Hey, it's Floor Lixman and you're listening to Science Friday. The superflu is here and it's wreaking havoc across the nation. Health officials confirm a new strain of the flu is spreading. It's very contagious and it lasts longer. I hear in the United States, the number of children hospitalized for the flu hitting the highest weekly rate in more than 15 years. That's not good. No, it is not good. The so-called superflu has sickened more than 19 million people in the US so far this season. And the flu shot hasn't offered that much protection. So what is going on with this superflu storm? Here to cough up some answers is Dr. Jennifer Dushan, pediatric infectious disease specialist at Mount Sinai Hospital in New York. Welcome Jen. Hi, thank you for having me. Let's talk branding. Is it a superflu? Does that actually mean anything? So that is a little bit sensational. Certainly we've seen a lot of cases of flu and people are sick with it. But in terms of that terminology, we can kind of break it down into case numbers and virulence. So is it a superflu in terms of virulence? So is it causing people to have more severe disease? The jury still kind of out on that. In terms of case numbers, absolutely. We're seeing a lot more cases of the flu this year. You know, I know people who got vaccinated for flu still got really sick. Did the vaccine miss the mark? What happened there? Yeah, so that's really interesting. And that's really one of the reasons why I love my profession because you know, there are always surprises. So the flu vaccine is made in advance of the flu season using a combination of microbiologic and global surveillance data as well as some modeling. Last year's strains are sort of modeled to see how they're going to change. And the yearly flu vaccine is targeted to that strategy. So last year in the US or sort of Southern hemisphere strains that might come our way. Global, global. We have global surveillance data, the WHO, in conjunction with many different nations, actually has biologic data from strains that are collected through various laboratories. And so we're able to do some pretty sophisticated modeling in terms of how global flu strains are going to mutate or change for the next season. So you know, what generally happens, so they make the flu vaccine. And what we what we usually have first is the Southern hemisphere data. That's because their summers are winter or our winter is their summer. So as flu is generally a winter spring virus, the Southern hemisphere sees it first. So everyone as typical got the flu vaccine as they as they normally would in the Southern hemisphere. And what seemed to happen is that one of the flu A strains in H3N2 developed some mutations on one of the antigens. We noticed was this H3N2 strain called subclade K had a couple of different mutations. And so the vaccine that we had developed wasn't didn't really cover this very well. And then it's sort of too late, right? Because the vaccine's already been developed. Right. Exactly. So, you know, I can tell you that because these are mutations and not dramatic shifts, the flu vaccine does still protect against major complications of the flu. That includes severe pneumonia, hospitalizations. So you know, we're still recommending that people get the flu vaccine. But yeah, I mean, flu is tricky. And it's kind of interesting. There are some reports now that are that are showing that the Southern hemisphere is actually having a second peak of flu with this particular what we call subclade. This case, this super K as it's been. Yeah. Yeah. I mean, is the K subclade, is this like a newt wig on the flu family tree? Yeah, that's kind of actually a good way to describe it. So it's within the strain of H3N2. But what happened is a couple of the proteins basically mutated. So the mutated by surprise, which again is a feature of the flu. We know it mutates every year and often we're surprised. For example, we saw an entirely new strain in 2009 that H1N1. This is a little bit different than that. So this isn't an entirely new strain. This is basically just what we call antigenic drift. Some of those antigens have mutated and drifted. You mentioned that the flu shot can still be protective against sort of the most severe disease. Can we get nerdy for a second? How does that work? If it's not a match for K, you know, it's case-upclad. How is it offering protection? Yeah. So those proteins aren't completely changed. So they don't mutate such that the flu vaccine doesn't recognize those and stimulate your immune system to recognize those proteins completely. It's more of a partial protection. And every year, the CDC studies what happened usually at the end of the flu season and reports that. And the H3N2 strain is usually the one that's the trickiest. And this again is the one that had those antigenic drifts. Why is this, why is H3N2 the problem child? You know, probably