people to get the second dose when they become available for it. I know that our federal partners are trying to get as much supply as they can as quickly as they can.

CP24: A viewer wants to know your thoughts on how safe school reopening are is.

De Villa: My sincere hope is that given that school looks like it's going to be opening in the fall that we should have lots of time to make sure that school reopening is not only safe but is incredibly smooth and seamless. I think there should be lots of work being done by our partners in education. Our part is to do what we can to keep the transmission of COVID-19 as low as we can by practicing those good self-protection measures and, of course, getting the vaccine, both our first doses and our second doses, as soon as we can.

CP24: A member of a Toronto BIA wants to know if restaurants will be able to host live entertainment and music on the patios to help enhance the outdoor dining experience.

De Villa: I don't think there's any question that we would all love to see that vibrancy back in our city. It adds a whole different dimension and a really positive dimension when you have live music and entertainment as part of your cultural fabric. No question that we want to see that happen. The province has put out its reopening plan, and it's staged very carefully in concert with vaccine uptake and a number of other public health indicators. That's probably the best I can explain their plan in a brief capsule. But the hope is that if we continue to keep transmission rates down and get vaccination rates up, we start to resume more and more aspects of life like they were before there was a COVID-19 and hopefully that includes things like music and entertainment and the things that make you know life more fun.

CP24: A viewer says she had the AstraZeneca vaccine as her first dose. She wants to know whether mixing vaccines will boost a person's immunity. She also wants to what vaccine she should get for her second dose.

De Villa: There are still some questions that science has yet to fully answer. But what I can say to the viewer is that the National Advisory Committee on Immunization, which is the official federal body that provides guidance on how best to use vaccines in Canada, has, as of yesterday, made its recommendation that for those who have received AstraZeneca as their first dose, that it is reasonable for them to get either a Pfizer or Moderna, mRNA vaccines as their second dose. It's safe and it's deemed to be a complete course of vaccination. I think that really fully understanding what makes the most sense and how much stronger or what the differences between a straight-up AstraZeneca dose one and dose two versus AstraZeneca and an mRNA vaccine as the second dose has yet to be really fleshed out as more and more of the vaccine is offered in these different combinations. But certainly, NACI has weighed in and given its advice on this. We now just have to wait and see what the provincial policy is in response to that advice. But at least we know where the official advice is from a scientific perspective.

READ MORE: Canada says it is OK to follow up first dose of AstraZeneca vaccine with Pfizer or Moderna

CP24: Another viewer who got the AstraZeneca vaccine for a first dose wants to know if the interval between two doses changes when they get the Pfizer or Moderna vaccine as their second dose.

De Villa: As I understand it, at least four weeks after the first dose of AstraZeneca. And that's currently where it stands. And as we talked about, the interval between the two doses of vaccine has been extended in Canada to as long as 16 weeks. But as we're seeing as more supply becomes available, accelerated second doses now become an opportunity or a possibility. But those minimum spaces must be maintained. That's really what's key here. There's a minimum spacing that has to be respected between the first dose and the second dose of the vaccine. And depending on the product, it's somewhere between 21 and 28 days in most cases.

CP24: Dr. Isaac Bogoch tweeted, "Why are patios closed in the first place? We know the risk of outdoor transmission is negligible & we've known this for a while. Schools are complex. I would have granted local MOH capacity to decide given heterogenous burden of COVID in ON & different needs of communities." What do you think of this?

De Villa: I think what Dr. Bogoch is getting at there is the fact that the outdoor environment is generally safer, much, much safer compared to an indoor environment. I don't think there's any question around that. What is at issue here is that the regulations and what can be opened or what needs to be closed are actually governed by provincial legislation and regulation. And what the province has laid out is a reopening plan that comes in three different steps. It is premised on vaccination uptake within the population and as well, some disease indicators -- how many people are in hospital? Or what proportion of people are in hospital? What does the reproductive number look like? These are the kinds of things that they're looking at. They've got this plan in place. I think that there was a lot of support around it, given that it was premised on evidence. And our sincere hope at this point in time is that let's move forward. Let's do the best we can to keep disease rates down as much as possible. Let's all get vaccinated as soon as we possibly can. And then my sense is that we'll start to get back to life that looks more like it was before there was a COVID-19. And that's going to include such things as outdoor dining.

CP24: The numbers have declined below 1,000, the weather is beautiful, and people are vaccinated. Can we reopen faster?

De Villa: I think it is a question of looking at the numbers. And I would just remind people that we've gotten a little less sensitive to numbers like 1,000 but hundreds of cases a day is still a pretty significant number. I would suggest to us that let's continue to really push to drive that transmission down. Let's keep getting vaccinated. And then soon, right, we will be getting to that point where we can start to resume some of these activities, starting off with lower-risk ones like outdoor activities first. And as things get better and better, starting to move towards activities that are increasingly indoors.

CP24: A viewer asks, what recommended benchmark will be used to determine when it is safe to no longer wear our masks indoors?

De Villa: I'm not sure that we've quite landed on all of those markers yet but know that there are lots of tables discussing. What's the best available science? What does the evidence tell us? And, of course, it's a constantly changing set of circumstances. We talked a little bit earlier in one of my earlier answers to a question about new and emerging variants, the B.1.617or the Delta variant and other variants that may come along because there is still a COVID-19 transmitting around the world keeps us on our toes. And so, we're constantly having to evaluate and re-evaluate the different actions despite vaccination. But please keep in mind that vaccination continues to be one of the key mainstays for all of us in terms of protecting ourselves and protecting those around us. And in the meantime, I would just ask that people continue with keeping distance and wearing masks when distance can't be maintained. And, of course, taking advantage of the nice weather and the outdoor space where risk is definitely lower.

CP24: What are your final thoughts this week?

De Villa: I had the opportunity to address the press earlier this afternoon and just reminded everybody to absolutely get vaccinated as soon as you can. There are lots of channels available. It's the best thing we can do right now. But in the meantime, I would ask people to keep their distance, wear their mask, do what they can to keep ventilation really good when you're indoors and if you're in the company of others from outside of your household, do that outside as much as you possibly can. I think if we do all these things together, we'll get to the other side of this sooner rather than later.