Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Transcript for CDC Telebriefing: Update on Flu Season 2014-15

This website is archived for historical purposes and is no longer being maintained or updated.

Press Briefing Transcript

Thursday, December 4, 2014 at 17:00 E.T.

OPERATOR: Welcome and thank you for standing by. At this time all participants are in listen and only mode. During the question and answer session section, please press star 1 on your phone. Today's conference is being recorded. If you have any objections, you may disconnect at this time. Now I'd like to turn today's meeting to Tom Skinner, Senior Public Affairs Officer, CDC. You may begin. 

TOM SKINNER: Hi, Rebecca, and thank you, all, for joining us today for this telebriefing on an update on this year's flu season as well as discussions about health advisories CDC has put out regarding the potential use of antivirals this coming flu season. With us today is the director of the CDC, Dr. Tom Frieden, who will provide some opening remarks, and then we'll get to your questions. Dr. Frieden. 

TOM FRIEDEN: Hello everyone and good morning. Thanks very much for joining us. We've got some new information on influenza for this year. The flu season is beginning and we are seeing some things that are concerning and that led us to issue a health advisory to clinicians across the country. One thing to understand about flu always is that it is unpredictable. Every season is different with different flu viruses spreading and causing illness. So far, this season influenza A, which is called H3N2 viruses have been detected most frequently and in almost all states. We know that in seasons when H3 viruses predominant, we tend to have seasons that are the worst flu years, with more hospitalizations from flu and more deaths from the flu. Unfortunately, about half of the H3N2 viruses that we've analyzed this season are different from the H3N2 virus that's included in this year's flu vaccine. They are different enough that we're concerned that protection from vaccinations against these drifted H3N2 viruses may be lower than we usually see. Most of the other viruses identified are the same as the viruses covered by the vaccine. We continue to recommend flu vaccine as the single best way to protect yourself against the flu. Vaccine will protect against the strands that are covered in the vaccine and may have some effectiveness against the drifted strain. While vaccination is still important, I want to emphasize a second tool to fight the flu and the complications that flu causes, and that is antiviral medications. Antivirals are not a substitute for vaccinations. Vaccinations prevent flu, but antivirals are an important second line of defense to treat the flu. This year, treatment with antiviral drugs is especially important, particularly for people who are at high risk of serious flu complications or for people who are very sick with flu. It's especially important to get antiviral medicines quickly if you have flu. They work best when you start them within two days of the beginning of flu symptoms, and we strongly recommend that if doctors suspect the flu in someone who may be severely ill from the flu, they don't wait for the results of a flu test before starting antivirals. I'll say a little more about this, and then I'll answer questions along with Dr. Joe Bresee from the influenza division. influenza activity has increased slightly in parts of the U.S. and surveillance data indicates that influenza A, H3N2 viruses have predominated so far with lower levels of detection of influenza B viruses and very few of the H1N1 viruses we've seen a few years ago. During the week ending November 22nd, 91 percent of the approximately 1,200 flu positive tests reported to the CDC were influenza A, and 9 percent were influenza B viruses. As I noted before, of the influenza A viruses, nearly all were H3N2, and of those, about half were antigenetically different from the H3N2 component of the 2014 flu vaccine. These changes can signal that the immune response provided by vaccinations won't protect as well for these viruses, and there's a lot of numbers there. Let me go over them again. What we are seeing this year is largely an H3 year, about 90 percent of the viruses we've typed so far are H3. Of the 90 percent, about half are well matched with the vaccine strain, and about half are poorly matched with the vaccine strain, so for the B viruses, about 10 percent, those are well matched. For half of the 90 percent, they are well matched, but for the other half of the 90 percent, they are not well matched, and we may well see less effectiveness, although there also could be some effectiveness against influenza even for the drifted viruses from the vaccine. The drifted viruses were first detected in March of 2014 after -- when it was already too late to include them in this season's vaccine. At that time, the current vaccine component, the one that's covered, the H3 vaccine that's in the strain, that is in the vaccine, was still by far the most common of the H3N2 viruses. These viruses, both the H3 that's well matched and the H3 that's poorly matched are likely to continue to circulate in the U.S. this season, and there is no way to predict with certainty what is going to happen. We have four different strains of flu circulating: The B strain, the h1 strain, the well matched H3 strain, and