MS. DIANE REHMThanks for joining us. I'm Diane Rehm. This year's flu season started early and is hitting hard. Joining me in the studio to talk about how this year's outbreak compares to previous years and what flu vaccines can and cannot do: Dr. Kavita Patel with the Johns Hopkins University School of Medicine and the Brookings Institution, and Dr. Donald Milton of the University of Maryland.

MS. DIANE REHMJoining us by phone from Florida is Dr. Michael Osterholm of the Center for Infectious Disease Research and Policy. Feel free to join us with your own questions, comments. Call us on 800-433-8850. Send us your email to drshow@wamu.org. Follow us on Facebook or send us a tweet. Good morning to all of you.

DR. KAVITA PATELGood morning.

DR. DONALD MILTONGood morning.

DR. MICHAEL OSTERHOLMGood morning.

REHMGood to have you all. And now, first, before we begin our conversation with our guests, let's talk with Dr. Thomas Frieden. He's director of the U.S. Centers for Disease Control and Prevention. Thanks for joining us, Dr. Frieden.

DR. THOMAS FRIEDENThanks very much for having me. Great to be here.

REHMTell us about this year's flu season, how it's different from or similar to what you've seen in the past.

FRIEDENWe're seeing an early flu season with lots of activity. It started in the south and southeast. And the strains of flu that are circulating, which generally change from year to year, have a predominance of what we call H3N2. It's one particular strain of flu that does tend to be associated with more moderate to severe flu seasons, and that is, so far, what we're seeing.

FRIEDENSo we've seen a lot of flu activity earlier in the year than we generally see it. We've seen lots of people going to doctor's offices, to hospitals. And we know that in a -- even in a moderate or severe flu season, we can have hundreds of thousands of hospitalizations for flu and unfortunately, many thousands of deaths. So we encourage...

REHMIs there any clear reason as to why this particular season is so severe and so early?

FRIEDENThere's not really any clear explanation of why flu changes. What happens is that each year, people around the world developed immunity to the circulating strains of flu and the virus then evolves to a different strain that will escape that immunity and infect people the next year.

REHMSo how good a match was this year's vaccine to what you're seeing in the way of the flu?

FRIEDENSo far, we have gotten it just about as right as it could be gotten. Of the strains of flu that are circulating, about 90 percent match the strains that are in the vaccine. The current vaccines have three different flu strains in them. And fortunately, with the global collaboration, because we track flu strains all around the world that helps us in this country, with that collaboration, we were able to accurately predict which three strains would be the most common and to include them in the vaccine.

FRIEDENAnd as I say, they cover about 90 percent. Interestingly, in another year or two, we'll have flu vaccines that have the ability to have four different strains, two of what are called the influenza B viruses. And in this case, that would have allowed us to reach about 100 percent. But covering the strains doesn't mean it's 100 percent effective. The flu vaccine is not nearly as effective as many of the childhood vaccines that we have, but it's still, by far, the best tool we have to prevent the flu.

REHMYou know, I'm interested because I've heard reports that the vaccine this year has been only about 60 percent effective, and yet you're saying 90 percent.

FRIEDENSo let me be clear about the difference because on the one hand, about 90 percent of the strains that are circulating are covered by the strains that are in the vaccine. But when you get the vaccine, it's not 90 percent or 100 percent effective. Some vaccines are. Some vaccines get -- effectiveness is up well over 90 percent.

FRIEDENBut the influenza vaccine doesn't work as well as other vaccines. On average, in recent years, it's been about 60 percent effectiveness preventing hospitalizations, deaths and severe illness. That's far from perfect. We wish it were better. Research is going on now to try to identify better flu vaccines. But it's still, by far, the best tool we've got today to prevent flu.

REHMAnd what about reports of people who received the vaccine who are also getting the flu?

FRIEDENWell, this is one reason that we encourage people who do have flu symptoms, even if you've gotten the flu vaccine, if you have flu symptoms and you're either severely ill or you have an underlying illness that may make you more susceptible to being severely ill, see your doctor early because treatment with antivirals can make a big difference, can help shorten how long you're going to be sick.

REHMIs it too late even now to get the injection?

FRIEDENNo. There's still time to be vaccinated, although it takes about two weeks for the vaccine to become effective to -- for you to build up immunity after getting the shot or inhaling the inhaled formulation. There are still parts of the country, particularly in the West, where we're still seeing steep increases, and we don't know how long this flu season will last. Generally, the peak flu season lasts for about three months, and we're only a little bit a month into it. So there's still certainly time to get vaccinated. But if you're going to do it, do it soon.

