Transcript for CDC Update on Flu Activity

OPERATOR:  Welcome and thank you for standing by. Today’s conference is being recorded.  If you have any objections, you may disconnect at this time all participants will be in a listen only mode until the question and answer mode of today’s call. During the question and answer portion, if you would like to ask a question, please press star one. I would like to turn the call over to Kathy Harben. You may begin.

KATHY HARBEN: Thank you Monae and thank you all for joining us today. There continues to be great interest in this season’s influenza outbreak.  Today we will provide the latest flu view numbers and advice on preventing the flu, and also what people can do to reduce the risk of serious illness. CDC Director Dr. Brenda Fitzgerald is unable to be with us this morning but she has shared an introductory statement and you will hear that shortly. Following Dr. Fitzgerald’s statement, Dr. Dan Jernigan, Director the influenza division in CDC’s national center for immunization and respiratory diseases will provide opening remarks and then address your questions.

DR BRENDA FITZGERALD: The flu season has continued to be challenging and flu has been intense across the United States. CDC’s flu experts will give you details in a moment, but I want to say that I am saddened to tell you that there have been seven more pediatric deaths reported just this week. A total of 37 so far for this season. The most important things to remember are, one, protect yourself from flu by washing your hands often, especially if you are caring for someone who is sick. Protect others by staying home, seeing a doctor if you are sick, and covering your mouth when you cough or sneeze. And remember it’s not too late to get a flu shot for yourself and for your child. Thank you. 

KATHY HARBEN: I want to let everyone know that we will have a transcript of DR. Fitzgerald’s statement in our transcript. I’m hoping you were able to hear that but we will have it transcribed in the final transcript. I’ll turn the call over now to Dr. Jernigan.

