Front Burner - COVID's latest subvariants: What you need to know

Episode Date: June 30, 2022

The Omicron subvariants BA.4 and BA.5 are spreading quickly. They already make up a majority of new COVID infections in the U.S., and it appears they are much better at getting around immunity. Research from Harvard Medical School shows the BA.5 subvariant “may escape antibody responses. The spread of these subvariants has coincided with the lifting of mask mandates and the relaxing of many public health measures nationwide. To provide you with details about the latest COVID-19 variants and the state of the pandemic here in Canada heading into the summer, we are joined once again by Dr. Zain Chagla, an infectious diseases physician at St. Joseph's Healthcare in Hamilton.

In the Dragon's Den, a simple pitch can lead to a life-changing connection. Watch new episodes of Dragon's Den free on CBC Gem. Brought to you in part by National Angel Capital Organization, empowering Canada's entrepreneurs through angel investment and industry connections. This is a CBC Podcast. Hey, I'm Jamie Poisson. So you're not going to like this, but... Calls for a fourth vaccine are growing louder as a new sub-variant of Omicron is fast becoming the dominant strain of COVID-19 in Ontario. The Omicron sub-variants of BA4 and BA5, they're spreading

pretty fast. They already make up a majority of new COVID infections in the United States. And it appears that these variants aren't too concerned with your immunity. Research from Harvard Medical School shows the BA5 may escape antibody responses among those who've been infected with COVID-19 before and those who've been infected with COVID-19 before and those who've been fully vaccinated. The spread of these variants, as you probably noticed, coincides with the lifting of mask mandates nationwide and the return of quote-unquote normal life.

So today we want to give you the details on the latest variants of COVID-19 and what the state of the pandemic is here in Canada heading into the summer. We're lucky to be joined once again by Dr. Zane Chagla. He's an infectious diseases physician at St. Joseph's Healthcare in Hamilton. Hey Zane, thank you so much for coming back on the show. Oh, thanks for having me. Okay, so we have now gone through a whole bunch of COVID sub-variants. And I feel like a lot of people are kind of tuning out. But these ones seem to be cause for some concern here. So I wonder if we could

start here. What are these new sub-variants BA4 and BA5? Yeah, so these, you know, derive from the original Omicron family. And so these were probably described around the same time Omicron started emerging in December 2021. But they carry mutations that are very different than the first two Omicron variants that we dealt with. So BA1, which was the one we dealt with when Omicron first came, and BA2 kind of through March and April, that caused a bit of a second resurgence in different places around the country. These have more mutations. Some of them are a little bit more immune evasive. And, you know, I think we are seeing through some antibody studies that we're looking at is that they are very different in terms of how our immune system reacts in,

you know, in keeping both with how it reacts in people that are vaccinated or people that had prior infections, including with BA1, where antibody levels are much, much lower for BA4 and BA5, really suggesting that reinfections could occur in individuals that already had COVID in the last few months. Okay, so if you can get reinfected if you had COVID, what about if you're vaccinated? Is that helpful at all? Yeah, absolutely. So, you know, the vaccines, at least, you know, data that's come out of real time in places like South Africa showing that

vaccines significantly reduce hospitalization. And even in the wave that's occurred in Portugal, similarly, the hospitalizations are still overrepresented by people that are less optimally vaccinated. Obviously, you know, in the context of Omicron, we talk about vaccines and including vaccines in a booster. But, you know, certainly there may be less of that protection against infection. We all knew with Omicron, BA1 and BA2, over time, the time after getting an immunization, your protection against infection dropped over time. It's likely that with BA4 and BA5 that, you know, again, that protection against infection is actually even less than what we had with BA2 and BA1. And recognizing that, you know, the vast majority of the population who got boosted got boosted in December,

