Freakonomics Radio - 191. Why Doesn’t Everyone Get the Flu Vaccine?

Episode Date: January 8, 2015

Influenza kills, but you’d never know it by how few of us get the vaccine.

When I say the flu, you say you think what? So I think there's a lot of different uses of the word flu. I think of the virus influenza, but I know that a lot of people confuse it with, you know, respiratory infections as well as gut infections. Everyone thinks the flu is the flu, a cold is a cold, but really the reality is that there's so many different viruses that cause these respiratory infections. So influenza, you know, there's a few of them and they're just a subset of all the different viruses. That's Jeff Kwong. I'm an epidemiologist and a researcher at the Institute for Clinical Evaluative Sciences, and I also practice as a family physician at Toronto Western Hospital in Toronto.

And we are talking about the flu today, the influenza variety of the flu, because A, it is flu season, and B, the flu is really worth talking about. Influenza definitely causes many deaths every year. In the U.S., it's been estimated, you know, so the problem is that there's such a wide range. Some years are very mild and some years are very severe. So I think it averages something in the order of like 10,000 to 20,000 deaths each year. It also causes probably 10 times more hospitalizations, causes lots of visits to emergency departments and to physician offices. It also causes a lot of people to take time off

from work or school. So it's been estimated about somewhere between 5 and 10 percent of the population will get infected by influenza each year. In terms of when it happens and how it happens, can you talk about that for a minute? Why is influenza season or flu season flu season? And how does it actually work its way through a population? I think those are very good questions that we don't have all the answers to just yet. We do know that, you know, generally influenza season falls somewhere between November and March, generally. Exactly when it's going to happen is very unpredictable. So some years it starts late, January or February.

Some years it starts earlier, so as early as sometimes late November or early December. And so what exactly causes it? We don't actually know. We think that it might be related to weather. It seems that, you know, especially in countries like Canada and the US, when it's colder, that seems to promote influenza circulation. So between colder temperatures and lower humidity seems to contribute to that. And then why does this stop all of a sudden, when it only infects about 5% to 10% of the population? I don't think there's anyone who knows the answer to that. If we look at influenza statistics in the southern hemisphere,

where the winter is the opposite, do we see the same thing there? They get it in their winter, not in their summer? Exactly. So the people who are monitoring influenza activity, they monitor both the northern and southern hemisphere to see what's going on. Okay. All right. So you say it is a cold weather phenomenon. Is it actually, do we know anything about whether it's related to the actual weather or more related to the fact that during cold weather, there are more people inside in cramped spaces, etc., etc.? Yeah. So I don't think we have the answer to that either. That's sort of a theory that we have.

You know, what we do know is that closer to the equator, influenza viruses are circulating year-round. It's not just because of cold weather, because there's a lot of these tropical countries where it's just circulating all the time. So no offense, but it sounds like you guys don't really know all that much about influenza yet. That's right. Yeah.

From WNYC, this is Freakonomics Radio, the podcast that explores the hidden side of everything. Here's your host, Stephen Dupner. Influenza, one of the many diseases that we lump together when we say the flu, is indeed a bad disease, especially if you're very old or very young or pregnant or if you have a chronic medical condition like diabetes or heart disease. Influenza is a common cause of pneumonia. The Centers for Disease Control, when cataloging death by cause, groups together influenza and pneumonia. This pairing is perennially in the top 10 causes of death in the United States. In 2010, the most recent year for which there are final data, influenza and pneumonia killed 53,826 Americans, which is more than six times the number of worldwide deaths last year from Ebola. And those are just the influenza and pneumonia deaths that we know of.

That's right. So the biggest problem is that we don't do testing that often. That's the epidemiologist Jeff Kwong. So a lot of people come into hospital, you know, they may have a fever, you know, they may be coughing. And, you know, we think, oh, maybe this person has pneumonia. So we do the chest x-ray and we say, oh, this person has pneumonia. And then we, you know, treat them with antibiotics and we leave it at that. So oftentimes we don't bother doing the testing for exactly which bug

or pathogen is causing the illness. And so a lot of times influenza goes undetected. And the other issue is that influenza often triggers other events. So for instance, you know, a lot of people can get, you know, influenza infection, you know, they feel sick for a few days, but that's what triggers their heart attack or their, you know, their MI. And so then they end up in the hospital because of the MI and, you know, the influenza infection may have passed already and may not have been detected. Influenza has been particularly bad this winter. The CDC says that influenza and pneumonia deaths are at epidemic levels.

