Front Burner - Your 4th dose questions answered

Episode Date: July 21, 2022

Canada's latest COVID-19 surge is being fuelled by the BA.5 variant. It's prompting some public health officials to make fourth jabs of a COVID-19 vaccine available to all adults. While most provinces are already offering fourth doses to their most vulnerable residents, some — such as New Brunswick, Quebec and P.E.I. — are urging the general adult population to sign up as well. However experts are divided about the urgency at which Canadians should receive a second boost, and when. Prof. Raywat Deonandan is an epidemiologist specializing in global health at the University of Ottawa. He breaks down what we need to know about the future of COVID-19 vaccination.

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, like me, probably have a lot of questions right now about whether you should get your fourth COVID shot or not. People over the age of 18 in most provinces are eligible.

But the messaging around whether or not everyone should get it is, well, pretty confusing. With some experts saying go for it, do it, and others suggesting that depending what group you fall into, you may want to wait until the fall when a new Omicron targeted vaccine is expected. So we want to talk about that today, but you might also have other vaccine-related questions, like should your toddler get this new Moderna shot for under fives? Where are we with a universal coronavirus vaccine? And what the heck is Novavax? We got you.

Friend of the pod, Rewa Dianandan, is here to wade through all of this. He's an epidemiologist with the University of Ottawa. Hey, Rawat, how are you? I'm doing well. How are you? Good. It's great to have you. Thank you for making the time. So look, a big part of why people are holding out on the fourth dose is because they're waiting for this new bivalent vaccine that's supposed to be released in the fall. I hope that I pronounced that right. So before we even get into talking about the fourth dose, I wonder if you could explain to me what this new shot is. Like what is a bivalent vaccine? Well, it's bivalent as opposed to monovalent or multivalent. Bivalent. Okay. So I did not pronounce it right.

All it means is that there are two viruses targeted in the formulation, as opposed to the original version of the vaccine, which targeted just one virus, which is the original Wuhan strain that was terrorizing the world in the beginning of 2020. Drastic measures to halt the spread of that deadly virus. Wuhan, China, ground zero for the outbreak, now under lockdown. So five provinces are under states of emergency tonight. Ontario, Alberta, and BC, PEI, and Quebec. The U.S. is now reporting more COVID-19 deaths than anywhere else in the world.

More than 20,000 people there have died. We have multivalent vaccines with us all the time. It's like the flu vaccine is multivalent. It targets a variety of flu strains in a single shot. This new bivalent COVID dose is attuned to both the original Wuhan version and to the BA1 version of Omicron. So the assumption is that it will be more effective against prevention of infection and serious outcomes of Omicron and its lineage. Even if we're dealing with the BA4 and the BA5 variants of Omicron right now? That's a good question. And right now, as you know, more than 80% of cases in North America are probably due to BA4 or BA5. And as we speak, it's probably even higher than that.

There have been some laboratory studies. What they've done is expose the tissue, the blood of people vaccinated with the bivalent vaccine as their fourth dose, expose that to BA4 and BA5. And they found that it does elicit the production of neutralizing antibodies, I think fivefold more so than before the shot. So that suggests that it is effective, at least eliciting a response against BA5. But the devil's in the details. And here's the shot. So that suggests that it is effective, at least eliciting a response against BA5. But the devil's in the details. And here's the thing. They didn't really compare it to the amount of antibodies that would be produced if you were to expose the blood of people who got the regular fourth dose, the non-bivalent one, to BA5. So maybe it doesn't offer an advantage over a fourth dose with the existing vaccine, but

maybe it does. The data currently available does not answer that question. Why didn't they do that? Why didn't they test that? Yeah, maybe they have, maybe they will, maybe they won't. I don't know. It definitely works to some extent. The question is, does it work better than the existing version?

