‘Running out of luck’: An infectious-disease expert on variants and Ontario’s third wave

TVO.org speaks with McMaster University’s Zain Chagla about transmissibility, bad outcomes — and why we shouldn’t just blame the variants
By Matt Gurney - Published on Apr 09, 2021
Zain Chagla is a consultant physician at St. Joseph’s Hospital and Hamilton Health Sciences. (The Agenda)



Are COVID-19’s new forms truly game changers? Are they really new diseases? TVO.org took our questions about variants and the third wave to infectious-disease expert Zain Chagla, a consultant physician at St. Joseph’s Hospital and Hamilton Health Sciences and an assistant professor of medicine at McMaster University.

Matt Gurney: We’ve heard a lot of late that “the third wave is different” or that “it’s like a new disease.” So let me start with a completely hypothetical question: If the variants now loose in Canada had been our first experience of COVID-19, how would we understand it? What would COVID-19 mean if this had been our first contact with it?

Zain Chagla: That’s a really interesting question. The actual transmission of COVID-19 has not changed. But we are seeing now, thanks to the variants, what we worried we’d see in January, February, and March 2020. Then we didn’t know much about COVID-19, and we worried that it would attack large swaths of society, overwhelm the ICUs, and cause a lot of deaths. It didn’t happen like that. Though there were obviously fatalities and health-care systems struggled, for most people, we were surprised how well they did. This virus really, really fed on those that were older, had major comorbidities, and were in long-term care.

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Now, as we look at these variants, we are seeing increased transmissibility and potentially slightly more complications in younger individuals than we saw in the first waves. It is a little bit of déjà vu, because what our thoughts were when COVID-19 was getting started is what we are angling toward now. We are seeing some really big transmission events and younger populations being hit in ways we expected before but never really saw.

Gurney: I remember having some very grim conversations in January 2020 with friends and family when the information out of China suggested this thing would kill a few percentage points of any population it infected. I was doing math — if it infects half the population and kills 2 per cent of everyone it infects, what’s that going to mean for Toronto, for Ontario, for Canada? And then, once it really hit in North America, we began to see exactly what you’ve described. It was worse than that, for a fairly narrow group, the elderly, and the young largely shrugged it off. It was scarier for some and not particularly serious for others. That seems to be changing now, at least a bit. Should a young person be worried today in a way they didn’t have to be before?

Chagla: Well, take the B1.117 variant, the one linked back to England. The Ontario data to date suggests people are more likely to be hospitalized — 1.6 times more likely. They’re two times more likely to end up on a ventilator. And, again, 1.6 times more likely to die. But we have to keep these numbers in context. A 30-year-old’s baseline risk of death isn’t high, and a 1.6-times-higher number still isn’t very high. These are small numbers on small numbers.

But young people still have to be careful, because we are definitely seeing a pattern of younger people getting very sick, needing a hospital, ending up in an ICU, and then facing a long struggle. So: Worry? In proportion. Odds are, a young person, even with a variant, will be fine. But that’s not as certain as it was in March 2020. There is a higher risk of serious illness and, unfortunately, some may die ... more than in 2020.

Gurney: Speaking of outcomes, we’re hearing that the virus is more aggressive now, that it does more damage. Are even the survivors of this wave facing a tougher recovery?

Chagla: Some people come to hospital with COVID, and they need a stay of a few days. A younger person, especially, might be in for a day or two and then home to recover. What matters is when someone needs critical care. That’s a very big deal. If you’re in an ICU, and if you’re on a ventilator, if you survive, you don’t just go home and start running again as soon as your breathing improves. We’re seeing muscle wastage. We’re seeing nutritional difficulties. There are secondary infections. These are things that can happen with any ICU stay. These patients will need rehabilitation, and some may continue to need supplemental oxygen at home. In absolute terms, for younger patients, these numbers are still low. But, as I said, there are more now than before. This is a challenge for the patients but also for health-care systems that are struggling to meet demand. Patients with long recoveries still need a lot of help from systems under pressure.