In one week last month, for instance, they accounted for nearly 7 percent of all deaths in the United States. One problem is that influenza comes in a variety of strains which change from season to season. And so even though there is a yearly flu vaccine that we all hear about, there are a number of vaccines, actually, the pharmaceutical scientists and health officials who create these vaccines have to make an educated guess very early in the season as to which strains of influenza they'll be able to protect against. This year, for instance, there's one strain doing a lot of damage. For those of you keeping score at home, it is vaccine is not 100% effective. On average, it's more like 60 or 70% effective. But still, a fairly effective vaccine against an illness that can easily kill you or that can kill your more vulnerable loved ones if you give it to them, who doesn't want that vaccine? Turns out, a lot of people don't want that vaccine. So in last year, overall, it was 46%. In children, it was higher.

It was close to 60%. In adults, it was lower at about 40%. So as a family doctor and as a public health guy and as an academic researcher, what would you like the influenza vaccine rate to be? Do you want it to be 100%? I don't think we'll ever see it at 100%. But I mean, if possible? Oh, yeah. I think that would be ideal. We want as many people vaccinated as possible.

I think the more people get vaccinated, then the more herd immunity there is. So the less chance that you would transmit to somebody else if you can't get it. So why don't more people get the influenza vaccine every year? We asked a bunch of people this question. We got a lot of different answers. Number one, it's a hassle to get the vaccine, especially because you have to get it every year. Did you get a flu shot this year? I did year. Did you get a flu shot this year? I did not. Did you get a flu shot this year?

No, I didn't. I did not get a flu shot. I have had the chance to. Honestly, it was a time thing. It wasn't really a conscious decision. It was more that I was busy the day they were giving them out at work. I don't know. You know, I just don't really feel like it's necessary.

And I just had other things to do that day, and I just have never faced the consequences of the decision. So I thought about going to Walgreens and getting one. It's horrible, though. I don't, I mean, I don't think it's the right thing to do. I wouldn't tell my children to do what I'm doing. Jeff Kwong again. So I think the trickiest thing is, you know, influenza, you know, how it reproduces. It's very sloppy. And so it just makes a lot of imperfect copies of itself. And because of that, it's constantly what we call drifting.

It's constantly mutating. And so that's why every few years there are these new strains that come out that are different enough from the ones that we have in the vaccine. And that's why we have to get vaccinated every year so that we can keep up with these, you know, changing viruses. So that's the real pain, right? So it's not like other vaccines, you know, you get it once, you get one series and then you're done for the rest of your life. Reason number two that only 40% of adults in the U.S. get an annual flu vaccine. Does it even work?

All the articles about how it's not that effective this year, and I always get sick anyway, even when I do get it. So I am not convinced that they actually quite work. So I just don't feel the need or I don't feel the urgency to get a flu shot unless there's some major epidemic and it's strongly urged. She has a point. 60 or 70 percent effective just might not seem like it's worth it, especially if you're not very old or very young or pregnant or medically vulnerable.

But if you decide to forego the flu vaccine, it's easy to persuade yourself that you're making a logical decision when, in fact, your brain may be tricking you a bit. Well, it's known as the availability heuristic.

Frederick Chen is an economist at Wake Forest. And so that means the more salient or more vivid something is, the easier it is for us to recall. For instance, if we see an earthquake happening in the news, then somehow, because that's very vivid, we tend to overestimate the probability of an earthquake occurring. Chen has a particular interest in epidemiology. And so I think the problem with vaccination in the end comes down to this. When it's working, it's not very memorable. It's more newsworthy when we see things not working.