REHMDr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, thank you so much for joining us.

FRIEDENThank you.

REHMAnd turning to you, Dr. Patel, what are you seeing in your practice this season?

PATELWe're seeing a lot of healthy young adults coming in with flu symptoms, and they're very surprised because they're a part of the young, invincible population that doesn't get sick and also doesn't happen to get immunized. So we're seeing an uptake in that. And also a lot of elderly patients who have other diseases like diabetes, asthma and other lung issues who are coming in and getting hospitalized. And you probably saw what's happening in Boston where the mayor has declared a public emergency because they've had a tenfold increase in the number of patients.

REHMDr. Osterholm, are there truly concerns about a pandemic this year?

OSTERHOLMWell, first of all, pandemic events are ones that occurs when a new strain of influenza emerges and then leaves a large part of the population vulnerable to it. That's not the case this year. And I think even this year there's really been a misunderstanding of what's going on with influenza. Clearly, influenza, any year, even in a moderate year, can cause lots of illness and deaths and hospitalizations. But I think this year there's been a certain hype in the media about what's happened with it.

OSTERHOLMAnd what I mean by that is we've seen these stories where we've seen these patients coming into medical care facilities around the country. But, you know, the idea that in Boston they went from 70 to 700 cases, they have four deaths and they've declared a public health emergency, a lot of that has to do with the fact that we have really taken out any excess capacity in our health care system. And so even when there's a slight bump in the road, we can quickly be overwhelmed.

OSTERHOLMWhen we're talking about really severe flu, we're talking about hundreds and hundreds of hospitalizations and hundreds and hundreds of deaths, even thousands. And so I think that this year we have flu going on, which is bad. We've had people die from it, unfortunately. But we also have a norovirus going on, a virus that causes vomiting and diarrheal illness.

OSTERHOLMAnd we're also seeing, in some communities, another illness in young kids called RSV, respiratory syncytial virus, which is causing a number of hospitalizations. So I think that flu is obviously a very critical issue. I think this year we do have some real problems. But I don't think it's nearly as bad as what has been portrayed in the media. And most notably, if you look at our -- what we call pneumonia and influenza deaths in this country, we are not seeing it this time, a severe flu season.

REHMAll right. And, Dr. Milton, I understand there's still a great deal of debate about exactly how the flu is transmitted. Talk about that.

MILTONWell, that's true. The literature has, today, contrasting opinions. There have been, in top journals, diametrically opposed opinions about the relevance of aerosols versus direct contact and large-droplet spray, which is when someone coughs directly on you as opposed to just contaminating the air and breathing contaminated air. And we really don't know what the proportion is between these different modes. And that's most important in years when there aren't vaccines.

REHMWhen there are no vaccines.

MILTONWhen you have a brand-new strain emerging...

REHMI see.

MILTON...and like in 2009, most of the peak of the pandemic went by before the vaccine could be widely distributed.

REHMDr. Patel, do you think that there is a lack of understanding, not only among patients but among physicians themselves?

PATELThere's definitely -- because of the early onset of the season, I think a lot of physicians were surprised to see some of these cases. And I've had many conversations with my own colleagues about during which time period antivirals are appropriate. As Dr. Friedman mentioned, you have to get in early in order to really benefit from an antiviral medication.

PATELAnd I think that for most clinicians, the early onset has thrown us off. But I would say that almost all the physicians I've worked with, pediatricians all the way through hospital-based physicians are watching because they have been seeing these cases come through.

REHMYou'll be interested to know that just before we went on the air this morning, we had a call from a person who is on his way to see the doctor about his own flu and had a call from the doctor's office canceling the appointment because the doctor was out sick. So it is very widespread. Short break here. We'll be right back.

REHMWelcome back. Two physicians are here in the studio. Dr. Donald Milton is professor at the Institute for Applied Environmental Health at the University of Maryland. Dr. Kavita Patel is an internist at the Johns Hopkins University School of Medicine. She is also at the Brookings Institution. And joining us by phone from Florida: Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy.

REHMHere is the very first email we have from Mike in Jacksonville, Fla., who says, "It seems like just a few months ago, the media was running stories about how great and powerful this year's flu vaccine was and promoting the use of it. Now, we're inundated with reports of the worst flu season ever. It does not exactly encourage my trust in the vaccines. What happened?" Dr. Osterholm, you believe that the flu vaccine has not been as effective as it could be.