the poorly matched H3 strain, and only time will tell which of them, if any, will predominate for the following weeks and months of this year's flu season. Flu always has a potential to be serious, but H3N2 viruses tend to be associated with more severe seasons. The rate of hospitalization and death can be twice as high as or more than in flu season when H3 doesn't predominate. People with certain health conditions like asthma, diabetes, heart disease, lung disease, and pregnancy are also at high risk. We're also noting our hospitalizations for the year, and we know, sadly, that so far there have been five pediatric deaths associated with influenza. We've also heard of outbreaks in schools and in nursing homes. During some seasons when the viruses are antigenically drifted, vaccine effectiveness can be lower, but that's not always the case. If we have a severe season with H3N2 virus predominating, getting a vaccine even if it does not provide as good as protection as we hope would be more important than ever and remains the single most important way to protect yourself against the flu. In addition, a vaccination will offer the usual protection of circulating viruses that have not undergone antigenetic draft. We continue to recommend vaccination, because though far from perfect, it still offers us the best chance for prevention. We can't predict what will happen over the entire season. The influenza vaccine is designed to protect from three or four, depending what vaccine you get, different influenza viruses. Any of these could circulate at any time in the season, and if we have a severe season, getting a vaccine that provides partial protection may be more important than ever, so, first, we urge people who have not been vaccinated to get a vaccine now. Companies have already distributed close to 150 billion doses this year. As I mentioned earlier, antiviral treatment is particularly important this year. Many people believe that since flu is a virus, there's no treatment for it. In fact, there are antiviral drugs that work to reduce the severity of influenza. There are two FDA approved drugs recommended for use in the U.S. during this season, Oseltamivir and Zanamivir. Treatment with antiviral drugs works best when they are begun 48 hours of getting sick, but they can still be helpful in some patients when given later in the course of the illness. Treatments with antiviral drugs for influenza can make your illness milder and shorter. It can reduce the likelihood you'll end up in a hospital or in intensive care, and we believe treatment with antiviral drugs can reduce the risk of dying from influenza. Prescription antiviral drugs, however, are greatly under prescribed, particularly for people who are at very high risk of getting the flu. Probably fewer than one in six people who are severely ill with the flu get antiviral drugs. Very important that we do better for people who are severely ill or who could become severely ill with influenza. That's the single most important message of this telebriefing. We need to get the message out that treating early with the drugs makes the difference between a milder illness or a very severe illness. Time is important when it comes to treatment for influenza. Antiviral drugs are even more important when circulating viruses are different from the vaccine virus. This can mean the vaccine is not as effective in this year as it has been in the past, and that cannot only have more people coming down with severe illness, but also crowding emergency departments and hospitals. I also want to remind people of another defense against respiratory viruses like the flu are simple things like staying home if you're sick so that you don't make other people sick. I'll conclude by reiterating we cannot predict what's going to happen in the rest of the flu season. It is possible we could have a season that's more severe than most with more hospitalizations and tragically more deaths. I want to urge anyone who has not got vaccinated to get vaccinated. It's still our best tool to prevent influenza. I've been vaccinated. My family's been vaccinated. If you have not been vaccinated, get vaccinated. Second, to encourage you if you are sick, talk to your doctor promptly about getting antiviral treatment because that can help you get healthy quicker. Third, take everyday actions like covering your cough and staying home if you're sick. With that, I'll stop, and we'll open for questions. 

TOM SKINNER: Hi, Rebecca, we're ready for questions, please. 

OPERATOR: Thank you, our -- we'll begin the question and answer session. If you have a question please press star 1. Remember to say your name and please unmute your microphone.  Our first question comes from Leigh Ann Winick with CBS news, your line is open. 


OPERATOR: Okay. Our next question comes from Eben Brown with Fox News Radio. Your line's open. 

EBEN BROWN: Thank you, good morning Dr. Frieden, thank you for doing this. Some years back when we had the H1N1 swine flu issue, the manufacturers of the vaccine were willing to come out with separate vaccines for H1N1, if I remember, and to include H1N1 in the general vaccine going forward. Has there been in -- or what's been the result of communications CDC may have had with the drug makers regarding vaccines and getting people vaccinated against this strain, or is it too far in the season to make that happen? 