But when a vaccine is working, nobody wants to talk about it. Nobody's going to go out there and write a newspaper article about a vaccine. Oh, it's working, you know? Here's a third reason a lot of people don't get the influenza vaccine. They think it actually gives them influenza. I worked in health care for seven years, and I always had to get a flu shot. And every time I got a flu shot, I got the flu really bad and I ended up feeling horrible. And when I didn't get one, I was fine. So I just never got one.

I asked Jeff Kwong about this. One reluctance I've heard, even from among health care workers, is that I don't want to get the flu vaccine because it will give me the flu. I'm told that this is a false concern because this is a dead vaccine, but maybe I'm wrong on that. So clear that up for us. So the injected vaccines are definitely dead. So those are just virus particles that have been put in there. So it's impossible to get influenza infection from the injected vaccine. And so what a lot of people get is they either get another

virus, you know, they picked up rhinovirus or a different virus, and they think that that was influenza. But also a lot of people, especially the first time they get their influenza vaccine, their body's mounting an immune response, and they can feel sort of flu-like symptoms for the first 24 hours or so. So it's not full-blown influenza infection, but it is something. Now, if you're the kind of person who thinks that the influenza vaccine may give you influenza, then you may also subscribe to the fourth and perhaps most interesting explanation for why our flu vaccine rate is so low. I asked Jeff Kwong about this. It's natural for you to make the argument that you would like universal vaccination for something like

influenza. On the other hand, there are a lot of people who consider vaccination even for something potentially a lot more devastating for the average person than influenza. They don't like that idea at all. So there's a, I don't know about a growing, but a prominent strain of what might be called vaccine paranoia. So talk to me about that for a minute. So the term that we use is vaccine hesitancy.

And there's a range, there's a whole spectrum from the people who are, you know, absolutely refuse all vaccines to people who will get them, but they're kind of not sure that they should be getting them. And so, you know, I think that's one of the biggest challenges of people who are, you know, public health officials and other members of the healthcare community, is that I think there's this growing sentiment that, you know, vaccines, you know, are a dangerous thing. And it's a conspiracy of, you know, government and, you know, the pharmaceutical industry. You know, they're just out to make money.

Vaccine hesitancy, vaccine paranoia, whatever you want to call it. It only gets worse when people hear a vaccination story like this one. In the beginning of 2011, the CIA asked Dr. Afridi to launch a hepatitis B vaccination campaign that would focus on a certain neighborhood of Abbottabad in order to get inside these houses, but specifically to get inside one house to find out whether Osama bin Laden was there. That story is coming up on Freakonomics Radio. And also, now that we know why people don't get the flu vaccine, what are we supposed to do about it? A lot of people will go, they're just more for it for the chocolate bar, and they don't mind getting vaccinated while they're

getting their chocolate bar. And one more thing, if you don't already subscribe to this Freakonomics Radio podcast, well, I think you should. It is free at iTunes or wherever you get your podcasts. We will not even stick you with a needle. From WNYC, this is Freakonomics Radio. Here's your host, Stephen Dubner. Mark Mazzetti writes about national security for The New York Times. He shared a Pulitzer Prize in 2009 for the paper's coverage of U.S. involvement in places like Pakistan and Afghanistan. And he wrote a book. The book is called The Way of the Knife. The subtitle is The CIA, a Secret Army and a War at the Ends of the Earth.

It's about what I call the shadow war, the war outside of the declared war zone since the September 11th attacks in places like Pakistan and Yemen and Somalia. And how the CIA has taken on a central role in this secret war the United States has been waging. Mazzetti writes about a Pakistani doctor named Shaquille Afridi. Well, according to Afridi's account, he was first introduced to his first CIA handler by the country director of the organization Save the Children. Now, Save the Children, I should add, has vehemently refused that it did so knowing that Afridi would start working for the CIA, that they had any role in this. But by Afridi's account, he met someone from the CIA at a dinner hosted by the Pakistan country director of Save the Children. Save the Children was doing a lot of work in Pakistan.