OSTERHOLMYes. Thank you. First of all, let me just come back and re-emphasize the point I made earlier that, yes, this is a flu season and, yes, people are getting sick and many people are getting sick and people are dying. But this is not a severe flu season. Severe flu seasons would be many thousands of people dying. And so we just have to help put that in context because that's why we worry about flu because as bad as this is and as much as it's stressing the health care system, it could be a lot worse.

OSTERHOLMIn terms of the vaccine, our group has been very actively involved looking at the impact of flu vaccine on disease for some time now. And we've issued several major reports on that issue. And the bottom line is, as Dr. Friedland said earlier, it's not a perfect vaccine. It's the best tool we have, and we should use it. But number one is that our group has really brought forward the data to dispel the idea that there really is such a thing as a match.

OSTERHOLMToday, we don't know how to match the vaccine. And, in fact, in data that'll be forthcoming in the next day, we'll show that for the current influenza A vaccines, the ones that are fighting against the more severe form, what we're seeing of the flu today even in young healthy adults, is probably going to be about half the time as helpful, meaning that about 55 percent protection. Whereas if you're talking about the influenza B side of it that Tom also mentioned, there is more protective.

OSTERHOLMNow, what's interesting about that is in influenza A, there's a very close match right now by the definition of how we match strains. In influenza B, there's a very poor match. Almost half the strains that are included in the study are strains that are not in the current vaccine and yet is protecting better. So I think that the idea that there's a match is something that we're all in the influenza world revisiting and realizing that that has been oversold as a way to predict how well the vaccine is going to work. And those data are also been found in Australia, Canada and other parts of the United States.

REHMThat's very interesting. Oversold, would you agree, Dr. Patel?

PATELI hesitate just with sending a public health message that the vaccine -- sending a message to listeners that we should not think of the vaccine as effective. I do think what Dr. Osterholm is trying to point out is that our vaccine is not perfect. It's never been perfect.

REHMNo perfect matches. Yeah.

PATELBut that we do need to send a strong signal that vaccination, especially for the purposes of what we call herd or community immunity, is still critically important.

REHMAll right. Dr. Milton.

MILTONWell, in College Park, Md. where we're doing a study of flu this year -- and we have been recruiting subjects to come in early on in their illness and test them and of the people that we've recruited who actually have influenza based on our lab tests, all of them didn't get the vaccine. The people who are coming in with flu-like symptoms but are actually infected with RSV and maybe a strain of flu B, those people are the ones who had the vaccine. And it's a very small fraction.

MILTONSo from our data so far, it looks like the flu vaccine is working, that the people who are turning out from my study -- and I want to pitch that to your local listeners. They can go to our website, gotflu.org, to volunteer if they're coming down with a flu now. The people that are volunteering who have the flu are the people who didn't get the vaccine yet.

REHMAll right. Doctor...

OSTERHOLMDiane, I think this is really the important point here, if I could just interrupt you.

REHMSure.

OSTERHOLMI want to be really clear. Dr. Milton's study is really not in the position to really make the kind of definitive comments about how well the vaccine is working. I would just urge the audience to hold on. The CDC, and to their credit, are funding some very well-done vaccine effectiveness trials around the country. And they're going to report on that data in the next 24 hours.

REHMGood.

OSTERHOLMAnd those are the data that I'm referring to that show that only about half the time is the vaccine working for influenza A. Let me be really clear. I'm not saying that we shouldn't use it. I think it's the most important tool we have.

REHMSure.

OSTERHOLMI'm very supportive of using influenza vaccine. What I'm saying is the media and others have really pushed the idea of match. And there are those of us in the flu world who have been working on this that find that, in fact, there really is no good correlation between what we call match and how well the vaccine works. We have years when the match is really good, like it is this year.

OSTERHOLM2009 when the pandemic strain was available and we had vaccine for that towards the end of it, in both cases, the vaccine only worked about half the time in young, healthy adults. Those were the closest matches we've had in decades whereas we have like this year with influenza B where the match is really very bad. And yet the vaccine is working much better than we'd ever expect. It's working better than where we have the close match. So all the point I want to make is that we have oversold the idea that match predicts how well the vaccine will work.

OSTERHOLMThat is different than saying we've oversold the vaccine. We should get the vaccine. We need to get the vaccine. And we need to report in the kinds of studies like you'll be hearing about tomorrow that are well-done population-based studies that actually look at vaccine effectiveness. And that -- those data are coming.