TOM FRIEDEN: Right. During the H1N1 pandemic, by April, we had the vaccine and could begin the production. Here, we only saw this drifted strain become common in September. By which time the vaccine was already out. Even with the newer vaccine technology, a cell based production; it takes four months to make the vaccine. Essentially, the flu change was too late for the vaccines to be changed. 

TOM SKINNER: Next question, Rebecca? 

OPERATOR: Our next question comes from Liz Szabo with USA today. Your line's open. 

LIZ SZABO: Thanks. I've seen some data showing that there's not a correlation to match the vaccine and the virus and its effectiveness. Do we need a better measure of the vaccine effectiveness? 

TOM FRIEDEN: Each year, we do studies to measure the effectiveness of the vaccine, and we find variability in how effective the vaccine is. They are not easy studies to do because we don't always have the contracting of each patient who has flu vaccine, but the bottom line is that the flu vaccine is our best tool for prevention that the effectiveness of the flu vaccine does tend to vary year to year, and that the drifts that we're seeing may indicate that it may be less effective this year, and that's why we think that it is particularly important that people who are very sick, who are at risk of becoming very sick get antiviral drugs, Tamiflu, promptly. I'd like to turn the question over for a more in-depth answer to Dr. Joe Bresee. 

JOE BRESEE: Yes this is Dr. Joe Bresee. I agree with what Dr. Frieden said. It's clear that the laboratory tests we're using to understand how closely related this virus is to the vaccine virus is are good, but they're imperfect markers of how well the vaccine will function in the field. We'll know that soon. We do study's every year in the field to measure the real life effectiveness of how well these vaccines work in the field. We'll have that data sometime in the middle of the season. We'll know the answer to this. You're right to the extent that these aren't perfect markers of what to expect in terms of how well the vaccine will work, but they are related to how well the vaccine worked. As a note of caution, once we saw the drifted strains, the strains that look somewhat different than the vaccine strains, we wanted to make sure that people knew and make sure that people knew the tools like antivirals they had to medicate the disease and flu. 

TOM SKINNER: Next question, Rebecca

OPERATOR: Our next question is from Dan Childs with ABC news. The line is open. 

DAN CHILDS: Thank you very much for taking my question. With regard to the antivirals, we've seen in past years that sometimes stocks have been somewhat depleted that there have not been necessarily enough. Will they be sufficient this year? What, if anything, is the CDC doing now to ramp up production? 

JOE BRESEE: Yeah, that's a great question. This is Joe Bresee again. We're not aware of any shortages now, and we expect to have enough antivirals to meet the demand this year. Occasionally because the pediatric formulation suspensions are in short supply, we may have shortages in that and sometimes do, but we have ways to get around that by taking the capsules and making a formulation for children. And there are directions for that on the CDC website. 

TOM SKINNER: Next question, Rebecca. 

OPERATOR: Thank you. Our next question is from Caitlin McCabe with the Wall Street Journal. 

CAITLIN MCCABE: Hi, thank you. I had a question. Can you give an update about the shortage in production delays that the vaccine itself that was a problem earlier this year? 

TOM FRIEDEN: We -- other than spot shortages in individual areas that were short lived in the season, we have not heard. For wide spread shortages, we think there's ample vaccine out there. 145 million doses have been distributed by manufacturers, and that should be sufficient for the demand. 

JOE BRESEE: That's exactly right. I have nothing to add.

TOM SKINNER: Next question, Rebecca? 

OPERATOR: We have Mike Stobbe with the Associated Press. Your line is open. 

MIKE STOBBE: Hi, thank you for taking the question. Couple questions. First, clarification, you talked about an antigenetic drift, the H3N2 that's 52 percent of the samples showing positive for antigenetic drift. Are you talking about the type of H3N2 that has been seen before, but just happened to be the one that's most common at the moment, or is this a new type of H3N2 not seen before? Also, can you they more about one in six severely ill people get antivirals, why is it that low, do you think, and I'm sorry, one more. In October, there was a presentation of information that the H1N1 flu mist may not be effective in children. You talked about the flu vaccine being well matched to the other trains, but there's that information there about the flu mist may not be as effective against H1N1 this year. Can you incorporate that in the overview? 