They were doing broad health work inside of Pakistan, not just vaccinations, but other work to better the conditions of Pakistani children. According to Mazzetti's reporting, the CIA recruited Dr. Afridi to do some vaccination that was not connected to Save the Children. He did lead a number of vaccination efforts around Pakistan from around 2009 on. He was sort of the perfect spy for the CIA. He could move around Pakistan. He had reason to be in places where Americans couldn't go. And he was able to get access by launching these vaccination programs. And he was very willing to take the CIA's money for his efforts. Eventually, Mazzetti says, the CIA asked Afridi for some help in locating a certain fugitive. In the beginning of 2011, the CIA asked Dr. Afridi to launch a hepatitis B vaccination campaign

that would focus on a certain neighborhood of Abbottabad in order to get inside these houses, but specifically to get inside one house to find out whether Osama bin Laden was there. The CIA suspected that bin Laden and his family were living in this house, but they were hoping to confirm the suspicion with DNA evidence. Nobody expected bin Laden was going to agree to a vaccination, but if they could get possibly, you know, relatives, children, they could find DNA that they could link to bin Laden was going to agree to a vaccination. But if they could get possibly, you know, relatives, children, they could find DNA that they could link to bin Laden. So they go about doing this. The CIA gives Dr. Afridi a handsome sum to begin the campaign. And they never were successful. Afridi and his team went to the house. That house was the one house that refused vaccinations for the people inside of it.

And so at the end of the day, they were never able to confirm through this that bin Laden was living in that house in Abbottabad. On May 2, 2011, he was killed by U.S. forces. Today, at my direction, the United States launched a targeted operation against that compound in Abbottabad, Pakistan. A small team of Americans carried out the operation with extraordinary courage and capability. No Americans were harmed. They took care to avoid civilian casualties. After a firefight, they killed Osama bin Laden

and took custody of his body. The U.S. government had not told the Pakistani government that it was going to show up in the middle of the night and kill bin Laden. This infuriated the Pakistani government. So after the raid that kills bin Laden, the Pakistani government tries to go hunt down anyone who might have helped the United States, specifically the CIA, working inside Pakistan to have tried to find him. So as I write about in my book, right after the raid, Shaquille O'Freedy's CIA handler meets him and gives him some money and a bus ticket to Kabul to go over the border into Afghanistan, basically to escape. He doesn't think

that he's in any danger. And so he does not flee to Afghanistan. He stays. But then he's shortly picked up. He's thrown in jail. And then pretty amazingly, several months later, the CIA director at the time, Leon Panetta, gives an interview that goes public about Afridi, confirming that he had worked for the CIA and really demanding the CIA had enlisted a Pakistani doctor to try to gather information under the cover of a vaccine program. Well, that was very bad news for anybody else out there who was still running a vaccine program. Everyone doing this work was immediately viewed with suspicion not only by Pakistan's government, but also by militant groups who were suspecting that the area was crawling with Western spies. You see a shutdown of the organization Save the Children, which was linked to Dr. Afridi, and they had to close down their work inside of Pakistan. Save the Children had been vaccinating Pakistani children against polio.

They had to stop. Eventually, the Pakistani Taliban banned polio vaccinations entirely. And a number of health workers were directly targeted by groups like the Pakistani Taliban. That's right. It became very dangerous to be a health care worker in Pakistan administering polio vaccines. Since December of 2012, at least 65 such workers have been killed. As a result, you've seen an increase in polio in Pakistan with the vaccination efforts shutting down specifically on polio. There's now a rise in polio in Pakistan when health workers had for a time belief that they had really eradicated the disease inside of Pakistan.

In 2014, there were more than 260 new reported cases of polio in Pakistan, the highest number in 15 years. For the global public health community, that's a big problem. It's an even bigger problem since it seems to have been an unintended consequence, at least in part, of the CIA's covert vaccine program. Now, how have public health officials reacted? With great anger, there already was concern that anyone working, especially for Western organizations, that they might be under suspicion for being spies. this kind of an effort tied directly to the CIA, the anger came from the fact that everyone is really painted with a broad brush as being spied and that these programs would be shut down and the people who are doing this work would be specifically targeted. In January 2013, the deans of 12 top public health schools in the U.S. sent the White House a letter.