That we don't know. Okay. So given all of that, there has been some suggestion, including from some really reputable experts, that maybe it would be better for young, healthy people to wait for the bivalent vaccine rather than get the fourth dose of like the OG vaccine, your Pfizer, your Moderna. For the general healthy individual, a healthy 19 year old, at this point if they've had their two dose initial primer and a first booster, we know your level of protection is going to be very good in the next several months and I would advise that it's not absolutely

necessary at this point and that you can wait for the fall booster dose at that point. They do show in individuals as their fourth dose having antibody levels that are much higher than the original COVID vaccine. And so, you know, there may be some benefit here waiting to see what, you know, again, comes down the pipeline in terms of what this vaccine could do. It may not. What would you do? What are your thoughts on that? I don't think it's worthwhile waiting. And here's my rationale. One is that we're in the middle of a wave right now. So you want optimal protection now or close to now as possible. Two is when will this new bivalent vaccine arrive? It's supposed to come sometime in the fall. I don't know if the governments where you live have ordered sufficient volume for you to acquire it. I don't

know if you will be prioritized in line to get it. It may be that by the time your demographic comes up it's December or January, in which case you have sufficient waned immunity that you wish you'd had a fourth dose earlier. And lastly of course is, as I mentioned, we don't know if it's actually better than the current fourth dose in preventing BA4 and BA5. And by the time fall rolls around, maybe a different variant will be terrorizing us, in which case maybe any advantage garnered

by this new bivilliant formulation will be minimal, if any. So I think all signs point to getting it now rather than later, even if the advantages are small. Right, because by the fall, we could be dealing with an entirely different variant here, like some new gamma variant that nobody's even thought about yet, right? That's right. Now, let's back up for a second. And scientists categorize these variants in three categories, variants of interest, variants of concern, and variants of high consequence.

We have never seen a variant of high consequence for COVID yet. We've seen lots of variants of high consequence. We have never seen a variant of high consequence for COVID yet. We've seen lots of variants of interest and the famous variants of concern that we're all aware of like Omicron and Delta and so forth. And they're categorized that way because of the virus's ability to compromise our ability to detect, prevent, and treat the disease. Now, because we haven't seen a variant of high consequence, it's unlikely we're going to see one of those coming up soon. It is likely, however, we'll see another variant of concern. Now, I make that distinction because even if a new gamma variant arises, the current vaccines will probably still be somewhat effective against it. The new variant probably won't be escaping the effects of

vaccination altogether. One thing I wanted to ask you about was this study out of Israel, and it suggested that a fourth dose is great for people 60 and up or people who are immunocompromised, but maybe not so much for younger, healthy people. And I just wonder if you could tell me about that data and maybe what you would say to a younger, healthier person that's like, well, why bother getting this fourth dose? So if we're talking about the same study, this one looked at about a thousand, a thousand and fifty healthy-ish, youngish healthcare workers in Israel, as you noted, and 300 or so of those got a fourth dose. And they compared the antibody responses of those people to the age-matched controls in the same cohort.

What they found was that a couple of weeks after the fourth dose, their antibody levels were a little higher than they were five months after the third dose, suggesting that this fourth dose does offer some advantage, but it wasn't a huge advantage in terms of antibody production. So any sort of ability to prevent infection is probably moderate. However, this is a laboratory study, and oftentimes these laboratory studies don't translate into real-world data. They try to estimate a vaccine efficacy score out of this data by hand-waving a little bit and suggested that maybe it offers a 30% advantage in preventing infection. The sample size is way too small to make that kind of conclusion. So what I take away from that study is it's suggestive, but it's a

small study, and there's not a lot you can take away from it, frankly. What we need is to repeat the study. And at the bottom line, it does offer some advantage, just not a huge advantage, according to this small study. So I take your point that the evidence shows it offers some advantage. Ontario's chief medical officer of health, Kieran Moore, recently said that he's not recommending the fourth dose to everyone in part because the COVID vaccine could have a small risk of myocarditis.

For an 18-year-old healthy individual, the risk of getting hospitalized if we have no underlying medical illness is very, very low. We know there is a risk, a very small risk, one in 5,000 that may get myocarditis, for example. And you'd have to have that discussion on the risk benefit of a complication from the vaccine versus a benefit of decreased hospitalization. I know some doctors are taking issues with what he said. And I wonder if you could explain the debate for me here, because I wonder if you're somebody kind of weighing this fourth dose, maybe you're like, well, perhaps it gives me a little bit of benefit, but I also have this risk of myocarditis. So I don't know what to do.

