According to the Centers for Disease Control and Prevention, influenza is the most frequent cause of death in the United States from a vaccine-preventable disease. The 2017-18 influenza season was an intense one, with 172 pediatric deaths recorded.
David Hunstad, MD discusses what we know about the current state of this year's flu season, and what we can we expect before its peak.
Selected Podcast
Flu Facts: What We Know About This Year's Flu Season
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Learn more about David Hunstad, MD
David Hunstad, MD
David Hunstad, MD, is a specialist in Infectious Disease, Pediatric Diagnostics and Pediatric Infectious Disease.Learn more about David Hunstad, MD
Transcription:
Melanie Cole (Host): According to the Centers for Disease Control and Prevention, influenza is the most frequent cause of death in the United States from a vaccine preventable disease, and last year’s flu season was an intense one. My guest today is Dr. David Hunstad. He’s a Washington University division chief and Pediatric Infectious Disease physician at St. Louis Children’s Hospital. Dr. Hunstad, on average how many kids get sick with the flu every year and what is the hospitalization like, how many kids get hospitalized because of the flu?
Dr. David Hunstad (Guest): So the CDC estimates that up to a million individuals in the United States will get hospitalized with flu every year and up to 20,000 of those are kids. We usually see 100 to 150 pediatric deaths from flu each year, and as you said, last year was an intense year. We had 80,000 illnesses and 180 pediatric deaths last year.
Host: Wow, what happened last year, what was the issue that there was so many – what was the issue with the vaccine?
Dr. Hunstad: Well I would say there’s natural variation season to season in how intense the season is, and last year’s vaccine was actually relatively well matched to the strains of flu that were circulating, so I would say even though it was a very busy year last year, it was not really attributable to a failure of last year’s vaccine.
Host: So what do we know about the current state of this year’s flu season and what can we expect before its peak?
Dr. Hunstad: I think it’s hard to say much yet. I will say that flu activity has just really started to creep in in most states in the United States right now. There’s not wide spread activity in really any states. It’s starting to pick up a little more in the Southeast United States, which is typical, and we’re just getting to the point where the next couple of weeks we will see sort of what the slope of our initial epidemic curve will look like. So it’s really hard at this point to predict whether we will have an okay season, a bad season, or a good season this year.
Host: What viruses will this 2018-19 vaccine protect against? Tell us about this year’s flu expectations as far as the vaccine.
Dr. Hunstad: Yeah, so the vaccine, as in recent years, most quadrivalent vaccines have four flu strains, in that two are what are called A strains and two of what are called B strains. This year, the four strains include two new strains that are updated from last year’s vaccine. One is an A strain, the AH3M2 strain, and one is one of the B strains. So far, this year – so every year the CDC will test viruses that are isolated from patients across the country to see how good the vaccine match is, and even though it’s very early in the season this year, the vaccine match appears very, very good. So that hopefully means we’ll have a relatively good flu season this year.
Host: Last year we heard that the nasal mist was not in use. What’s different about this year?
Dr. Hunstad: So the nasal mist, as you know, became very popular after it was released a few years ago because for many people they like to avoid injections, and also there was a little bit of data that in certain populations it might actually work a little better than the flu shot; however, after a few years of that, the efficacy of the nasal mist wore off. It was not as effective two years ago, and so it was temporarily removed from the market. It was off market last year as you said. This year it is just expected to be available late in the season. There’s not much available right now, as the manufacturer in conjunction with some of the regulatory agencies does feel that they have figured out why the nasal mist sort of lost its efficacy, and so it may be available later this season, but the availability so far is not wide spread, and importantly, the American Academy of Pediatrics recommended specifically that pediatricians not choose to use the nasal mist this season for most kids until we once again kind of can see whether the efficacy of that strategy has returned.
Host: What would you like other pediatricians to know, Dr. Hunstad, as an infectious disease physician in pediatrics, what would you like them to know about counseling their patients and their patient’s parents about getting the vaccine and debunking some of those myths? How should they go about that?
Dr. Hunstad: Yeah so I think there are a few things to focus on when talking to parents about flu vaccine. As you said, there’s a lot of misinformation out there, as people come to the office with various ideas about whether to get the flu vaccine or what the risks might be. First of all, I would try to focus on patients and families where there is particular risk for severe complications from influenza. So these might be children who have heart or lung problems, ex-premature babies, patients with cystic fibrosis or asthma who are likely to get very sick if they get the flu, these should be the primary targets for vaccination, and not only the kids, but once again a great way to protect kids in the household is to vaccinate everyone in the household. This is especially true for babies under six months of age who can’t receive flu vaccine, and so it’s really important in those situations to vaccinate the other people in the household, a strategy called cocooning to protect those vulnerable babies. In terms of the myths, I think obviously the most troublesome one is the idea that you can get flu from getting the flu shot, so it is true that a small number of people who get the flu shot will have some very mild symptoms of soreness and maybe a slight fever, but it doesn’t turn into the flu. The viruses that are used in the flu vaccine are killed, they are not live, and they cannot cause influenza disease.