It read, While political and security agendas may by necessity induce collateral damage, we as an open society set boundaries on these damages. And we believe this sham vaccination campaign exceeded those boundaries. As an example of the gravity of the situation, today we are on the verge of completely eradicating polio. Now, because of these assassinations of vaccination workers, the U.N. has been forced to suspend polio eradication efforts in Pakistan. This is only one example and illustrates why, as a general principle, public health programs should not be used as cover for covert operations. What these health school deans did not say to President Obama, though they could have, is this. We've already got millions of people in

this country too paranoid to even get a flu vaccine, and now you have to go and do this? Instead of sending an undercover doctor with vaccines to find Osama bin Laden, couldn't you have sent a fake cable TV guy or someone selling encyclopedias? Here again is Times correspondent Mark Mazzetti. I should note that the White House earlier this year sent a letter to a number of health organizations saying that the CIA was no longer going to do this activity. Okay, so in addition to all the pragmatic reasons why many people don't get a flu shot, you've also got vaccine paranoia. Although, to paraphrase Joseph Heller, just

because you've got vaccine paranoia doesn't mean they aren't after you. So what's to be done about it? If we agree with medical experts that the flu vaccine is worth getting, a big if for sure, but let's make that assumption for now. What's the best way to get 100% buy-in? Here's an idea. Since you're listening to this program, you are presumably a believer in the power of data to inform decision-making, right? So why don't we start by talking straight about the danger of influenza, forcing people to stare at the data. Providing people with more science, certain people with more science, with more data, is not always the answer. And I think we need to be more creative.

That, again, is Frederick Chen, the Wake Forest economist. I think what we tell people, what kind of information we provide to people, probably makes a big difference as to how people are going to behave. But if all governments are doing every flu season is telling people, hey, it's the flu season, get a flu shot. It's the flu season, get a flu shot. I think people will tune that out fairly quickly. Indeed, there is a lot of evidence that preaching to people about the science of a given topic has almost no impact on how they make up their minds about that topic. Two political scientists, Brendan Ny science tells us it does not, and the belief that the MMR vaccine, that's measles, mumps, and rubella, causes autism, which, again, the science tells us it does not,

what these researchers find is that when people who subscribe to these myths are given scientific information to dispute the myth, they actually become even less likely to get the vaccine or to get their kids vaccinated. Maybe what we need to do isn't to go target the hardcore anti-vaccine people. Maybe what we should do is go after the people in the middle who are somewhat ambivalent. Frederick Chen, in order to find out how to go after those people in the middle, tried something that you might not think an economist would try. So it's a very simple online computer game that I created to simulate the spread of a disease

through a population. Chen admits that his virtual epidemic game is no call of duty. I would say it's not super fun, but at least it's quick and fairly painless for people to play this game. Chen recruited players with online ads that promised payouts. In terms of incentives, we said we would pay for participating in the study, and how much you get paid would depend on how you perform. The game lasts 45 days. Every day at 3 a.m. Eastern Time, you would get sent a link that tells you whether you're healthy or whether you're infected for that day.

Now, if you're infected, there's nothing you can do that day. You just have to wait till you recover. But if you're healthy that day, then you're asked to make a choice. Do you want to be safe? Do you want to take some safe action today to prevent getting infected? Or do you want to be risky? Once you make that choice, the round ends. Here's how the scoring works. So if you're healthy, you got more points. If you're infected, you got fewer points, we assume that to take precautionary measures, to take a safe action, is going to cost you some points. And there's no cost to taking the risky action. And so what happened is at the end of 45 days, we add up all the points you got throughout the game. And that's how much we paid you for participating in the experiment.

So what did Chen's game teach him about the way people think about spreading a disease like influenza? One conclusion, not surprising if you're an economist, is that the cost of taking precaution is really important. And so I think a very immediate policy implication is that we've got to find ways to make it easier, more convenient, cheaper for people to get vaccinated. If you can reduce the cost of vaccination, we should be able to increase vaccination rate. The second conclusion, which is not very surprising if you're, well, a human, is that self-interest and fear are pretty good motivators. When the prevalence of the disease is high, when the people are told that many players are infected, they tend to be safer. And when they were told that not too many people are infected,

they tend not to take the safe action. In other words, most people think about the benefits of immunization for themselves, not for the other people they might infect. Well, if people are altruistic, then we would, I think we would see more vaccinations occurring. This is the part of vaccination that probably doesn't get talked about enough. Let's imagine that you are in the prime of your life, perfectly healthy, not vulnerable in any way to dying from influenza, even if you get it. Maybe you'd miss a few days at work, but that's not that big a deal. So why do public health officials insist that you should get a flu shot? Because it's not about you.