Gurney: We’ve learned a new set of behaviours, a new way to live, since this began. Do we need to unlearn some of that and change our strategies to adapt to these variants?

Chagla: I think it’s better to say that we need to remain committed to what we’re supposed to be doing. The major changes with transmissibility for these variants are that people have very high levels of the virus, relative to before, so when they’re shedding virus, there’s just more of it.

These variants might also be more likely to stick to a respiratory tract; there is some data about that, suggesting they’re more likely to cause an infection after exposure. Prior to the variants, there were still a lot of cases where even very close contacts didn’t result in infections. Husbands and wives, even. One partner gets it, and there was only maybe a 20-30 per cent chance the other would. That told us that, even in a very close-contact situation, there were still natural factors blocking infections. Maybe the virus didn’t stick well. Maybe there wasn’t a lot of shedding, maybe via coughing, when there was a lot of virus. That type of thing. So even when everything went wrong, people weren’t getting infected — well, 30 per cent were, but there was an obvious buffer blocking infection for the rest.

That has really been reduced now. We are starting to see higher numbers of infections from those exposures. The conditions of exposure are the same, but the natural buffer that prevented infections even after a high-risk exposure is dropping. We are seeing high viral levels. We are seeing more virus sticking. And we are seeing more infections. This is still predominantly a close-contact disease transmitted by droplets and aerosols. It spreads in indoor settings, particularly poorly ventilated ones, where mask usage isn’t great. In workplaces with close proximity, in prisons and shelters, where people can’t separate and hygiene overall is poor, we aren’t getting lucky breaks like before. We are running out of luck and seeing more transmission than before.

Gurney: I want to do something annoying and make you sort of answer a bunch of that again in a slightly different way. If you were explaining to someone how “COVID Classic” and the variants in Ontario today are different, what differences would you highlight?

Chagla: More transmission in comparable environments and an overall worsening in outcomes are the big differences. Some of these variants seem to pose a reinfection risk — having experienced COVID last year doesn’t necessarily prevent infection from variants, though it might still provide some protection from serious illness. In Canada, this isn’t a huge issue, because we’re doing reasonably well at preventing infections. But in other countries, where it’s harder to prevent infections and where health-care and hygiene systems are more fragile, this is not good. These communities do not want to be dealing with large numbers of reinfections.

Gurney: This is sort of a meta-question, but given all that we’ve discussed, have the variants changed the game?

Chagla: That’s a good question. They are increasing transmission — no doubt about that. In the settings I just described, the variants are increasing transmission. But you know what? We can’t just blame the variants here. When we came out of the second wave, we still had a lot of transmission. We had a lot of people still in our ICUs. And we began lifting restrictions even though we knew there was a lot of transmission happening, especially in essential workplaces. Unfortunately, even without the variants, I think we would have seen the same outcome in terms of a third wave. It might not have moved as fast. It’s been moving quickly these last few weeks. But you could see the trajectory in late February.

And I really take issue with people saying this is just because of variants. We didn’t let the health-care system decompress before opening up. We didn’t wait for transmission to come down low enough before opening up. We didn’t address where we know transmission is happening before opening up. We will have bad outcomes, and we knew that would happen.

Gurney: We’ve talked a lot about the race between the variants and the vaccines. Right now, the variants are winning. What is going to happen over the next 30 to 60 days?

Chagla: We’ve now shut down the province. We’re seeing 3,000 cases a day — slightly more, now. [Editor’s note: that jumped to 4,200 the day after this interview was conducted.] Four or 5 per cent of those are going to need hospitalization; 1 or 2 per cent of a 3,000-plus daily cohort will need ICU care. So on a day with more than 3,000 cases, you’re going to see 30 to 60, call it 50, people that will need an ICU bed, and roughly double that that will need a hospital bed. Those are just round numbers, but every day with 3,000 patients, say 100 will go into hospital and half of those into ICU. But that’s going to happen 10 days down the line.