DAN JERNIGAN: Thank you very much. It has been a tough flu season so far this year. And while flu activity is beginning to go down in parts of the country, it remains high for most the U.S., with some areas still rising. Most people with influenza are being infected with the H3N2 influenza virus. And in seasons where H3N2 is the main cause of influenza, we see more cases, more visits to the doctor, more hospitalizations, and more deaths, especially among older people. This season now looking like the 2014-15 season where H3N2 predominated. In that season, was categorized as a high severity season. While most people with flu will feel sick, they may miss work or school, but most will recover. However, some people will go on to have more severe illness, including hospitalizations and deaths. To give you a view of what we are seeing with flu right now, let me just walk through the different systems we use to determine where flu is spreading, how much flu is happening this week, and how sever it is. First lets talk about the geographic spread of flu and from that we know that flu is still happening all over the United States. We’ve experienced two notable characteristics of flu this season: The first is that flu activity became widespread within almost all states and jurisdictions at the same time, The second is that flu activity has now stayed at the same level for 3 weeks in a row, with 49 states reporting widespread activity, each week, for 3 weeks. We often see different parts of the country “light up” at different times, but for the past 3 weeks, the entire country has been experiencing lots of flu, all at the same time.  If we look at what is happening at Doctor’s offices and emergency departments we are clearly seeing a lot of people going to see the doctor or being seen in urgent care settings. The number of people going in to see a doctor for influenza-like-illness increased again this week, rising to 6.6%; that means that 6.6% of all people coming into the clinics and emergency departments had influenza-like illness. This is the highest level of activity recorded since the 2009 H1N1 pandemic, which peaked at 7.7%. The rapid increase in cases we have been seeing after the winter holidays and it  is among all ages, but is higher in children. So, it looks like a big part of the later January activity is flu transmission from kids returning to school.  Flu activity has been elevated for 9 consecutive weeks so far this season. To put that into perspective, the average duration of a flu season in the past 5 seasons has been around 16 weeks, with the longest being 20 weeks. So, by this measure, we are about halfway there this season. That means we have several more weeks of flu to go. However, we have some signs that flu activity may have peaked in some parts of the country. California and other states on the west coast are seeing activity begin to go down. Hospitalizations and deaths however may continue to increase as these data are still coming in to those systems there.  The CDC FluView website has region and state-level data that you can review for more information. Let’s now talk about what’s happening in hospitals for those patients who are being hospitalized with influenza. We’ve been tracking the number of people being admitted to the hospital with confirmed influenza infection. For the week ending January 20, the rate of hospitalizations are very similar to what we saw in 2014-15, which was, as I said, a high severity season. This week, we’re reporting 41.9 per 100,000 is the rate for hospitalizations. The rate is about the same as it was in 2014-15. If you go back to the 2014-15 season, for that whole season, the total amount of hospitalizations was around 710,000 so we would expect at the end of this season to have something probably around that number. We also are seeing some states having much more activity than others and we collect this information from only a select number of states. But those we have, we can see that California is around four times more hospitalizations than this same time in 2014-15, Minnesota is about two times that level and New York, we’re beginning to see rises in the amounts hospitalizations. For California, I think it’s important to know that they had at least five weeks where they were at a higher level of activity and so those higher numbers probably reflect having more flu in their community for a longer period of time. The highest hospitalization rate this season, as in most seasons, is among people 65 years and older. Its about the same we saw in 2014-15 but actually a little less than that times. The second most impacted group this season are people 50-64 years of age, with a rate of 44.2 per 100,000. This represents a change from what we have seen in the last several seasons for 2 reasons. First, during most seasons, young children aged 0-4 years have been the next most impacted group after those of age over 65, however, this season, people 50-64 are now in that spot, in other words baby boomers have higher rates than grandchildren right now. Second, the hospitalization rate for 50-64-year-olds this season is significantly higher than what was observed during recent seasons in 2012-13 and 2014-15. When we look at actually what are those influenza viruses that are sending these 50-64-year-olds to the hospital this season, we see that not only is it H3N2 but also the other influenza A virus H1N1 that is contributing to these higher rates. For the younger age groups, the hospitalization rates are either similar to or lower than observed during recent more severe seasons. Let me now talk about what we are seeing from the monitoring of deaths due to pneumonia and influenza in the U.S. right now and what we see is the number of influenza associated deaths have risen fairly rapidly. We’ve been tracking deaths that are due to pneumonia & influenza as their listed on death certificates: These pneumonia and influenza deaths went up sharply to 9.1% this week and they’ve been elevated for three consecutive weeks. For two of the recent H3N2 seasons, 2012-13 and 2014-15 seasons, pneumonia and influenza deaths peaked at 11.1 and around 10.8 percent respectively. So we haven’t reached those peaks yet but it’s still early in the season so we may be getting to those we expect this season to reach or surpass those numbers as the season progresses. As Dr. Fitzgerald mentioned, tragically, this week we also are reporting an additional 7 flu-related pediatric deaths, bringing the total number of flu deaths in children to 37 this season. These deaths are associated with influenza  A(H3N2) and H1N1 viruses as well as influenza B viruses. It is noteworthy that among the influenza A viruses that have been subtyped in these deaths, 65% have been H1N1 viruses. We expect there will be more reports of pediatric deaths, similar to what have seen in more severe seasons. Just a little bit more about the other viruses that are circulating the flu viruses. While H3N2 continue to predominate, other flu viruses are contributing to the season. Some states are actually seeing more H1N1 than other states, and we are also hearing reports of influenza B outbreaks in nursing homes, which is less common for this time of year. While we don’t yet have vaccine effectiveness estimates for this season, in previous seasons, vaccine effectiveness against H1N1 and B viruses has typically been in the 50% to 60% range. In past seasons that are like this one, we have estimated that by the end of this season, 34 million Americans have gotten get the flu. Most of those people this season and then feel sick, but they should stay home from work or school, but most will not need to go see the doctor, and most will recover in a few days. However, some will need to be seen by their doctor or in the emergency department where they may be prescribed antiviral drugs. Especially those at high risk. Those who are at high risk that we recommend to get treated if they get sick with the flu are the very young the very old the pregnant women and those with underlying illnesses like heart conditions and lung problems. In addition, otherwise healthy people can have influenza that goes on to more severe illness, and can have symptoms like shortness of breath and difficulty breathing Chest pain Very high and persistent fevers Ear pain. Those are the things that should lead parents or the individual to go see there doctor where they may be prescribed antiviral drugs. There has been some information out there about antiviral shortages. CDC is in regular contact with influenza antiviral manufacturers regarding supply and other issues. Some manufactures are reporting delays in filling orders and CDC is aware of spot shortages of antiviral drugs specifically for alsotamiver suspension and for generic alsotamavir capsules, these are happening in some places where there high influenza activity. CDC is working with manufacturers to address any existing gaps in the market. I want to remind everyone about our current recommendations. For prevention, CDC is still recommending getting a flu shot. While getting a vaccine earlier in the season is better, there is still a lot of the season to go and vaccination now could still provide some benefit. There is an Influenza Vaccine Availability Tracking System that can help potential buyers locate vaccine still available for purchase. And to do that, folks can go to the CDC website or go to vaccinefinder.org. For treatment, CDC recommends prompt treatment with flu antiviral drugs for people who are very sick with flu symptoms or people who are at high risk of developing serious flu complications when they get the flu. Consider calling your health care provider or pharmacist beforehand if you are looking for vaccine or trying to fill an antiviral prescription. Finally, everyone should take everyday precautions preventing the spread of influenza, like washing your hands, covering your cough if your sick, and staying home from work or school to prevent spreading the flu to others. Thank you and I will be glad to take any questions now.

