番茄社区

In part 3 of this Instagram Live discussion, 番茄社区 editor-in-chief Jeremy Faust, MD, Katelyn Jetelina, PhD, MPH, and Katrine Wallace, PhD, talk about the state of COVID in 2024, new research on long COVID, and some positive points for the future.

Jetelina is the author of the "Your Local Epidemiologist" newsletter. Wallace is with the School of Public Health at the University of Illinois at Chicago.

Watch part 1 of this interview on measles here, and part 2 on bird flu here.

The following is a transcript of their remarks:

Faust: Let's just talk about [COVID] updates. I'm really interested in the concept of summer waves and why we have these. I think there's a seasonality to COVID, but it's still hardy enough to survive.

Again, I'll start with Dr. Wallace. What are people asking you? What are their concerns and what are you telling them? Because we are in -- I hate saying this -- a different place than we were, but nor is it a non-issue.

Wallace: Yeah, I think there are a bunch of different camps of people, right? There's people that think like, "Oh my gosh, COVID is still a thing? People still test for COVID?" I think there's that camp, and then there are people that have to be cautious because they're immunocompromised or they're disabled and the fact that everybody else is kind of ignoring it is a threat to them and their health and safety.

So it's been very interesting with the kind of questions I get because it runs the gambit of those kinds of extremes. I think people really wonder about data a lot, because we really don't have good data right now. So I try to put data on my page when I have it and when there's something to say from the sources that I have, which are not as good as what we've had in the past.

And Katelyn, I'm speaking to the choir with you because you're probably in the same situation with data. I know the wastewater is increasing.

In terms of why we have summer waves, my guess to this is just that when we get extreme temperatures, it brings people indoors, and it spreads more easily indoors when you're around other people and when you're in enclosed settings. I'm not 100% sure, I haven't done research to show that, but it does seem that when we have times that bring people indoors, it's when we get these waves.

Faust: Yeah. I was doing a little bit of a deep dive on this the past few days -- nothing that I would put in a peer-reviewed publication or anything -- but basically I think what you said is borne out by the data.

If you look at a place like the South, where during the winter it's still warm enough for people to eat outdoors sometimes, and it's really the summer where you have to hide from the elements and go inside. You look at a place like in the South where the summer peaks and the winter peaks aren't that different.

Whereas in a place like Massachusetts where it's like summer outdoors, winter indoors, our winter peaks are much worse than our summer peaks in terms of just hospitalizations and deaths and also, I think, wastewater. So yeah, I think that that's absolutely the case.

Let's talk about long COVID for a second, because I know our readers and listeners and watchers are very concerned with this. Did you see the new paper in the New England Journal from Dr. Ziyad Al-Aly and his team at the VA?

Jetelina: I did. How could you not see it? It was like every headline in every news organization.

Faust: Yeah but this is what we do. But you know, a lot of our audience has a life.

Jetelina: Oh really? What is that?

Faust: So what did you take away from that?

Jetelina: I wasn't surprised. I think that it follows the data we've been seeing, that the risk of long COVID is declining over time, both because of immunity and because of literally changes of the virus. But there's still risk, and we don't know what the future's going to show if we hit some sort of immunity threshold. There's always just going to be this underlying static risk if it's going to continue to decrease.

But I thought it was helpful for the conversation, and certainly answers a lot of questions that people have out there.

Faust: You know, Dr. Al-Aly's team has VA -- Veterans Administration -- data, which gives you a really nice look at risk. It's a high-risk population, I want to say that. Although for long COVID, it's not necessarily the highest risk, right? On one hand I want to say, "Oh, don't extrapolate. This is a very sick cohort of folks," but long COVID doesn't necessarily always hit just old people, and that's what the VA is pretty enriched to have. So, it's interesting.

But I think over the next couple of years we're going to learn a lot more as Medicare/Medicaid claims data come out and we start to do some really cool experiments to look at what's going on. Dr. Wallace, what did you think about this? About that paper or anything else related to this topic?

Wallace: Well, I think that the field of research on this topic keeps being reinforced in different populations, which is really helpful, right? We have the RECOVER studies that have shown the same thing. We've shown and adults, and now we have this other population of mostly senior men. So it seems to be replicated in all these different populations, which is hopeful.

This one attempted to actually quantify the percent of avoidance that was due to the vaccines, which was kind of cool. It was something like 72%. Every study has its limitations and its strengths, right? You have to be a little bit critical when you're looking at any type of study, no matter what it is.

One thing about database studies when you're talking about COVID is when you say there's a group that had COVID and then a group that didn't have COVID, it's a little bit hard for me to believe that that group didn't have COVID. At this point for me, I'm like, "Well, maybe they just didn't have it bad enough to go to the doctor and they're not getting diagnosed."

Faust: That is a huge point.