because again, it seems to have the most ability to mutate and change. That's not a hard and fast rule. But that's the one that we seem to grapple with the most. So there are multiple flu strains that are put in the flu vaccine since the H1N1 came about. We've been including that. There's the H3 strain and there are also some flu B strains. And that's another reason why it's really important to get vaccinated because right now, about 90% of circulating flu strains are this H3N2 subplated K. But that may change throughout the season. Last year, we saw a sort of a late peak of influenza B. And that's pretty well covered by the flu vaccine. Yeah. I mean, is there any hope for solving this mismatch problem? Like, like, universal flu vaccine or a different way of doing things? There's always hope. Although usually I have to say, I'm sort of Debbie Downer. Like I'm the person that you don't want to have at your dinner party. I love Debbie Downer's. You're always invited to my dinner party. We can Debbie Downe together. We can sit in a corner and talk about flu. So yes, unfortunately, some of that research has been put on the back burner. They're interesting, right? So there is a global effort to develop what's called a universal flu vaccine. Some of those efforts involve mRNA technology. Some of them don't. But that's been put on the back burner for the time being, especially in the US, where a lot of our vaccine research has unfortunately been affected by recent changes in the CDC architecture. Well, speaking of that, I mean, earlier this year, the CDC changed recommendations for childhood vaccines and stopped universally recommending that kids get the flu vaccine. What are your thoughts on that as a pediatric infectious disease specialist? Yeah. So that's an unmitigated disaster, huh? So we know that even by the CDC's own data that children have the highest hospitalization rate next to the elderly. So making those recommendations is really grossly irresponsible. And I'm not the only one that feels that way. I think that infectious disease physicians, general pediatricians, anyone who works with children is just really disappointed by those recommendations. Are fewer people getting the flu shot this year? Is that a factor in why we've seen so many cases? It's definitely contributing factor. And yes, the flu vaccine is one of those vaccines that tends to have poor uptake. Anyway, so about 43% of eligible children this season thus far have been immunized. Of course, that's terrible. You know, there are a lot of reasons for that. It's annually. If people are going to skip something, they're going to skip something that, you know, you have to remember to get every year. I really give a lot of credit to the general pediatricians that I work with. They're on the ground and trying to do their best in making sure that everyone comes in for their visit. But it can be challenging. So, you know, also the elephant in the room, or not such an elephant in the room, is that certainly since COVID, vaccine uptake, especially for flu, has been diminished. Yeah. Yeah. And I sort of, I mean, a lot of this renders be speechless, unfortunately. I'm sorry that we got here. And I'm really hoping that it doesn't take a long time to reverse course, but I don't know that that's necessarily the case. Wow. It renders you speechless. Yes, it really does. Say more about that. Well, I'm speechless. So, to Shay. To Shay. Okay. I want to wrap up with a different kind of question. Yeah. You're a doctor. When you go down with the flu, what's your remedy? Rewatching madmen, ginger shots, like what do you do? So I personally prefer to kick everybody out of the room, close the door, not speak to anybody. That doesn't work. Usually what I end up doing is working from home, but we do, by the way, have antivirals that can help shorten the duration of flu if you get it. And you start to take those medications within in a timely manner, can help prevent sort of the really severe consequences of the flu, such as pneumonia, hospitalization, dehydration. So, I've already, I already have my prescription in lock for one of those particular medications. We kind of forget that one of the reasons to test is to be able to use one of those treatments when it was therapies. Okay. So take some medicine and kick everybody outside of the room. Yeah. And one of the TV stations where I live has like 24 or 7 Law and Order Marathon. So that's what I like to do. My husband prefers storage wars, but we have two TVs, so it's fine. Dr. Jennifer Dushan is a pediatric infectious disease specialist at Mount Sinai Hospital in New York. Jen, thanks for joining us. Thank you. This episode was produced by Kathleen Davis. And if you have a question or a comment or something you want us to look into, please give us a ring, 877-4Sypry, 877-4Sypry. The listener line is always open. See you tomorrow. I'm Flora Lickman.