So the changes made this week, including the stay-at-home order, won’t begin to produce changes for probably up to 14 days. Maybe seven, maybe 10, but maybe as long as 14. Then the case curve will start changing. Unfortunately, hospitalizations are cumulative. People stay in hospital a long time. We’ll be adding 100 cases a day for two weeks. We will hit a peak eventually, and then hospitals will get more crowded for up to 14 days after that. We are going to have huge strain on the hospital system over the next month, and that’s all baked in already.

After the peak, cases will come down. Let’s say we get them down to 2,000 a day. That looks great compared to where we are today. But that’s still going to be dozens of patients needing hospital beds and ICU beds every day, added onto the overloaded system. We will get the cases down under 1,000 a day eventually, and then we’ll have to process the patients already in the system. We will keep vaccinating throughout this period. In a month, maybe six weeks, we will be just starting to see the benefits of the stay-at-home order in our ICUs, which are going to be in very rough shape these next few weeks. We will likely see scenarios of patients being treated in tents. We will certainly see patients being transferred farther and farther out of hot spots.

Gurney: How bad could it get in the hard-hit areas?

Chagla: Well, like I said, we’ll see some of the scenarios we’ve been planning for, particularly in the Toronto area. Large-scale patient transfers. Probably field hospitals. We’ll have to treat patients in very non-conventional environments. That’ll play out over the next four weeks, and people should be prepared for that.

Gurney: Going out further, beyond the immediate crisis, what does the path back to normalcy look like? We’ve spoken about this before. We’re both optimists on the long-term view, but what does that look like as we transition out of the emergency?

Chagla: Our health-care system is going to be exhausted. Our people have been working very, very hard. And even as cases come down and the ICUs decompress, there will still be a huge backlog of procedures we need to get caught up on. So there’s no real rest coming.

But we should look to the British model, which was successful. Maintain public restrictions while vaccinating the hell out of everyone. We can’t just reopen as soon as cases come down, because there’s still going to be that pressure on the health-care system from delayed procedures and remaining COVID patients.

Something that we are going to have to watch very carefully is what happens after we have vaccinated, with at least one dose, a substantial part of the population. We will see cases rise again. But we know these vaccines are effective, even against variants. So there will soon be cases rising without rises in serious illness, hospitalization, and deaths. Hopefully, this current wave will be the last one that really threatens the health-care system. The hospitals have been crying out for years about overcrowding. They are hurting now, but even before, our capacity was stretched. Vaccines will help us get back to normal. And we’ll have to reopen slowly to avoid whiplashing back into crisis. There’s something to be said about not doing a back-and-forth, back-and-forth as we vaccinate. Flopping back and forth makes people suffer more, and not just from sickness. We hurt businesses and people, too. We have to buy time for the vaccines to arrive and then take effect. But this will end, and then we can look at bigger changes we need to make.

Gurney: What does the future of COVID-19 look like?

Chagla: Right now, the vaccines work. This will turn COVID-19 into an outpatient disease, the same way we treat many respiratory illnesses. We might need new vaccines or boosters. But that’s not new. We’re used to that. People will still need to go into hospitals. People will die of COVID-19. But for most of the population, thanks to vaccines and maybe boosters, this will be a manageable illness. You’ll see your family doctor; you’ll stay home until you feel better.

We should look at our hospitals and make them more resilient, because we struggle each year even with seasonal influenza. And I think that’s what this will be. Once the population is largely vaccinated — once everyone who wants a vaccine has gotten one — this will likely be a fairly routine respiratory illness. We will have to stay on guard in case future variants result in huge swings upward in cases and serious illness. We’ll have to be willing to bring in restrictions if necessary. But that’s true of flu, too. Hopefully, this will be the last wave of COVID-19 for a long, long time where we need these major restrictions.

This interview has been condensed and edited for length and clarity.

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