January, and February. It's already been six months since then when, you know, even with BA1, BA2, their protection against infection had also declined. Yeah, so that's me. That's me. I got boosted in December. So, like, does that mean that this is not helpful anymore, this vaccine that I got? No, 100 percent, there's still benefit, right? You know, again, in Portugal and South Africa, there is good data to suggest that people who ended up in hospital were less than optimally vaccinated, most commonly unvaccinated, but with one or two vaccines in that sense. So there is absolutely a reason to be fully vaccinated going into this

for protecting people against severe disease, and fully vaccinated for most populations includes a third dose. But yeah, if you were exposed to COVID, is your vaccine going to hold up in terms of protecting you against infection? That may be much less than it has been before. And, you know, that is part of the recognition that, you know, some people may get infected here that have not been infected at all during the pandemic and have had, you know, a full series of vaccines. Should we be going for like a fourth dose here? I've also heard people talk about like an Omicron specific booster, which basically I think is like a mix of vaccines. Yeah, so let's talk about kind of using the original vaccine as the next dose. And, you know, we had data from Israel from

the Omicron waves, the beginning of Omicron, where they gave fourth doses to people. the Omicron waves, the beginning of Omicron, where they gave fourth doses to people. And they really saw that in older individuals, so those over the age of 60, that they did derive benefit, that there was a significant reduction in severe complications of COVID-19. But we're talking, you know, in the order of a couple of hundred severe or fatal cases compared to, you know, 100 severe cases. So, you know, there was a big benefit, there or fatal cases compared to, you know, a hundred severe cases. So, you know, there was a big benefit. There was 50 to 60 to 70 percent benefit. But absolutely, you know, the people with three doses still had significant protection against severe diseases. Fourth was better. But when you look closely at those individuals and you

follow them over six months, their protection against infection does drop. And in that same cohort, you know, the 60-year-olds, when they followed them eight weeks after their vaccine, they really were the same as three-dose vaccinated people in terms of protection against infection. So we do know that probably giving that fourth dose of vaccine in high-risk populations will reduce their risk of severity. In a population that's at very low risk of severity, that's had three doses of vaccines, you're probably not getting that much incremental benefit by getting a fourth dose. And again, you know, we have to recognize the original vaccines probably won't do anything in terms of impacting spread through the community in that context. And so really, it's an individual

piece based on your risk of severe disease. And what about this, like new special Omicron vaccine? Yeah, so the companies have been working on vaccines, Moderna and Pfizer have been working on vaccines, really combining the mRNA sequence of the original coronavirus, and then using BA1 or an Omicron-specific mRNA sequence to generate antibodies that may be better against Omicron variants. And so there were positive trials that were both released by press release from Moderna and Pfizer in terms of boosting antibody levels, you know, nine to ten times higher than the original booster of vaccine. levels nine to 10 times higher than the original booster of vaccine, so four doses of the original vaccine versus three plus the booster in populations. Some of that has been lost in some of the newer press releases for the BA4, BA5. They did do a good job boosting people nine to 10 times higher than what would be with the original vaccines in terms of antibodies.

When you look at BA4, BA5, you know, that got slashed a third, basically, in the context of these more immunovasive variants. So, you know, they probably will be a benefit, they probably will be important for especially for some vulnerable populations who we see overrepresented in healthcare. Are they going to be the magic bullet moving us forward through this pandemic to kind of get omicron under control and live like we did you know with very well-matched vaccines a year ago probably not and then really it is you know newer newer vaccine modalities that are probably going to be helping us through this rather than you know specific mrna vaccines in that sense. Why are these new variants so good at kind of skirting around immunity, right? Like they're reinfecting

people who have had COVID, you know, you just talked about vaccines or breaking through vaccines, like what is it about them? Yeah, I mean, I think you have to look at the global situation, right? So at the beginning of this in 2020, no one had immunity to this virus. And so every host was a susceptible host. And really, you know, the virus didn't really have to do much to get from host to host to host, which is exactly what the virus wants to do. It just wants to spread, right? As, you know, 2021 and 2022 go by, more of the population has been immunized, more of the population has had COVID. And so we now have the barrier for spread being much higher, that like, you know, a good chunk of the population is antibodies that could protect them against getting infected. incredibly transmissible to the bounds of what we think are even possible through transmissibility for a pathogen, or it has to evade immunity. And this is the path I think we're going to see

moving forward is that with more immunity means these viruses will have to evade immunity a bit more. This isn't unheard of. We see this with other coronaviruses that the kind of ones that cause the common cold is that there's a constant evolution that, you know, deals with the population's immunity and continues with virus kind of spread through it. But is it fair for me to say, I'm not even sure if I'm saying this correctly, but that maybe they're getting a little bit better at spreading, but the severity of them is less, right? Because people have those antibodies and are they just less severe? I don't know, for some reason, because they've mutated so much? No, I mean, it's a good question.

