SASKATOON -- Canada saw a 66 per cent spike in cases of the Delta coronavirus variant last week with more than 2,000 confirmed cases nationwide, of which 105 are in Saskatchewan. CTV News Saskatoon reporter Jonathan Charlton spoke with Dr. Alexander Wong, an infectious disease specialist in Regina, to learn about what makes the Delta variant different from the original strain - and why vaccines are still so important. This interview has been edited for length and clarity.

What is the Delta variant and why is it different than other coronavirus strains?

There are ongoing mutations that occur as a result of viral replication. And some mutations, particularly in this spike protein, confer advantages to the virus in terms of, for example, infectivity or transmissibility, is what we call it. In other words, it makes the virus more contagious and more easy to pass from one person to another.

Then there are also mutations that can confer advantages in terms of the virus being more aggressive or more virulent, so that when you get it, you're more likely to get sick. ... The Alpha variant was more of what we call virulent, caused more severe illness and disease compared to the original wild type strain that we were seeing in the first number of months of 2020.

Now we have this Delta which is more transmissible. As a result of the different changes and mutations in spike protein, it's about 40 to 60 per cent more transmissible than the Alpha variant. The jury at this point is still out as to whether or not it causes more severe illness, more aggressive clinical courses compared to Alpha variant, but that doesn't necessarily appear to be the case yet.

Does the Delta variant make vaccines less effective?

The vaccines are less effective against Delta variants in terms of keeping you from actually getting infected with the virus and that's because the virus is more transmissible and it's easier to get. ... The numbers that are coming from the U.K. are about 30 per cent efficacy with a first dose against getting infected and then about then that increases typically by about 20, 25 per cent for the second dose of vaccine after you're 14 days out.

The key thing with vaccines, you know, 30 to 50 per cent doesn't sound very good, right, because the virus is more transmissible. However, the key thing with vaccines that's preserved is the fact that, with first and second doses it appears as though the vaccines are continuing to maintain very high efficacy in terms of preventing people from getting severely ill, or needing to go to the hospital or dying.

So again, this is the fundamental difference, and the reason why vaccines are critically important. If you're not vaccinated at all, you're much more at risk to have a severe course of illness where you might end up in hospital or ICU or die. And again, especially if you've been fully vaccinated, but even with one dose of vaccine, regardless of whether it's AstraZeneca, or one of the mRNA, vaccines, your risk having a severe course of illness is dramatically reduced.

I mean, that's anywhere from 70 to 90 per cent reduced if you had a first dose of either AstraZeneca or an mRNA vaccine. And then once you've had two doses of vaccine, that number goes to about 92 to 96 per cent. So it pretty much protects you almost completely against getting severely ill and needing to go to hospital. It's the difference pretty much between getting really sick and having to go to hospital, maybe ICU, versus just being at home and having what feels like a bad cold.

Does the emergence of the Delta variant put the end of the COVID-19 pandemic any further out of reach than before?

I don't like to use the term "end of pandemic" because the pandemic doesn't end when people say it does. The reality is that we still have lots of circulating virus in the province. The reality of what we're trying to get to in terms of the end goal is to be able to manage the pandemic, hopefully with minimal impact on our hospital systems. For me personally, ideally, we want to minimize the number of people who die as a result of getting COVID-19.

What Delta is going to do is, Delta is probably going to find the pockets of individuals everywhere, not just in this province, but everywhere who are not vaccinated. Those individuals are definitely going to be at very high risk of getting infected. Now, again, we know that the majority of people in the province, pretty much in the country, who aren't vaccinated tend towards the younger crowd at this point. Younger people, again, are less likely to get sick as a result of COVID. But the reality is, is some of them are going to get sick, some others may up in hospital, and a small number of them are going to die, right?

And so, you know, this is why we're really pushing vaccine as hard as possible, because we want to minimize the number of people who get sick and who die. Pushing first and second doses as hard as possible in lots of different ways is going to be our ticket to getting to a point where we're going to be safe in terms of not having our hospitals system overrun, etc. And I do think we'll get there. But it's not like the pandemic is ever going to quote-unquote, end, right? People will feel as though things are going back to normal to some degree, but there will always be circulating virus and it'll just be something that we learn to live with.