Host: At what point, because sometimes you still can get the flu, at what point would you tell a pediatrician to refer a patient to a specialist in infectious disease?
Dr. Hunstad: Yeah, you’re right that even if you are vaccinated it is still possible to get the flu. The vaccine efficacy of flu shots is, you know in a given year somewhere between 40% and 60%, which is still way better than not being vaccinated, that’s why we recommend it, but it’s not as thoroughly protective as some other vaccines might be for other diseases. So pediatricians are going to continue to see children with flu and flu-like symptoms. Right now there’s actually a lot more other respiratory viruses out there like RSV than there is flu, but once again we expect flu to start picking up in these next few weeks, and they’re going to see a lot of flu. They’re going to prescribe antiviral that’ll help shorten the course of the flu, and pediatricians are very experienced with this, but if they see things that are outside of what they normally see with flu, kids that are particularly sick, kids that are having trouble breathing or they suspect pneumonia, which can be a complication of flu, then those are times when they might want to give us a call or refer a patient to the emergency department or to the infectious disease service.
Host: You mentioned other vaccines Dr. Hunstad, why don’t you wrap up with the importance of vaccinations in general and keeping to the schedule and how do you want other providers to discuss that with their patients, because patients have a lot of questions now about vaccines. What do you want them to impart to their patients?
Dr. Hunstad: I think the important thing is that a lot of myths have been, as you say, debunked. I think the popular ones about autism and other things that were linked potentially to vaccines, those have been disproven, and focusing on everything we know about the minimal risks of most vaccines and the risks of getting these vaccine preventable diseases. So even things that seem like ordinary childhood illnesses, like chicken pox, we need to continue to vaccinate for these, because before vaccination people, including lots of kids, got complications from chicken pox and there were many deaths associated with chicken pox. So even though these diseases are not common now, in part because of wide spread vaccination, they pop right back up in communities where vaccination coverage is not good, and it’s then that we see outbreaks of things like measles, meningitis in children and certainly in those cases you occasionally see some deaths from the vaccine preventative diseases. So these are the kinds of things that we want providers to share with the parents to help them understand the risks and benefit ratio of these vaccines.
Host: Well that’s certainly great information, and I would imagine it’s a little bit frustrating for infectious disease specialists to have to keep repeating this, but it’s so important that that’s what we will do. Thank you so much, Dr. Hunstad, for joining us today. A physician can refer a patient by calling Children’s Direct Physician Access Line at 1-800-678-HELP, that’s 1-800-678-4357. You’re listening to Radio Rounds with St. Louis Children’s Hospital. For more information on resources available at St. Louis Children’s Hospital, you can go to stlouischildrens.org, that’s stlouischildrens.org. I’m Melanie Cole, thanks so much for tuning in.
Melanie Cole (Host): According to the Centers for Disease Control and Prevention, influenza is the most frequent cause of death in the United States from a vaccine preventable disease, and last year’s flu season was an intense one. My guest today is Dr. David Hunstad. He’s a Washington University division chief and Pediatric Infectious Disease physician at St. Louis Children’s Hospital. Dr. Hunstad, on average how many kids get sick with the flu every year and what is the hospitalization like, how many kids get hospitalized because of the flu?
Dr. David Hunstad (Guest): So the CDC estimates that up to a million individuals in the United States will get hospitalized with flu every year and up to 20,000 of those are kids. We usually see 100 to 150 pediatric deaths from flu each year, and as you said, last year was an intense year. We had 80,000 illnesses and 180 pediatric deaths last year.
Host: Wow, what happened last year, what was the issue that there was so many – what was the issue with the vaccine?
Dr. Hunstad: Well I would say there’s natural variation season to season in how intense the season is, and last year’s vaccine was actually relatively well matched to the strains of flu that were circulating, so I would say even though it was a very busy year last year, it was not really attributable to a failure of last year’s vaccine.
Host: So what do we know about the current state of this year’s flu season and what can we expect before its peak?
Dr. Hunstad: I think it’s hard to say much yet. I will say that flu activity has just really started to creep in in most states in the United States right now. There’s not wide spread activity in really any states. It’s starting to pick up a little more in the Southeast United States, which is typical, and we’re just getting to the point where the next couple of weeks we will see sort of what the slope of our initial epidemic curve will look like. So it’s really hard at this point to predict whether we will have an okay season, a bad season, or a good season this year.
Host: What viruses will this 2018-19 vaccine protect against? Tell us about this year’s flu expectations as far as the vaccine.
Dr. Hunstad: Yeah, so the vaccine, as in recent years, most quadrivalent vaccines have four flu strains, in that two are what are called A strains and two of what are called B strains. This year, the four strains include two new strains that are updated from last year’s vaccine. One is an A strain, the AH3M2 strain, and one is one of the B strains. So far, this year – so every year the CDC will test viruses that are isolated from patients across the country to see how good the vaccine match is, and even though it’s very early in the season this year, the vaccine match appears very, very good. So that hopefully means we’ll have a relatively good flu season this year.