REHMAll right. Here's an email from Anne, who says, "There's been something going around locally -- by the way, she's in Indiana -- going around locally with severe vomiting and diarrhea which seems to be very contagious. But I'm not sure that qualifies as flu, though I've heard it referred to as a GI flu." I know that we heard of the norovirus. Tell us about that, Dr. Patel.

PATELThese are viruses and they're classified as intestinal flu-like viruses because they are one -- number one, viruses, and, number two, the way they're transmitted has similar properties to what we consider the seasonal influenza virus. But they're not the same viruses. So, yes, they're all viruses. But they're not all the same.

PATELAnd we're also seeing in a number of patients coming in that have been, for several months now in different parts of the country, like in Indiana and in the Midwest, with intestinal symptoms. But it's important to know that that's distinct and different from the H3N2-type virus...

REHMI see.

PATEL...that's causing the seasonal flu that we're discussing this morning.

REHMYou know, I was on a ship several years ago where the norovirus just went all the way through, everywhere.

PATELEverywhere, right.

REHMDr. Osterholm, tell us about research on a universal vaccine.

OSTERHOLMWell, one of the things that our group has done is just release a report this past October, which is kind of cradle-to-grave analysis of influenza vaccines. And we believe that, you know, the current vaccines that we have, which really date back to the 1940s, were using the same kind of antigen or material to make the body respond to protect us against flu that we use back then. We're doing some work to make more of that antigen faster in larger quantities.

OSTERHOLMBut we really haven't fundamentally changed that. It's like putting a 1940s transmission to a 2012 car. And what we're looking for are better vaccines that will get us the much better protection. One of the things that's not mentioned and hasn't been mentioned is the place where the vaccine works the very least is in those over age 65. So if we talk about 55 percent largely in young adults, when you get to the older population, it doesn't work even nearly as well as that level.

OSTERHOLMAnd that's important because that's where 90 percent of the deaths occur. The vaccines we're talking about would be the kind that, in fact, are based on what happened in 2009. In 2009, we had individuals who had been exposed to a very similar virus as the pandemic virus back in the 1930s and '40s when that circulated. Then it disappeared. Well, yet in 2009, these people we're now over 65, and you would think that if their immune systems were beginning to weaken, they should've had the least protection.

OSTERHOLMYou would also have thought, boy, if I'm still protected 60 years after the fact, that's pretty remarkable. And yet they were. We had clear and compelling evidence in 2009. These people had protection because of exposures they'd had to a similar virus many, many years before. So we're trying to figure out how we can mimic that kind of natural protection that we found there that isn't the same as what we're getting with our current vaccine in other parts.

REHMDr. Patel, what are your thoughts on that?

PATELI think it's a very interesting point about trying to confer some sort of longer term immunity. But what we're seeing, Diane, is not just unique to the influenza virus. We're seeing a lot of this in the bacterial resistance in our community as well. We're seeing bacteria and viruses and super bugs, infectious disease agents that are outwitting the best of our science in terms of being able to develop not only a vaccine, but also pharmaceutical agents and medicines that can treat those viruses and bacteria.

PATELSo I love the idea of having a one-shot virus vaccine, but I'm also looking at the science and what we've seen in the fields of epidemiology and public health. And that is going to be quite challenging to do, but a great aspiration.

REHMAnd then let's move on from vaccine to treatment. Here's an email from John in Dallas, who says, "How does Tamiflu work compared to a vaccine, and does Tamiflu change from season to season as does the vaccine?" Dr. Milton.

MILTONTamiflu works by -- that's a really good question. Tamiflu is quite different than the vaccine. The vaccine is a preventive. Tamiflu is a treatment. It's something that interferes with the virus being able to propagate itself from cell to cell in your body. And so to be really effective, you have to take it very soon after you become infected, and it's not something that you can just take once like a vaccine and be protected for the rest of the flu season. It's a treatment.

REHMAll right.

MILTONThis year, the viruses are reported by CDC to all be sensitive to Tamiflu, and that was not always true about five years ago. We had some viruses that were almost all resistant to it.

REHMSo do you recommend Tamiflu to your patients, Dr. Patel?