TOM FRIEDEN: Thanks. First, the drifted strains, and those of you who cover flu regularly know, we talk about shift and drift. Shift being bigger changes and drift being smaller changes. This is an example of drift. In March, I believe the first three strains drifted in this way where identified and it was not until over the summer, then in September that we saw them in significant numbers. So this is not something that's been around before. It is as we see that unpredictability of influenza with new strains coming up, possibly as a result of vaccinations where they are escaping the immunity that's being developed. In terms of antiviral use, there are many reasons why it's not used as commonly as it should be used. One of the issues is a misconception you have to test for it first. In fact, many of the tests can have some false negatives, and we strongly encourage doctors not to wait for a test, but to treat if it's indicated to treat. I think it is just a pattern of prescribing, but it's not familiar to doctors to use antivirals for influenza. The benefit is not as marked as the benefit for some bacterial infections where you see a very gratifying resolution of an infection that otherwise would have progressed to show the benefit. It's essentially about a day less of severe illness, and that results in a reduced risk in hospitalization and likely of death as well. In terms of flu mist, we believe that flu mist is likely to be effective against the matched strain this year. We continue to recommend it. It was, as you note, a -- an analysis of one's subgroup that suggested that it may have been less effective against h1 last year. H1 is not prominent this year, but we're working closely with researchers around the country as well as with the companies to try to understand whether that's, in fact, what happened, and if so, why? Dr. Bresee, would you like to add to that? 

JOE BRESEE: In response to the investigation into why the live attenuated influenza vaccine, the nasal spray vaccine, worked less well against the h1 than we expected. There has been lots of evaluation, but for now, the CDC policy remains the same that the children 2 to 8 years old should receive the nasal spray if available when they go to the doctor. We want to make sure that when kids show up to the doctor and the nasal spray is not available, get the shot, get vaccinated with the vaccine, don't try to come back for the nasal spray when it's available. 

TOM FRIEDEN: One other reason why we see low rates in treatments is that unfortunately, people wait to see the doctor. If you're high risk, if you have lung disease, heart disease, diabetes, and you get symptoms, contact the doctor right away. I will say many health care systems increased the availability of antivirals using nurse call lines as a way of patients calling in, having them come into the office, getting assessed over the phone, and then if it is appropriate, getting prescribed and able to pick up antiviral medication that may keep them out of the hospitals. 

TOM SKINNER: Next question, Rebecca. 

OPERATOR: Our next question comes from Julie Steenhuysen with Reuters. Your line is open. 

JULIE STEENHUYSEN: Yeah, hi, thanks for taking my call. Dr. Frieden, I'm curious, I know that you're recommending antivirals and, of course, you want to treat every weapon you have to treat the flu, but I'm wondering what you think about the Cochrane review study -- I think it was in April that suggested antivirals are not very effective when it comes to preventing hospitalizations from flu. How do you balance that? Thanks. 

TOM FRIEDEN: We looked in detail at the data on Oseltamivir. We looked at published and unpublished data. We looked at the full data set, and it is the opinion of the CDC scientists that the evidence is strong. That Oseltamivir given early in the course of illness will reduce the length of illness by about a day. It is not a miracle drug, but we believe it is an effective drug, and we think there's some methodological issues with that review related to what are some of the outcomes looked at, what are some of the sample sizes, what was the data included? There was some concern that not all data had been shared by the company. We have looked at a broad swath of data available, and we see a consistency of the data that does indicate to us that there is some ethicacy of the drugs. Again, they are not perfect. We wish we had better drugs. We wish we had a better vaccine. Right now, the best way to protect yourself against the flu is to get a vaccine. The best way to reduce the length of your illness is antiviral drugs, and the best way to protect other peoples is not to go out when you're sick.

TOM SKINNER: Next question, Rebecca. 

OPERATOR: Next question, Donna Young, Script news. 

DONNA YOUNG: Thank you for taking my question. I was wondering why if you started seeing this significantly in September, you waited until December to make the information available? Also, are you concerned that because you put out this notice last night or late yesterday, that headlines got ahead of your message today? Thank you. 

TOM FRIEDEN: We have been providing this information all along through the mmwr and through a slew of you. Dr. Bresee will go into more details.