KATHY HARBEN: Thank you Dr. Jernigan. Monei, we are ready for questions.

OPERATOR: Thank you. At this time, we will begin our question and answer session. If you would like to ask a question, please press star 1 from your phone, unmute your line and record your first and last name clearly when prompted. If you would like to withdraw your question, please press star 2. One moment, as we wait for the first question. One moment. Our first question comes from Helen Branswell. Your line is open.

HELEN BRANSWELL: Thank you very much for taking my question. I have a couple if I could please. Dr. Jernigan, you were talking about the fact that baby boomers are the second most highly affected group this year, the 50 to 64 year olds. I’m wondering if you have any thoughts as to why that would be. Do you know what the vaccination rate is in that age demographic? My second question relates to the fact that this is a very, very active H3 season on top of the pretty active H3 season last year and the very active H3 season a couple of years ago. Do you guys have any thoughts about how we could have so much H3 activity in such a short span of time? Wouldn’t you think that there would be a fair degree of immunity in the population at this point?

DAN JERNIGAN: Thanks. So with regard to the 50 to 64 year olds, the better rates of vaccination of course are in those that are healthcare providers, which represent the 90 range. It gets into the 60’s or so for those who are over the age of 65 and then it drops down below that for those that are aged 50 to 64. We have seen that that’s an area where there are a lot of people and that those folks are the ones that would really benefit from having higher vaccination coverage. These are folks that are at the peak of their careers a lot of times. They are managing a lot of the businesses and so them missing flu is something that can impact not only them and their families, but also those that are in the businesses that they work for. The reasons for that are no exactly clear, but we know in H3N2 seasons, we see more of the influenza cases in those over age 50, especially over age 65. But this year, we are actually seeing, I think H1N1 providing additional contribution of cases in that 50 to 64 year old range. In addition, also we are seeing a little higher in the 18 to 49 year range as well. And so, yeah if you look at the percent of Influenza A in those over age 65, it’s about 90 percent H3, the cause of hospitalizations for over age 65. In that 50 to 64 year old range, it’s about 80 percent. So there’s about twice as much H1N1 proportionally causing disease in the 50 to 64 year olds. Exactly, why that is, there’s a lot of different explanations that probably would be better at a different time. But we have seen that the 50 to 64 year olds and the 18 to 49 year old may be a bit more susceptible to the H1N1 infection. For the H3N2 seasons, yes, I think the point is that we had a very robust H3N2 season last year. It didn’t have the concentration of activity like we are seeing this year. It was spread out over a much longer period of time. The virus that caused it then has had some drift and we’re beginning to see that some, but not a significant drift that would suggest the kind of season we’re seeing this year. It is possible that a number of folks that are getting infected just did not infected last year or the virus has had some change that we have not been able to detect yet that’s actually causing some of those differences. One thing is also it could be the vaccines just don’t do that well against H3N2 and so the immunity that was gathered last year may not be enough to prevent having another wave of J3N2 this year.

OPERATOR: Our next question comes from Mike Stobbe with the Associated Press. Your line is open.