Yeah, we're in a strange time in history where we have to make these somewhat life or death decisions based upon math. So Dr. Moore suggested that the risk is one in 5,000 of causing myocarditis, which is just wrong. That's outright wrong. Public Health Ontario data of 12 million or more vaccinated people in Ontario suggests that the risk is more like 1 in 30,000 to 1 in 60,000. It's quite remote. And on top of that, if you do end up

being an unlucky person to get myocarditis, the majority of those cases will resolve by themselves, but any need for medical intervention, and the ones that do require medical intervention resolve in a few weeks. And there have been no known deaths in Ontario as a result of myocarditis caused by COVID vaccination. The important thing to think about here is that the risk of getting myocarditis, if you're a young man, from COVID itself is about six times greater than getting it from the vaccine. So you have to ask yourself, what are my chances of getting COVID? If we'd had this conversation a year ago, I would say, well, it's probably not as great because of being vaccinated, but COVID is everywhere now and your chances of getting it are actually quite high.

So I would argue that because your risk of getting myocarditis from COVID is high, and your risk of getting COVID is high, and your risk of getting myocarditis from the vaccine is lower, I think the calculus bends in favor of getting vaccinated. 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. through angel investment and industry connections. 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.

maybe have already even had COVID and are just feeling really apathetic right now about this entire conversation. Like frankly, maybe they did not even want to click on this episode that we're doing. And they're just feeling like however many shots they get, it's not enough that they're going to get COVID anyways. And this has deterred them even from getting their third shot, not even to mention the fourth one. We have to take a step back and ask ourselves, what is the point of COVID vaccination, this formulation of COVID vaccination? It's not to prevent getting infected. That would be nice. That's not what the trials tell us about. The trials tell us the ability to prevent symptomatic disease, and on top of that, the ability to prevent hospitalization and death. The vaccines are extraordinarily good at preventing hospitalization and death, which is why we're able to have an open society now, as opposed to, say, May of 2020, when everything

was closed down. So we've taken the fear of COVID out of the equation because the fear of death has been downgraded, not to zero, but downgraded. So if you want to continue not being afraid of death, continue to seek upgrading your vaccination is not a bad thing to do. On top of that, there is some troubling data suggesting that with every reinfection, we increase your chances of hospitalization and death, as opposed to other diseases in which reinfection actually increases your immune profile. This disease may decrease it. It's unclear, but that is what some data suggests. If that's the case, I think it's worth erring on the side of doing whatever you can to prevent infection until we get a better

vaccine that will prevent infection for us. So that means getting boosted. What about long COVID? Would getting these additional shots help your chances at avoiding long COVID? I don't know. In fact, no one knows for sure. We know that vaccination overall seems to reduce the risk if you compute this at a population level, not to zero, but overall it does reduce the risk. It's unknown whether repeated vaccination reduces the risk further. It probably does, to be honest, if it means you avoid infection. So getting boosted reduces your chance of infection, not to zero, but somewhat. And that means your chances of getting COVID comes down as well. Okay. All right.

So summary, go get your fourth shot, no matter who you are. That is my opinion. Now, because there's no downside, really. There's a tiny risk of myocarditis. And if you're in that demographic, I understand your hesitation. But for everybody else, the risk is minuscule, whereas the potential benefit is quite extraordinary. Okay. And I know that children under 18, I don't think they're being approved yet for the fourth dose, but same advice here? Same advice? Well, it's unclear what the advantage would be for kids under 18. Have to look at the data more intensely.

But if you are eligible for a third dose, that's the kicker here. The advantage garnered by a third dose is really quite immense. The advantage garnered by a fourth dose is what people are debating. But the third dose, there's no question. So I'm hoping that enough data comes forth to be convincing about a third dose eligibility for people under 18, because I think that might be a bit of a bit of a game changer. Okay. And now I want to talk to you about kids under five, little kids. So the Moderna vaccine was recently approved by Health Canada for under fives, which means that approximately 1.7 million children in Canada are now eligible to be vaccinated. I can imagine that some parents might be hesitant.