And there is certainly a genetic amount of fitness. There's only so many genes that can change with these viruses that, you know, there is some opportunity cost. I will say, though, as the virus evolved, the ability to evade immunity and the ability to cause severe symptoms from a virus standpoint, just native to the virus itself, were independent. We saw, you know, Delta being actually fairly immune evasive, but also very severe. And we saw the devastation in India that came from it. As you had mentioned, though, one of the biggest factors in terms of where we are in terms of severity is the fact that there is immunity in the population. It may not be enough to protect people against getting infected. But, you know, our immunity is still there to prevent severe disease, our T cell immunity,

our B cell immunity, our ability to know that this, you know, our body recognizes what COVID is when we get it in the sense that we're already primed, our immune system knows what's going on. It may be not enough to keep us from getting a runny nose, a sore throat, etc. But it is enough to keep the vast majority of us from landing in the ICU. And so, you know, as this virus evolves continuously, you know, that immunity in the population is still there, and it's going to be there for some time. And so it may appear that the virus, even though it could be in a native population, much more severe, much more mild over time in a more immune population, because of the fact that

everyone's immune systems are primed to this. So in that context, maybe you're going to hate me for asking this question, but on a scale of one to 10, I guess, how concerned are you about these sub variants right now? If 10 was like OG COVID, you know, like really, really alarmed times. Yeah, I mean, I think OG COVID was 10, you know, for sure. There was a susceptible population. We didn't know what it was. We know there were horrific images coming out with the world. When Omicron came, I think we were at like six or seven.

We had more immunity. People had been immunized, but we recognized this could spread fast and that the vaccines would probably not prevent a significant amount of transmission. I think we're sitting at about three, four here. Right. So I think we've been in a lull. Things have been great. But there is the potential for more cases. You know, we recognize there are populations that are still overrepresented in terms of hospitalization. Those who live in congregate care facilities, those who are extremes of age, particularly elderly, those who have immunodeficiencies and may not make a good immune response, even to be vaccinated, even to being infected.

I think that this does create a bit of risk in those groups again. And again, that part is challenging as well as I think we're all not immune to seeing what's happening to our medical system, that even incremental small pressures on the medical system that is already stressed to the hilt is going to be difficult to deal with from a health care provider standpoint. And I think even if the vast majority of the population does find, you know, that any incremental hit to the medical system is going to ripple down through patient care moving forward. Given that I've seen calls from doctors across the country that they feel like we got to bring some restrictions back, people are no longer wearing masks in most public places. But with what we know about variants, they're saying like, we should go back to some of those. And how do you how do you feel about that? Like, you know, putting your being required to put your mask on to go to the grocery store right now? I live in Toronto, it feels like it's

about 5050. Generally, this is this is a contentious issue. And I will say, look, you know, when we were facing other waves, you know, we didn't have as immunized population, we didn't have treatments, which, you know, are now freely available and are prescribable through primary care in most of the country. So even some of those high risk patients have another layer of security to make sure that they're not getting sick with COVID. You know, when we talked about public health rules, they made sense in 2020. I completely understand all we could do is control spread of the virus to try to control our healthcare utilization. These trickle down effects aren't necessarily as potent now. Masking may help, but, you know, on a community level, is masking going to change the trajectory

of what's coming with BA4 and BA5? Maybe to a small degree, but it's not necessarily going to change the trajectory of what's coming with BA4 and BA5? Maybe to a small degree, but it's not necessarily going to be a huge impact, right? And I think we also have to think about this on a roundtable of what it means for population compliance, pushing people from public health measures, what happens, you know, in public buy-in, if there's a new vaccine to get people in, etc. You know, I think we have to really have realistic discussions of what's going to happen here. And I remind people, right, BA4, BA5 is here. It is taking over.