PATELAs Dr. Milton mentioned, you have to take the medicine early, and unfortunately, by the time they're coming to the doctor, it's been several days because, as you probably know, the instinct is, I've got a cold. I'll fight it. Oh, wait a minute. It's something worse than that. I got to call my doctor to get an appointment, and then it's day three, day four, day five.

PATELSo I am definitely recommending it for some of my vulnerable patients who have other diseases, elderly or some of the really young patients that have other issues. But by the time I see most people in the clinics today, it's already a little too late.

REHMDoes Tamiflu create nausea?

PATELTamiflu does have some GI side effects, and that's been one of the things that I warn patients about. And there's also some controversy about the evidence of Tamiflu and some of the other drugs. A recent study from the Cochrane Collaborative, which looks at a large trove of evidence and science, last year said that the drugs like Tamiflu are as effective or just marginally more effective than a placebo.

PATELSo it's not necessarily -- I had a patient last week, 23-year-old healthy woman two days into the flu. She was -- she tested positive in our clinic with her rapid saliva for the influenza virus. So she has influenza. We don't know what strain, but we sent that off to the public health department. And I said to her, you know what, you're healthy, and you're taking Tylenol. We're controlling your symptoms. I'm not sure you need the antiviral medication in that particular case. So we're handling it on a case-by-case basis.

REHMInteresting. And you're listening to "The Diane Rehm Show." And joining us now by phone from Philadelphia, Dr. Leonard Friedland. He's vice president of GlaxoSmithKline's North America Vaccines Clinical Development and Medical Affairs. Thanks for joining us, Dr. Friedland.

DR. LEONARD FRIEDLANDIt's my pleasure. Thank you for having me on the show.

REHMHelp me to understand how vaccine companies decide which strains to use in each year's vaccine.

FRIEDLANDAh. That's a fantastic question. It's really a testament to the public health community and the tremendous surveillance systems they have in place. Each year, upwards of 100 different centers all around the world collect influenza specimens that come into their laboratory, and then five particular research locations around the world work with the WHO, the World Health Organization.

FRIEDLANDThese are centers in Atlanta, Ga., London, Melbourne, Australia, Tokyo, Japan and Beijing, China, and they further characterize the influenza strains that are being reported all throughout the year. Then in approximately February, the World Health Organization gets together and reviews all of the science that are coming in from all of these surveillance laboratories, and they look to predict what type of influenza strains are likely to cause disease in the subsequent season.

FRIEDLANDAnd then they make a recommendation. They have been recommending a vaccine to have three strains, two A strains and one B. In the future, we're going to have vaccines that have two A strains and two B strains, and we can come back to that in a few minutes if you'd like. And when they make this recommendation, then each individual country around the world makes a final decision on how to formulate their vaccine.

REHMHa.

FRIEDLANDIn the United States, that is made by the Food and Drug Administration.

REHMInteresting.

FRIEDLANDYes.

REHMOK. And there are many, many people who are wondering whether the flu vaccine can cause the flu.

FRIEDLANDThat's a great question, and the answer is no. The inactivated flu vaccine, the injectable flu vaccine, cannot cause influenza. It is what's called an inactivated vaccine. It's not live. It just exposes the individual to the proteins that the body then responds to to make an immune response to fight off infection should they become infected. So the vaccine cannot cause influenza when given the inactivated flu vaccine.

REHMSo interesting that many people have reported that, you know, within days or weeks of getting the vaccine, they get the flu. How does that happen?

FRIEDLANDWell, I think what's happening there is that there's a lot of illnesses circulating throughout the year, particularly right now here in the winter months. As was reported by the other speakers, we're seeing not only influenza circulating in the community, but we're seeing respiratory syncytial virus, pertussis, which can cause respiratory symptoms, norovirus, other diseases. So there may have been other things sort of cooking that patients will be coming down with, and they just happen to have had an influenza vaccine around the same time.

REHMAll right. And...

OSTERHOLMDiane, could I just come in on this? Because I think this is an important point. This really...

REHMVery quickly, sir.

OSTERHOLMYeah. This really highlights why we need new and better flu vaccines. Half the population isn't protected when they get vaccinated, and that's the average, meaning that there's a higher proportion of those who are older and lesser proportion of those who are young. We still expect if you use 120 million doses of vaccine in this country, 60 million people are going to be vaccinated...

REHMAll right.

OSTERHOLM…but still vulnerable to the virus.

REHMAnd Dr...

OSTERHOLMSo I want to point out that we still see flu in vaccine recipients, and that's important to understand.