Wallace: Yeah. So that's the only -- like I said, it is replicating other studies, so I tend to believe it -- but that's a huge limitation of database studies on COVID particularly.

Faust: Alright. Dr. Jetelina has to jump off. It's probably the White House or something like that. But you can find Dr. Jetelina at "Your Local Epidemiologist" everywhere, on Substack and [Instagram]. Thanks for joining us.

Hop off Katelyn, and Dr. Wallace, you, and I can stay for another minute because that last point I think really does warrant an extra go-around.

I really respect Dr. Al-Aly and his work.

Wallace: Oh, same, absolutely.

Faust: We're friendly and we talk a lot.

But I think that the comparator group in research is everything. And as you said -- we know for a fact that up until the Delta era, we were probably missing half to 75% of cases. We didn't have tests. And then in the Omicron era, when people started doing rapid tests we probably missed -- in terms of public documentation -- it could be most cases.

Wallace: And I remember that was shocking too, that there was nowhere to call and register your positive test or whatever. Remember that?

Faust: Right. And then people were like, "Oh my gosh, rapid tests are problematic because we want to know where the virus is." And people like me would say, "Well yes, on the epi side that's true, on the epidemiology side." But on the "give people news they can use [side]" and that way they can call their doctor if they need Paxlovid or something like that, it's better to have instant results at your fingertips.

So we know, for example, that we missed a lot of cases. Therefore -- and this is the point you're making -- in a study that compares people who had COVID to people who didn't have COVID...

Wallace: There was 4.7 million in the control group so that's...

Faust: We know that a lot of those people actually had COVID and it was mild. If they were put into the COVID group, it would really, really decrease the rates of long COVID.

So I always say that no matter what the rate of long COVID is, it's a serious deal. Because no one thinks it's 0.1%, but even if it were 0.1%, even if it were one in a thousand, it would still be hundreds of thousands or millions of cases. But I think what people still question is, "Is it in the double digits? Is it even in the single digits?" Based on, they look around, they know a hundred people and who has [long COVID]. But I think that the answer is that it's a big enough problem, regardless.

Wallace: Yeah. And the problem, why we don't have great numbers in terms of prevalence is that there's no one clinical case definition of long COVID that exists. Every health agency has their own definition. There's like 10 different definitions. The CDC has one, the WHO [World Health Organization] has one. Right now there's an initiative by the NIH to harmonize the definition.

So depending on what definition each study used, or even things like how much time is considered "long"? These things matter when you're doing a systematic literature review and a meta-analysis. Because if you're combining studies with all different methodologies and all different clinical case definitions -- it's garbage in, garbage out, you know?

Faust: Yeah. And I will say that I addressed the National Academy of Sciences work group on this like a year ago and...

Wallace: Oh, National Academy Sciences, right.

Faust: And they came out with a definition that the CDC basically adopted immediately. But the issue with that definition is it's very broad and inclusive because they don't want to miss any cases.

The problem there is it becomes harder to study therapeutics when you're not distinguishing between subtypes or when basically they don't want to miss anyone. So it's pretty broad.

Wallace: It's not specific.

Faust: Exactly. There's this idea that inclusive is good, but it makes it harder to study. And so I think we see this.

Hope for the future, someone asks -- before we go, can we have hope? Yes. Let's give them hope.

Wallace: End on something positive!

Faust: Here's my favorite line. "Well, if we can't end on a positive note, maybe you can just give them two negatives." No.

Wallace: I have some positive stuff!

There's nasal vaccines that are under development for COVID, which is really exciting because that could theoretically have a little bit more effect on transmissibility and mild illness. So that's kind of an exciting time. Hopefully the trials will go well.

They're also working on combined flu and COVID vaccines for people to get them both at the same time, which I think is great too. So I think there are a lot of exciting developments right now that will hopefully lead to a brighter future with all these things in the fall.

Faust: Yeah. And I'll end on a weirdly, strangely positive note, which is that I am way on record of saying that I think Paxlovid [nirmatrelvir-ritonavir] was like a lifesaver in the pre-vaccine era, and that now I'm not quite so sure. I mean, there are some people who need it.

But the good news is in all the studies looking at Paxlovid, the rate of hospitalization and mortality in the placebo groups, or the group who didn't get Paxlovid, is so much lower than it was 4 years ago. And so, while we're not done with this -- and again, a small number multiplied by 330 million Americans, or a small percentage multiplied by 8 billion humans is a lot, is still a major problem -- the order of magnitude of risk walking into a room has gone down.

Wallace: I just want to make sure people understand the point you just made, because I think it's really important.

In a highly controlled study, he's saying that people that were not medicated with antivirals with COVID still had a much lower rate of severe illness like hospitalization and death. Which means our baseline risk of those things... like population immunity and the vaccines we've had in the past really have worked to protect us moving forward. I think that is a really key point that you just made.

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