It is going to be the most, you know, fit variant that's out there. It's not going away if we mask, right? The second that we open things up, unrestrict things, et cetera, it will be waiting there or whatever is more fit than that, right? So, you know, again, there are lots of things we can focus on in terms of making sure people have optimal access to vaccines, that those who have only gotten two have come back for their third, that elderly have gotten their fourth doses, and those who are immunocompromised, that treatments are there, that preventative therapies like Evusheld, which we're using in

our transplant patients are there. Those are things I think we can double down on in terms of really making sure the medical system impact is minimized and, you know, leaving people to make their own risk judgments in terms of how much risk they want to have as this spreads through our society. In the Dragon's Den, a simple pitch can lead to a life-changing connection. Watch new episodes of Dragon's Den free on CBC Gem. Brought to you in part by National Angel Capital Organization. Empowering Canada's entrepreneurs through angel investment and industry connections. Hi, it's Ramit Sethi here. You may have seen my money show on Netflix. I've been talking about money for 20 years. I've talked to millions of people and I have some

startling numbers to share with you. Did you know that of the people I speak to, 50% of them do not know their own household income? That's not a typo. 50%. That's because money is confusing. In my new book and podcast, Money for Couples, I help you and your partner create a financial vision together. To listen to this podcast, just search for Money for Couples. In the U.S., vaccines are being made available for children under five, and I know they're expected to do that in Canada, I think, fairly soon, right? And so do you think that will move the needle at all as well? I say this in part because I have a two-year-old, and it just feels like every week someone

has COVID in that center. Yeah, look, again, you know, by the time we have a Pfizer series, that's three doses, even the Moderna series is two doses and, you know, potentially a booster. Is it going to, you know, help mitigate hospitalizations in younger individuals? Potentially, and people should be supported if they want to consider it, if it's considered a safe vaccine by Health Canada.

Again, you know, the vaccines are probably not going to necessarily change transmission dynamics in the community, right? And I think we have to really, really, you know, put that front and center that, you know, we are probably not going to be able to stop waves with vaccines anymore. We were able to in Alpha and Delta. But, you know, again, vaccination is going to be a choice to help with protection against severe disease. And it needs to be taken into context, especially with these populations, you know, amongst them about, you know, making sure that people understand the vaccines, that we support parents and that we have strategies for parents, especially as many of these children have had COVID as well. And, you know, what's the optimal strategy for vaccines for those individuals in that sense? So, you know, again, it's going to be great that we have them. And I think it's going to be a nice tool to have available that we have all of our populations that are able to be vaccinated.

But at the same time, it's probably not going to prevent, you know, the wave from occurring in any large form. Okay. So final question. As you mentioned, we probably can't prevent these future waves from occurring. And if this way, BA4, BA5 is like a 3-4, I guess what I'd like to ask you about before we go is, do you have concerns that something

like a lot worse could come along? And I think I think that's what a lot of people are maybe quite concerned about, right? That something COVID related is going to catapult us back to, you know, those early NBA shutdown days, right? Yeah, I mean, that Rudy Gobert game still gives me PTSD. I remember very well. You know, I will say, look, that the difference, and I think I've mentioned this before, is that there is a lot more immunity in the population, right? There is a very big difference from March of 2020 to now is that a lot of the population has antibodies to COVID-19 one way or another. Yes, there may be a more immune evasive variant.

It's going to be very hard for a virus to evolve to essentially escape all features of our immune system. Our immune system has evolved over time for, you know, multiple pathogens to be able to deal with them. And so, you know, it is something to watch for, you know, again, this pandemic has been incredibly humbling in terms of what we can expect a virus to do. But at the same time, deaths are lowest in history in terms of this pandemic after the first wave. Immunity is really holding up to prevent those severe complications. And it is a huge barrier for the virus to change, to evolve past all of it and essentially become a new virus altogether at that sense. So, you know, I think we are, you know, cognizant that this virus is going to evolve as time goes on as it finds more pockets. But at the same time, I don't know if we can overcome

immunity and all of this. And again, that's that's going to be protective for this population to make sure that those health care strains that happened in wave one, two, and three aren't necessarily going to happen again. Okay. Zane, thank you. I don't want to say that this conversation was all good news, but we've had some really rough news on the show lately, and this wasn't like a complete downer. So thank you. No, no problem. No, no problems. All right, that is all for today. Just a heads up, we'll be taking the day off tomorrow, but we're going to be dropping a special episode from CBC Podcast. So please stay tuned.

I'm Jamie Poisson. See you on Monday.