Mike Stobbe: Thank you for taking my call. Actually, I think you just answered my question, which was why if the H3N2 was dominant in last year’s season. It was kind of intense and we have it again this year. Why is this year so much more intense than last year? You kind of got that, but if you have some additional comments. Also, I was just curious about Dr. Fitzgerald’s recorded message. She sounded a little under the weather. Does Dr. Fitzgerald have the flu?

Dr. Dan Jernigan: I think the recording was done in a manner that may have not been the highest level of fidelity, so I cannot comment on the illness. But I believe all that you were hearing was a fidelity issue and not an illness issue. With regard to the H3N2’s, we have had years where H3N2 has had two really significant seasons in a row. 1997, we had on then. 2003 – 04. So it’s not unheard of. It’s just that we had since the pandemic, been seeing an H3 year, an H1 year, an H3 year, etc. So this one is not following that same pattern, but the pattern has been seen before.

Kathy Harben: Next question please.

OPERATOR: Thank you. Our next question comes from Rob Stein with NPR. Your line is open.

ROB STEIN: Thanks for taking my question. About the pediatric deaths, that number, 37, how does that compare to this time the previous year? Is that higher than usual? The same goes with the death rate number that you said it increased to I think to 9.1 percent this week. Can you provide some context for both those numbers?

DAN JERNIGAN: Sure. After the call, you can also go to the CDC FluView website, where you can get to FluView Interactive. You can slice and dice the data in many different ways and look at trends over time if you want. There are some graphs there also that can show that difference very clearly. With regard to pediatric deaths, if you compare what we are seeing this week with the same week that is in the graph in FluView, you’ll see that there’s fewer this week. The thing that’s important about the deaths that get reported in the United States is that it does take time to get to the system where they are collected. So for instance, sometimes tragically, children will die outside of the hospital and those often have to have a coroner report or medical examiner report. Those kinds of things will delay the report and therefore we think backfill the information. So, it’s really hard to compare what’s happening now with reports with what is printed in past seasons for the same week. Either way, the number of reported deaths that occurred at the end of the season in 2014- 15 was 148. So clearly, we anticipate that there will be more pediatric deaths this year. We already have some reports that it will be increased next week as well. So with pediatric deaths, these that are in the graphs and the ones we report again, probably also are an underestimation of the actual deaths that are out there. There may even be as much as twice than the number we have. For the adults, curves that we have in the graphs from the pneumonia and influenza morality reporting system, that data comes from death certificates. You can look and see that the rapid rise that we have in this past couple of weeks, really looks very similar to what happened in 2014-15. With that, it’s possible it may go a little above it. It may peak at the same time. We don’t know right now, but again that information has some of the same lags because of information getting into the death certificates as well.

ROB STEIN: Do you have a total number of deaths?

DAN JERNIGAN: We don’t, partly because the systems that we collect those numbers from only are representative of parts of the U.S. So what we do then is look at the rates, so we can have trends over time. In years where there is an H3N2 that is at that higher level of severity, we have estimated that at the end of the year there were 56,000 deaths. So the H3N2 years are the ones that have the higher number of deaths and that upper level is about 56,000 for the total year.

ROB STEIN: Thank you.

KATHY HARBEN: Before we go to the next question, I would just like to address the question about whether or not Dr. Fitzgerald has the flu. She does not. She actually is traveling and she is on an airplane right now. That is why she is not able to be with us. Thank you. Next question please.

OPERATOR: Thank you. Our next question comes from Lena Sun from the Washington Post. Your line is open.

LENA SUN: Hi Dr, Jernigan. Thanks for taking my call and you did answer some of the questions. We all had sort of the same instinctual reaction when we heard the news. I was wondering though whether you could…this is the highest ILI since the pandemic, but I was wondering also, isn’t this the highest activity that that indicator since 2003-2004?

DAN JERNIGAN: Yeah, it just depends on how you want to do the comparisons. The most recent in that system is the 2009 H1N1 pandemic, but a lot of times people will remove that from comparisons because it’s so atypical. In 2009, the peak was in November and December, so an extremely early peak. Lots and lots of children that were getting sick and going into the doctor. That one was about 7.7. You’re correct that if you remove the pandemic from the comparison then the most recent one would be the 2003-2004 season, which again was one that peaked in late December. It peaked at 7.6. So yes, for seasons the most recent comparison would be the 2003- 04, but in terms of data we collected through this system including the pandemic, it would be since 2009.