JOE BRESEE: Yes, that's a good question. We've been tracking it closely since it emerged in March. In September, we published the mmwr wrapping up the summer season, and we mentioned predominantly in that MMWR that we're seeing it during that May to September period. Globally it accounted for 50 percent of the H3 viruses that were looked at globally. There were not that many viruses still at the time in the United States, and it's not really until now when we're starting to see more flu activity in the United States, that we're seeing a lot of the viruses. So up until now, there's been so little activity it was hard to say that the virus was going to be a public health concern or not. I think now with the increasing cases of flu and that this virus is maintaining a presence and maintaining prevalence in the United States, we felt it necessary to come out and talk about it a little bit because we think antivirals provide a fantastic way to mitigate the disease you might get. 

TOM SKINNER: Next question, Rebecca. 

OPERATOR: Next question from Robert Lowes from Medscape Medical News. Your line is open. 

ROBERT LOWES: Yes, thank you for taking my question. I have two. One, for the 2013-2014 flu season, do you have any figure for the effectiveness of the seasonal flu vaccine, do you have a percentage level of effectiveness, and, second, there was an mmwr report recently talking about an outbreak of this H3 flu virus aboard a naval ship, and 99 percent of the sailors have been vaccinated, but one-fourth of them came down with the flu. Is this an example of the problem with the vaccine being unable to cope very well with the drifted H3 virus strain? 

JOE BRESEE: Yes, good questions, thank you. So, first, the effectiveness question. We presented data a couple times over the summer that looked at last year's vaccines and how effective it was, and, as usual, it was 50 to 55 percent effective overall in the United States last year, the vaccine was. We'll come out next week as a teaser, we'll come out next week with an mmwr that describes what health impact the vaccination program for last year had in terms of averted cases, hospitalizations, and clinic visits. Pay attention to the space next week. The outbreak you're talking about in the naval ship last year was actually an H3 outbreak, as you said; it was not this H3 virus, but a previous H3 virus, the one that was predominant last year. We do see outbreak viruses like influenza on cruise ships, on ships with closed spaces because so many people are crammed together in close contact. It's easy to spread viruses, even among the highly vaccinated population. That was a useful investigation highlighting the importance of flu and naval ships and cruise ships and the importance of using antivirals again in context like that. 

TOM SKINNER: Next question, Rebecca. 

OPERATOR: Next question, Michael Smith, Medpage today, your line's open. 

MICHAEL SMITH: Yes, thank you. Dr. Frieden, you said there were, that there have already been five pediatric deaths. Two questions, one, put it in context, is that high or low for this time period? Secondly, are they linked with the drifted H3N2, or do you know that information? 

TOM FRIEDEN: I'll let the doctor give more details, but each year of the pediatric deaths, we generally find that about 90 percent of the kids had not been vaccinated, so we really do emphasize vaccination as the most important preventative tool for influenza in terms of the five cases, Dr. Bresee will give more information. 

JOE BRESEE: The five children known to die from the flu so far this year, four were infected with influenza A, three of those we've confirmed are H3 viruses. One who died with an influenza B virus. We don't know if the H3N2 viruses the three children had when they died was this virus, the drifted virus, or the other virus. 

TOM FRIEDEN: So, I'll just thank everyone for joining us. Let me wrap up by emphasizing that flu is unpredictable, but what we've seen so far this year is concerning for two reasons. First, that it is likely to be, so far, an H3 predominant season, but that could change. An H3 predominant season tends to have more hospitalizations and more deaths, and, second, that so far about half of the H3 strains have been drifted and there may be a lower effectiveness of the vaccine. It still is essential to get vaccinated. Vaccines are the most effective way of preventing influenza, but we are especially recommending this year that people are severely ill or people who may become severely ill because you have diabetes, lung disease, heart disease, asthma, or pregnancy, see your doctor promptly if you have cough, fever, symptoms of flu, and ask about prompt treatment with antiviral drugs. So thank you very much for joining us. 

TOM SKINNER: Thank you, this concludes our call. Reporters needing additional information can call the CDC Press office at 404-629-3286. Thank you. 

OPERATOR: Thank you, all, for attending today's conference. You may now disconnect.