This is still a super new vaccine. You have a toddler who I know is almost the exact same age as my son. And on a personal note, how are you making this decision and what kind of conversations have you, if you don't mind me asking, have you and your wife been having about this? My spouse is a family doctor, so we have this conversation at a fairly scientific level, and we agree it is the right thing to get him vaccinated. The risk, we agree, is minuscule because the clinical trial data shows that the risk is minuscule. So the trial data on, I think, 11,000 or so kids that Moderna had enrolled shows that the antibody production was akin to what you see in adults. And doing some

magical statistical hand-waving, something called immunobridging, they conclude that the ability of vaccination to prevent symptomatic disease is about 51% for kids under two and about 37% for kids between two and five. That doesn't sound like a high number, but it's pretty high when you consider that it probably means the ability to prevent hospitalization and death is very, very high. So what we care about as parents is keeping my kid out of the hospital and out of something more serious than that. It would be great if I can prevent my kid from suffering at all.

So no symptoms. And again, 51% or so is what I'm getting for that. But I'll take what I can get. The kinds of risks that the Moderna clinical trial showed was the stuff that kids get with vaccination in general, pain at the injection site, some swelling and redness. Probably the worst thing is the fever that kids got. And that was pretty common, but that was resolved within a few days. So the worst thing your kid is risking is probably a fever. I say probably because we don't know what will happen when this is rolled out to millions of kids. Some of the rare adverse events will probably pop up. But remember, millions of kids

between the ages of 5 and 18 have gotten this already, and nothing extraordinary has been seen yet in terms of adverse events. What might these rare adverse events be? Oh, I don't want to scare people. But, you know, with the flu vaccine, we have Guillain-Barre syndrome, and maybe some myocarditis even that we observe. Who knows? Who knows? But nothing extraordinary has been observed. Even with this new variant, with the

new variants, is there still evidence that the Moderna vaccine will work against the BA4, BA5 for these little kids? So your immune system has two arms, the humeral arm and the cellular arm. The humeral arm is the antibodies. That's what keeps the invaders out of your body to begin with. The cellular arm is the T cells and the B cells and fun stuff like that, that prevents the infection once it happens from being serious. What the vaccines are showing is that the cellular immunity is quite robust. Even though the ability to prevent infection as a whole is diminishing week to week, the ability to prevent serious outcomes is maintained regardless of the variant. That's what I meant earlier about separating out the variants of concern from variants of high consequence. So long as a variant of high consequence doesn't

arrive, I'm pretty confident that the vaccines will do a good job at preventing the worst outcomes for most people. The last thing I wanted to talk to you about today is what you mentioned earlier, this universal coronavirus vaccine. Pfizer just started trials. So, you know, my understanding is it's not just for SARS-CoV-2, right, but other coronaviruses too. And so what do we know about this so far? Well, not a lot. So the holy grail is the pan-coronavirus vaccine, as they call it. And this would be good for pretty much all coronaviruses, SARS, MERS, any variant coming down the pipeline. So you're one and done essentially, or one series and done hopefully. Now the Chinese and the Cubans claim to have one called Pan-Corona, but I've seen no data about it, so who knows what that's all

about. And I'm glad to see that companies like Pfizer are on that road. But it's way early to know if this is a viable scientific path to take. I hope it is. And I think this eventually will be the thing that we hang our hats on for a variety of future pandemics involving coronaviruses. So essentially what you're saying is like this is like the measles vaccine and that it just eradicates coronaviruses? Or do we think about it more like a highly effective flu vaccine? A highly effective flu vaccine, I would think of it that way, that doesn't require necessarily a boost every year. We probably can't eradicate COVID for a number of reasons, including the fact that it does

rest in animal reservoirs, so animals can get it. So if we can eliminate it in humans, it's still going to exist in the animal population and ping-pong back and forth with us. So we should get eradication probably out of our lexicon at this point. But getting it under serious control, we don't have to think about it anymore. I think that is within the realm of possibility with current biotechnology. Oh my God, that would feel so good.

Ray Watt, thank you. Thank you as always. It is my pleasure. All right, that is all for today. I'm Jamie Poisson. Thanks so much for listening. Talk to you tomorrow.