LENA SUN: Okay. And just another follow-up. Everybody is interested in the baby boomer part. Do you want to talk a little bit more about the…you didn’t have time in the earlier question, but do you want to address that a little bit more as to why baby boomers seem to be so hard to hit. Do you think compared to the over 65 that they were less exposed to some of these strains as children?

DAN JERNIGAN: Yes, I think you’re getting at the heart of the issue, which is a very complicated scientific issue. It’s a concept called imprinting where the first Influenza virus that somebody is exposed to as a child, has a way of determining how you respond to Influenzas the rest of your life. For instance, in 2009 when the H1N1 showed up and began circulating rapidly, we saw a strikingly low number of people being hospitalized over age 65. That really reflects the fact that those individuals have been exposed to the H1N1 from back in the first emergency in 1918. So between 1918 to 1947 when that H1N1 was circulating, people that were exposed to that one seemed to respond better when this 2009 H1N1 showed back up. So the same thing may be true in the opposite way that people that were exposed after 1947 actually were exposed to H2N2 and H3N2, which are different viruses and that those exposures may make them a little more likely to have problems with H1N1. So there’s still a lot for us to learn about this, but I think it just shows the complicated nature of Influenza that it really depends on a mixture of things: the environment, the virus itself and how it changes, but also the host and the changes that occur as people get exposed to different influenza viruses over time.

LENA SUN: Thank you.

KATHY HARBEN: Next question please.

OPERATOR: Thank you. Our next question comes from Natasha Chen with CNN. Your line is open.

NATASHA CHEN: Thank you so much. I wanted to ask a little bit more about H3N2. We’re talking about years when this is the dominant strain that the illnesses and deaths are more significant. Is there something about H3N2 that makes it more deadly or is it simply a result of what people have been exposed to in the past?

DAN JERNIGAN: H3N2 definitely is one that has intrinsic features about the virus that does make it more likely to cause severe disease. Exactly what the genetic and antigenic features are that make that happen is actually still being investigated now. We know that H3 causing worse disease. Exactly why still needs to be figured out. H3N2 first showed up 50 years ago, so this is the 50^th commemoration this year of the pandemic emerging back in 1968. Since that time, that virus has continued to change. So it’s getting down a path now where it’s gone through lots of changes, but it’s amazing how much it’s able to evade the human immune system still. Also, that this particular virus has lower vaccine effectiveness. The exact reasons for that are still being figured out. We do know that this particular virus, that’s been around 50 years, is very human adapted. So if you try to grow it in eggs, the virus ends up changing in ways that makes it look different than what’s actually circulating out there. Those changes unfortunately lower the similarity to the circulating viruses and therefore that might be impacting the vaccine effectiveness. We don’t know that for certain, but we are trying to understand if in fact having to grow it in eggs is leading to some of the lower vaccine effectiveness. Most of the vaccine that people get given each year is from egg-based manufacturing.

NATASHA CHEN: Thank you. And I just wanted to clarify also we are talking about 9.1 percent. That number, if you can clarify what that is exactly and how that’s calculated?

DAN JERNIGAN: Yeah, so we look at the percent of all deaths that have a death certificate that’s listing pneumonia and influenza as a cause of the death. And we put that numerator over the total denominator of all deaths that are reported for that period of time.

NATASHA CHEN: Thank you. Okay.

KATHY HARBEN: Next question please.

OPERATOR: Thank you. Our next question comes from Donald McNeil from the New York Times. Your line is open.

DONALD MCNEIL: Thanks. Two questions. The first was you went quickly over a number in the middle of what you were saying Dan. It was 34 million? Was that 34 million Americans have had the flu this year?

DAN JERNIGAN: No. It’s a risk at putting those numbers out. So in 2014-15, at the end of the season, we were able to take all of the different surveillance information we have and stitch it together and come up with estimates about the burden. The point there is in 2014-15, which was a high severe H3N2 season, there were 34 million that were estimated to have Influenza. There were about 16 million that were estimated that had to go into the doctor’s office or to the emergency room. There were 710 thousand hospitalization that year. So that’s an estimate that gives us a sense of where we might end up at the end of this season.