It's about the vulnerable people, and it's about what you can do to help them. And this is what economists refer to as positive externality. Our actions benefit not only ourselves but other people, but if we're self-interested, we don't take into account the benefits we're creating for the rest of society, and we tend to do too little relative to what would be best from society's perspective. So from society's perspective, it'd probably be good for everyone to get the flu vaccine every year. Also, maybe wear a mask every day, like a lot of people

do in Asia. Well, if everybody did, that would probably cut down on the incidence of the flu. But I bet you it's going to be very difficult for this fashion to catch on because, well, it, you know, it might be a little troublesome for people to have to put on masks. And number two, it's not that good looking, right? It's, unless there's a way for people to make these masks cool and fashionable. I don't know if that's going to catch on in this country. But what if we put our best fashion designers to work making awesome masks? Why not? And you can have logos on these masks.

People, hey, actually, why not? That might be a good way to advertise. Until then, Frederick Chen thinks that we should put to use the economist's favorite tool, incentives. That doesn't necessarily mean you need to use the economist's favorite tool, incentives. That doesn't necessarily mean you need to pay people to get a vaccine, but it would help to lower the cost in any way possible. Let me give you a personal example. My employer offers free flu shots every year, and it's right here on campus. So it's very easy for me to get a flu shot. Now, the thing is, if we didn't have that program, if I had to go off campus, if I had to go to some

clinic, if I had to go to a hospital to try to get a flu shot, you know, that's more troublesome. Jeff Kwong, the Canadian epidemiologist, he also likes the incentives idea. So like a lot of healthcare workers, you know, the incentive they have is to get a chocolate bar. And that seems to work. A lot of people will go, they're just more for it for the chocolate bar. They don't mind getting vaccinated while they're getting the chocolate bar. I think one of the problems with influenza is the perception that it's not a big deal. And it's true that for most people it isn't. But they're not in the ICU seeing this previously healthy person who's ended up in the ICU,

now on a ventilator or dying from influenza. So I think that the average person on the street, they see what they see, which is their co-worker was coughing and sneezing and then gave them the infection. And, you know, I got over after just a few days, you know, why do I need a vaccine for that? But then the problem is that they could be giving it to their elderly parent or their young child or their pregnant wife who then, you know, their infant is born premature as a result of that influenza infection in the pregnant wife.

So that sort of thing, you know, plays out and it doesn't make headlines, but that's the reality that people don't appreciate. So maybe the big problem here is a branding problem. People hear flu vaccine, they think, eh, the flu, that's not such a big deal. So what if we started calling it the influenza vaccine and make some public service announcements that exploit our self-interest, our vulnerability to fear, and that leave out all the scientific preaching

and public health officials? Maybe something like this. Get an influenza vaccine today. Or you will die. Or you will kill someone else. And then you will feel like a loser for the rest of your life. Hey, podcast listeners. On the next Freakonomics Radio, there's something I've noticed on this show and elsewhere, and I'm wondering if you've noticed it too. Why do so many people, when you ask them a question, begin their response by saying this?

Yeah, that's a great question. So that's a good question. That's a very good question. So it's a great question. Is this a harmless verbal tick or a more meaningful linguistic strategy? I would be tempted to say that's a very good question that you just asked me. But because of this conversation, I'm not going to say that. Hey, thanks, Charlie.

That's next time on Freakonomics Radio. Freakonomics Radio is produced by WNYC and Dubner Productions. Our staff includes David Herman, Greg Rosalski, Caroline English, Susie Lechtenberg, and Chris Bannon, with help from Christopher Wirth. If you want more Freakonomics Radio, you can subscribe to our podcast on iTunes or go to Freakonomics.com, where you'll find lots of radio, a blog, the books, and more.