Host: Last year we heard that the nasal mist was not in use. What’s different about this year?
Dr. Hunstad: So the nasal mist, as you know, became very popular after it was released a few years ago because for many people they like to avoid injections, and also there was a little bit of data that in certain populations it might actually work a little better than the flu shot; however, after a few years of that, the efficacy of the nasal mist wore off. It was not as effective two years ago, and so it was temporarily removed from the market. It was off market last year as you said. This year it is just expected to be available late in the season. There’s not much available right now, as the manufacturer in conjunction with some of the regulatory agencies does feel that they have figured out why the nasal mist sort of lost its efficacy, and so it may be available later this season, but the availability so far is not wide spread, and importantly, the American Academy of Pediatrics recommended specifically that pediatricians not choose to use the nasal mist this season for most kids until we once again kind of can see whether the efficacy of that strategy has returned.
Host: What would you like other pediatricians to know, Dr. Hunstad, as an infectious disease physician in pediatrics, what would you like them to know about counseling their patients and their patient’s parents about getting the vaccine and debunking some of those myths? How should they go about that?
Dr. Hunstad: Yeah so I think there are a few things to focus on when talking to parents about flu vaccine. As you said, there’s a lot of misinformation out there, as people come to the office with various ideas about whether to get the flu vaccine or what the risks might be. First of all, I would try to focus on patients and families where there is particular risk for severe complications from influenza. So these might be children who have heart or lung problems, ex-premature babies, patients with cystic fibrosis or asthma who are likely to get very sick if they get the flu, these should be the primary targets for vaccination, and not only the kids, but once again a great way to protect kids in the household is to vaccinate everyone in the household. This is especially true for babies under six months of age who can’t receive flu vaccine, and so it’s really important in those situations to vaccinate the other people in the household, a strategy called cocooning to protect those vulnerable babies. In terms of the myths, I think obviously the most troublesome one is the idea that you can get flu from getting the flu shot, so it is true that a small number of people who get the flu shot will have some very mild symptoms of soreness and maybe a slight fever, but it doesn’t turn into the flu. The viruses that are used in the flu vaccine are killed, they are not live, and they cannot cause influenza disease.
Host: At what point, because sometimes you still can get the flu, at what point would you tell a pediatrician to refer a patient to a specialist in infectious disease?
Dr. Hunstad: Yeah, you’re right that even if you are vaccinated it is still possible to get the flu. The vaccine efficacy of flu shots is, you know in a given year somewhere between 40% and 60%, which is still way better than not being vaccinated, that’s why we recommend it, but it’s not as thoroughly protective as some other vaccines might be for other diseases. So pediatricians are going to continue to see children with flu and flu-like symptoms. Right now there’s actually a lot more other respiratory viruses out there like RSV than there is flu, but once again we expect flu to start picking up in these next few weeks, and they’re going to see a lot of flu. They’re going to prescribe antiviral that’ll help shorten the course of the flu, and pediatricians are very experienced with this, but if they see things that are outside of what they normally see with flu, kids that are particularly sick, kids that are having trouble breathing or they suspect pneumonia, which can be a complication of flu, then those are times when they might want to give us a call or refer a patient to the emergency department or to the infectious disease service.
Host: You mentioned other vaccines Dr. Hunstad, why don’t you wrap up with the importance of vaccinations in general and keeping to the schedule and how do you want other providers to discuss that with their patients, because patients have a lot of questions now about vaccines. What do you want them to impart to their patients?
Dr. Hunstad: I think the important thing is that a lot of myths have been, as you say, debunked. I think the popular ones about autism and other things that were linked potentially to vaccines, those have been disproven, and focusing on everything we know about the minimal risks of most vaccines and the risks of getting these vaccine preventable diseases. So even things that seem like ordinary childhood illnesses, like chicken pox, we need to continue to vaccinate for these, because before vaccination people, including lots of kids, got complications from chicken pox and there were many deaths associated with chicken pox. So even though these diseases are not common now, in part because of wide spread vaccination, they pop right back up in communities where vaccination coverage is not good, and it’s then that we see outbreaks of things like measles, meningitis in children and certainly in those cases you occasionally see some deaths from the vaccine preventative diseases. So these are the kinds of things that we want providers to share with the parents to help them understand the risks and benefit ratio of these vaccines.
Host: Well that’s certainly great information, and I would imagine it’s a little bit frustrating for infectious disease specialists to have to keep repeating this, but it’s so important that that’s what we will do. Thank you so much, Dr. Hunstad, for joining us today. A physician can refer a patient by calling Children’s Direct Physician Access Line at 1-800-678-HELP, that’s 1-800-678-4357. You’re listening to Radio Rounds with St. Louis Children’s Hospital. For more information on resources available at St. Louis Children’s Hospital, you can go to stlouischildrens.org, that’s stlouischildrens.org. I’m Melanie Cole, thanks so much for tuning in.