REHMAll right. And, Dr. Friedland, one last quick question. Yes or no, is thimerosal an ingredient in the flu vaccine?

FRIEDLANDSome influenza vaccines have thimerosal as a preservative when those vaccines are produced in vials that contain multiple doses.

REHMSorry. We're out of time.

REHMAnd welcome back. As we talk about this year's flu season which has come early and hit hard, on the line with me right now is Dr. Leonard Friedland. He's vice president of GlaxoSmithKline's North America Vaccines Clinical Development and Medical Affairs. Just before the break, Dr. Friedland, I asked you about thimerosal. Talk about why that is necessary in the vaccine and whether you believe that the presence of thimerosal may actually discourage people from using the flu vaccine.

FRIEDLANDThank you. There are some influenza vaccines that are formulated with thimerosal.

REHMWhy?

FRIEDLANDThose are the vaccines that are supplied in multiple vaccine doses. So let's say one vial will have 10 doses of vaccine. To keep that vial sterile as the vaccine vial is used, it needs to have a preservative, and thimerosal is the preservative that is used.

REHMBut you know as well as I do how many people are very, very leery about thimerosal. Was there any way to produce the vaccine with another kind of preservative other than thimerosal?

FRIEDLANDNo, there is not. There is no other preservative that is available to be used to produce multiple dose vaccines. Many, if not most, of influenza vaccines provided in the United States are provided as single dose vaccines, and therefore, they do not need a preservative, and those vaccines are not formulated with thimerosal.

REHMDr. Patel, have you had resistance from patients?

PATELYes, we have, and I'm glad that he brought up the point that most of the vaccine supply, including what we use at Johns Hopkins, has been largely single-dose vaccines. So we try to educate and reassure people, but I think we still see -- a recent study in The Lancet showed that only about 30 percent of adults even in a normal year including this year, so far, are getting the vaccine. So we still have a lot of resistance for very different reasons

REHMAll right. Dr. Friedland, I hope you'll stay on the line with us. We've got lots of callers. I'm going to open the phones now first to Billy in Dallas, Texas. Good morning. You're on the air.

BILLYHi, Diane. Thanks for taking my call.

REHMSure.

BILLYI have really two quick questions. The first one is, when it comes to death, what does the flu actually attack in the body to cause it? And again, if you can give me a flu for dummies version of it, that would be great.

REHMSure.

BILLYAnd second, based on what everybody's been talking about, I started feeling aches today, so I'm actually going to the doctor. One of the things I want to know is my family -- I have my daughters and everybody else -- what can they do with somebody in the house to maybe aside from just staying away from them, what can they do to not get it?

REHMGood questions. Dr. Patel, what causes death from flu?

PATELSo death is always caused by the virus creating kind of -- in a flu for dummies version, death is generally caused by multiple organs or other areas of the body being involved and then having other infections like pneumonias and bacterial infections because the flu has attacked the body and created what we call kind of a depressed immune system. So think of it as the flu gets in there, and then other things take hold and other organs get involved.

REHMAll right. And Dr. Milton, what can he do to protect his family?

MILTONA couple of things. One is hand washing. Washing your hands, they're washing their hands. Flu doesn't live very long on the hands, but it lives longer on the surfaces. And the other is that flu couldn't live for hours in the air, and you can reduce the contamination of the air in your home by your wearing a surgical mask.

REHMHow about opening windows, opening doors?

MILTONThat can help too in diluting virus, and we don't know how much it helps. But makes sense to try that.

REHMAll right. Here's an email from Karen for Dr. Friedland, who says, "My husband and I were both given the flu shots for the first time this year. We were told by CVS, the drugstore, that we were both receiving the stronger version of the vaccine since we were in our 70s. We were told the vaccine we've received had a double B virus component. Are there different versions of the vaccine?" Dr. Friedland.

FRIEDLANDYes. Thank you. There are a number of different varieties of the influenza vaccine that are available for the U.S. public, vaccines that can be given inhalationally, intradermally, intramuscularly. And there is one particular vaccine, which is not a vaccine from the company that I work with, that vaccine has a higher dose of each of these three antigens currently in the vaccines, the two A strains and the B strain.

FRIEDLANDThat vaccine is only approved for people who are elderly, and it's unclear if that vaccine offers any additional protection compared to the regular vaccine. The Centers for Disease Control does not have a preference for any particular influenza vaccine. The most important thing is that the public be vaccinated annually against influenza.

FRIEDLANDNow, there are opportunities for continued improvements in the seasonal influenza vaccines. One improvement is coming next year from multiple manufacturers, including GlaxoSmithKline, where there will be not only two A strains but two B strains in the vaccine. And we hope that that offers an opportunity to offer improvement in vaccination and protection for the U.S. public.

FRIEDLANDAnd it's also important to point out for the listeners that GlaxoSmithKline and other manufacturers as well do not want to create any barriers for influenza vaccination. And so if people cannot afford influenza vaccination, they should speak to their doctors and visit the websites of the vaccine manufacturers to look for opportunities for patient assistant programs. The goal here is to improve the rates of vaccination throughout the U.S. public.

REHMAll right. And to Jackson, Mich. Good morning, Sarah. You're on the air.

SARAHHi, Diane. Thanks for taking my call.

REHMSure.

SARAHI was calling with, I guess, well, two -- I guess, two questions. The first one is that I, actually, am in Michigan, and we here in Michigan, I guess we're one of the few areas of the country that really has not been hit hard yet by flu. And I wondered if your speakers have any comment on why that might be. And then my second, I guess, maybe it's more like a comment, is as I said, I work for a pharmaceutical company -- I didn't say that, actually.

SARAHI do work for a pharmaceutical company -- one company that does manufacture a flu vaccine, as a matter of fact. And I think it should be mentioned that while flu vaccine is absolutely important and critical, particularly for people who are at higher risk, that not everyone is necessarily higher risk. Healthier, you know, young adults or middle-aged people aren't necessarily certainly at the same risk as other populations.

SARAHAnd there are many people, particularly health care workers that work in hospitals, doctor's offices, et cetera, which, you know, who I come into contact with who are required to get flu vaccines or else their employment is threatened. Yet, the flu vaccine, it has to be said, is not without risk. So I think that the fact they're required to get the vaccine when they may be opposed to it and yet, you know, if they don't do it, their employment is threatened, that is -- that can be a real issue.

REHMAll right. Dr. Osterholm, what's your reaction?

OSTERHOLMWell, first of all, again, we come back in the bottom line message from this show in general is get your flu vaccine. It's the best tool we have to protect against influenza, but it's only a partially effective tool and we know that. I know that may be hard for people to hear because they think somehow we've been taking our message a different direction. We're not. It's only pointing out that's why we need better flu vaccines.

OSTERHOLMIn terms of health care workers, having been the state epidemiologist in Minnesota for many years where I had to make the kinds of recommendations and react to the kinds of public events that occur, we always try to make our recommendations proportional. The data that supports that vaccinating health care workers really makes a difference in terms of transmission to patients is actually seriously flawed. That's been demonstrated. That's been written up recently.

OSTERHOLMNow it makes good sense we should tell health care workers to get vaccinated. We do. But I think mandating vaccination is another issue because I could mandate sick health care workers stay home from work. If half of the health care workers won't respond to the vaccine, I could mandate all health care workers to wear mask. The influenza only makes up a small part of what is actually gets transmitted potentially in a health care system.

OSTERHOLMThere's other respiratory agents, so I think that bottom line message is get vaccinated health care workers. You should get vaccinated. But if you oppose it, I think that that's a real problem to take this to a mandated standard when there are lot of other things we could mandate, with which we have better data (unintelligible).

REHMDr. Milton, do you want to comment?

MILTONI think there is debate about the veracity of the data, how valid it is that shows the protective effect. There are certainly a number of studies, particularly among nursing home workers in the U.K., that demonstrated important protective effects of vaccinating health care workers. And it's on those studies that these mandates are based.

REHMBut what about losing one's job if one doesn't get vaccinated, Dr. Patel?

PATELI think we have a policy at Johns Hopkins where all health care workers are required to get the flu shot, so...

REHMInteresting.

PATEL...we've also had a policy in place. I can tell you, though, that there is no such thing as an entirely never policy. So there are allowances if there are religious or other personal beliefs, but it's up to the health care worker to then voice that opinion. But we've got a blanket policy requiring health care workers to receive the shot.

REHMAll right. To Leicester, Mass. Good morning, Christie.

CHRISTIEGood morning, Diane. Thank you.

REHMSure.

CHRISTIEI am calling because my husband and I, we are both in our 60s. I'm 69. He's 67. He's been vaccinated for the flu. I have not. We have tickets to a play in Boston this weekend that we've been looking forward to. When we go into the city, we usually use public transportation. We travel on the MBTA trains, and we've heard about the current situation with the flu in Boston. And I'm calling to find out whether your experts think it's a good idea for us to use our play tickets and travel to Boston this weekend or should we avoid the city?

REHMDr. Patel, your recommendation?

PATELWe are nowhere near a stage where you have to panic about what the caller is talking about in terms of a mass gathering or mass transit. That's -- those are certainly not -- I would not feel like you need to completely stop your daily living. I do, however, think that your listener should just be very cautious about doing her own hand washing, making sure that, as Dr. Milton mentioned, that anything -- that if they feel like their -- themselves getting sick, coughing, that they take their own protective measures for them self.

PATELAnd I think that's probably the best takeaway point is to just kind of make sure that you're practicing your own personal hygiene. We are not at a stage that we need to worry about mass gatherings or upcoming inaugural, mass transit in the Metro. We do not want to create that kind of public message at this time.

REHMAll right. To Chapel Hill, N.C. Good morning, Kim. Kim, are you there?

KIMKim, I am. Thanks for taking my call.

REHMOK. Sure.

KIMI have a question. One of your speakers mentioned that during the 2009 flu season the elderly population had some immunity because of exposure to a prior flu. And my question is, if we're vaccinating young healthy adults year after year at a time when they could really handle getting the flu, are we setting them up to have less immunity when they're elderly and when you're caller -- you guest had said the flu vaccine was least effective?

REHMThat's interesting. Dr. Osterholm.

OSTERHOLMYes. We don't really have any evidence that that actually happens where we're somehow setting them for more severe flu. We do have evidence today that the vaccine that we use call the live attenuated vaccine -- you puff up the nose -- is actually very effective in children because they don't have any previous immunity, young children. But when you get to be an older child or young adults, even though the vaccine is licensed in that area, we cannot find one study that supports that that's a highly effective vaccine.

OSTERHOLMAnd in part because your immunity does kick in by the time you're either been infected or been vaccinated as a young child and you develop some immunity in your nose so that when the vaccine is actually administered, it actually aborts that vaccine strain growing in your nose and creating that. So that's the one example we have where there is some age-related immunity that could have some impact. That's why we tell kids to get the FluMist but not the older adults to get the FluMist.

REHMInteresting. All right. And you're listening to "The Diane Rehm Show." And to Los Angeles, Calif. Terry, you're on the air.

TERRYOh, hi, Diane. Oh, my gosh, I'm such a big fan. I listen to you every day.

REHMThank you.

TERRYSo, yeah, I am one of the people who is resistant to taking the flu vaccine, and mostly because I -- I'm really against the general marketing of the pharmaceutical industry in ads, on television with, you know, take this and it'll help you sleep, take this and it'll make you happy, all these sort of quick fix, pill-popping society we've created.

TERRYTo me, it just feels like the flu vaccine -- well, I know that it's legitimate for, you know, a certain population. It just does feel like it's being force-fed on us and, you know, pharmaceutical companies are going to make billions of dollars. And why is the government not encouraging us to eat right and sleep well and...

REHMAll right. Dr. Friedland, do you want to comment?

FRIEDLANDYes. Thank you. The United States government is encouraging the population to keep itself healthy, to undergo preventive health care and to visit with their doctors both to prevent illness and to treat illness. And influenza is part of that whole big picture. We know that vaccination is the best tool to prevent a disease that affects a large swath of the population every year and producing many, many thousands, if not hundreds of thousands of hospitalization and many tens of thousands of deaths each year.

FRIEDLANDAnd so vaccination against influenza is an important public health tool, and it meets the goals of the U.S. Public Health Department for what we want to do for our U.S. population.

REHMAll right. And one final question for you, Dr. Patel. Please explain the herd health. Some -- this is an email from Jennifer, who says some of her friends who work in public health talk about it. Could you do that briefly, please?

PATELSure, very briefly. The concept of herd immunity is so that we can kind of create a firewall for the viruses that we're worried about, in this particular case influenza. By the majority of a community getting a vaccine, we are able to circulate antibodies and then also have a way to be resistant to the very viruses at a community level.

REHMDr. Kavita Patel, Dr. Donald Milton, Dr. Michael Osterholm and Dr. Leonard Friedman, (sic) very, very useful, interesting program. Thank you all so much.

PATELThank you.

REHMAnd thanks for listening, all.

MILTONThank you.

REHMI'm Diane Rehm.