DONALD MCNEIL: Do you have any comparison for that number yet for this season?

DAN JERNIGAN: No, we don’t have those. Because there’s such a variation across the season, we actually want to be able to have all of that information so that we can make a better estimate at the end of the year. You’re point is a good one and I think we are looking at ways to have a weekly estimate of those numbers because I think it’s easier for folks to understand.

DONALD MCNEIL: Okay, my second question then. My editors keep asking me is this the worst flu season since…When did you start tracking flu seasons as accurately as you do now with the ILI and everything else so that I can say that it’s the worst flu season since 2003, since 2009 if you don’t count the fact that that’s a pandemic. Is there a way to accurately say that it’s the worst flu year since when?

DAN JERNIGAN: Yeah, so at this point, we don’t know what the season is going to end up like so it’s hard to say, but it’s tracking at the same level as 2014-15, which was the last high severity season that we had. I’m talking about in multiple ways, both activity, as well as, hospitalizations. When you look at elements of our system that look at transmission of disease and then elements of the system that can tell us about how bad the season is from a severity standpoint like hospitalizations.

DONALD MCNEIL: Lena’s question, is it may be worse than 2014, is it may be as bad as 2003-2004 which would be the earliest you tracked.

DAN JERNIGAN: For hospitalizations, the overall rate right now is tracking about the same as the 2014–15 season, except for people who are under age 65. We are seeing more hospitalizations in that group, but the overall amount is about the same as 2014-15. We don’t know. I mean these numbers can change. We may go above the 2014-15 season and so I think it’s a little hard to make some of those comparisons. From an activity standpoint, we’re seeing the most influenza like illness activity since 2009 and for hospitalizations we are seeing about the same rates as we saw in 2014-15.

DONALD MCNEIL: Okay, thanks.

KATHY HARBEN: Thank you. We have time for one more question.

OPERATOR: Thank you. Our last question comes from Sarah Toy from the Wall Street Journal.

SARAH TOY: Thanks for taking my question. So there have been reports about schools closing due to the severity of the flu season. Can you tell us if CDC is aware of that? If you know how widespread these school closures are? And what the vaccination rates are among school aged children?

DAN JERNIGAN: So a couple of things now. In terms of school closures, we know that every year schools close. These are closing of schools not to prevent transmission of flu, but they are usually reactive school closures because a lot of kids have flu and the teachers are out. So they simply close because they are not able to have school. That happens every year. We know in seasons with H3N2 like this one and last season and 2014-15, we see more of those school closures occur. And CDC does have a system that actually can monitor school closures. I don’t have the percentage numbers with me here, but there is a system that we use to monitor school closures around the country. In terms of vaccine coverage, essentially the younger you are, the better your vaccine coverage. You start at the top with kids that are under 18 years of age, down to age 13. So this is kids that are 13 to 17 years of age, 46.8 percent. For those that are 5 to 12 years of age, its 61.8 percent. For those that are 2 to 4 years of age, it’s 66.8 percent. Then for the very youngest, 6 to 23 months old, it’s 75.3 percent. So that’s an overall for under age 18 of around 60 percent.

SARAH TOY: So can you repeat the figure for around 13 to 17?

DAN JERNIGAN: Yeah, 13 to 17 is 46. 8 percent and all this information is on the CDC website at FluVaxView. So we have FluView for influenza disease and FluVaxView, where you can get any kind of combination of the information for vaccine coverage.

SARAH TOY: I just want to quickly follow up. At this point, would you be recommending that schools close because of just how the flu is spreading or do you think that is just not something that they need to be thinking about at this point?

DAN JERNIGAN: So much of influenza is a very local phenomena, so the decisions about what happens with schools is going to need to happen at the local level. So CDC does not have any recommendations for closing schools. Again, school closures at non-pandemic times are usually reactive where the school has to decide that they have to close because they are not able to provide the services.

SARAH TOY: Okay, thank you.

KATHY HARBEN: Thanks very much. Thank you Dr. Jernigan for joining us today and also thank you to the reporters that joined. If you have follow-up questions, you can call us 404-639-3286 or you can email us at media@cdc.gov. Thank you for joining our call.

###
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES