Updated: January 17, 2010

Swine Flu Pandemic
Communication Update

Pandemic Interruptus: It Ain’t Over Till It’s Over

What should pandemic risk communicators be saying in January 2010, when swine flu looks to non-experts like it’s disappearing, when swine flu vaccine is a drug on the market, and when swine flu news has taken on a distinctly skeptical tone?

It has been a wild ride so far, from high drama to bored skepticism in a mere nine months. The novel H1N1 influenza virus was first identified in samples from two U.S. children in mid-April 2009, and then a week later in samples from Mexico. April is a month when there’s normally very little flu in the northern hemisphere. From April through December, the U.S. had more flu than in the average flu season. In most of the country, but not all, we saw a first wave in the spring, then a summer decline (but still much more flu than usual in summer), and then a bigger second wave in the fall. Then the fall wave plummeted.

By mid-January in most years, seasonal flu numbers are increasing in the U.S. But in this pandemic year, the pandemic flu numbers are decreasing, and there is virtually no seasonal flu around yet. The same thing is happening in most of Europe. Pandemic H1N1 is way down, and except for a few isolated cases seasonal flu has yet to appear.

Naturally the media have virtually decreed the pandemic over. And some commentators have said, in hindsight, that it wasn’t a pandemic at all.

In the ecosystem of public opinion, all niches are filled. At one extreme are those who confidently predicted a rerun of 1918 or worse, some of whom even now maintain that it happened and health officials somehow managed to cover it up. At the other extreme are those like Marc Siegel and Michael Fumento who were pandemic scoffers from the outset and are now crowing that they were right all along.

Many in the media have happily oscillated from one extreme to the other. Some of the newspapers and broadcast stations that headlined the direst predictions now headline preposterous charges that it was a “false pandemic” manufactured by a conspiracy of public health officials and pharmaceutical companies.

Okay, so what should pandemic risk communicators be saying?

1. We don’t know what’s coming next.

Although people with normal interests may think of flu as ordinary and boring, public health experts see influenza as endlessly surprising, among the most fascinating of diseases. And influenza is never more surprising than when a new flu virus emerges and launches a pandemic.

Experts see flu as unusually unpredictable – but considerable unpredictability is a hallmark of nearly all crisis situations. That’s why acknowledging uncertainty is a core principle of crisis communication.

The only sensible way to plan pandemic response – and the only sensible way to talk about pandemic planning – is probabilistically. We don’t know what’s next, but we can estimate probabilities and act accordingly.

Probabilistic thinking is the very essence of risk assessment and therefore of risk management. And probabilistic language is an essential part of risk communication.

Thinking and talking probabilistically about risk requires asking six core questions:

• What outcomes are possible?
• What is the estimated probability of each possible outcome? (No one can really know, but experts can make informed guesses.)
• What are the predicted effects of each possible outcome, and how bad is each set of effects? (This can be modeled.)
• What can be done, at what cost, to mitigate each set of effects? (This can be modeled too.)
• How confident are we about the answers to these questions? (Not very.) What are we likeliest to be wrong about? In which direction?
• Based on all of that, what does it make sense to do? (This will be a debatable judgment based partly on values and partly on the guesses and modeling above.)

It doesn’t follow that the wisest course of action is to prepare only for the likeliest set of outcomes. Dire outcomes justify preparedness (if preparedness is possible and cost-effective) even if they’re pretty unlikely. That’s why people buy fire insurance for their homes – not because a big fire is the likeliest outcome, but because it’s a very bad outcome that isn’t vanishingly unlikely.

Inevitably, then, a lot of preparedness will turn out unnecessary or excessive. When your home doesn’t burn down, you don’t cancel your insurance, nor are you angry that you wasted your premium. You’re glad your home didn’t burn down last year, and also glad you’re insured in case it burns down this year.

And fire insurance salespeople don’t claim that their prospective customers’ homes are going to burn down. They ground their sales pitch not in the probability of such a disaster, but in its magnitude. They’re selling a hedge to lessen the impact of a profoundly undesirable scenario – one that is pretty unlikely, but not so unlikely as to constitute a negligible risk. And they’re selling the peace of mind that comes with knowing you have hedged against such a possible disaster.

What’s missing from most people’s pandemic thinking is this probabilistic mindset.

Sports fans think probabilistically. Baseball fans, for example, know that there are times when the smartest thing for a batter to do is try to bunt the runner into scoring position. If the strategy doesn’t pan out, a commentator may remark that the batter probably wishes in hindsight that he’d swung for the fences … but nobody says he should have done so when the odds said bunting was the right bet. There are obvious analogues in virtually every sport: The right play remains the right play even when it didn’t work this time.

Similarly, we all understand that weather forecasters play the odds, and advise us to play the odds. When there’s a 70 percent chance of rain we take an umbrella to work and cancel our picnic plans – and we’re not especially outraged if the sun shines all day. When there’s even a 20 percent chance of a hurricane we buy extra food and check the flashlight batteries – and we feel neither foolish nor victimized if the hurricane weakens or changes course.

But in public health, non-experts often indulge in outcome-biased thinking instead of probabilistic thinking. Thus many people – and many journalists and politicians – seem to believe that officials should have prepared for exactly the pandemic we got (so far), no more, no less … as if they could have known in advance what sort of pandemic would come along.

If the 2009 pandemic had turned out as severe as it looked last April in Mexico, Congress would long since have launched investigations into why the CDC was insufficiently prepared, why we let our public health infrastructure decay, etc. If we end up with a severe third wave, those same questions will be asked. Even the mild pandemic we have had so far was sufficient for “tough questions” about the slow pace of vaccine production. But since the pandemic looks like it’s over (for now) and since it wasn’t very bad (for most people), many are asking instead why public health officials scared us unnecessarily.

I’m not going to burden readers with endless quotations from commentators and critics in the U.S., Europe, India, and elsewhere. They’re all grounded in the same false reasoning:

1. Officials warned us that things might get really bad, and urged us to take precautions.
2. Things didn’t get that bad (at least not yet). Those who took precautions feel foolish. Those who didn’t take precautions feel vindicated.
3. Officials must have known that things wouldn’t get that bad. They misled us on purpose. Here’s why they did it….

Outcome-biased thinking isn’t confined to public health. Consider three other examples.

• After hurricane Katrina, most people came to believe in hindsight that the government should have done more to enable the New Orleans system of levees to withstand heavy floods in a strong hurricane. They didn’t think so beforehand, and they still don’t want to retrofit other cities against other catastrophes. There’s not much demand to prepare New York City for a tsunami or the New Madrid Fault region for an earthquake. Just New Orleans for a hurricane.
• After the financial system imploded in 2008-2009, just about everyone agreed that there should have been tougher regulation of credit default swaps, securitized mortgages, and whatever else needed regulating in order to keep the economy on track. Not that we wanted more government regulation at the time. Nor do we want more government regulation now … except for regulating whatever caused the economy to tank last year.
• After the Christmas Day bomb attempt on Northwest Airlines Flight 253, a near-consensus emerged that the government should have seen it coming and stopped Umar Farouk Abdulmutallab from getting onto the plane. Does that mean we want all people put on the no-fly list if they’re from countries with significant Muslim populations and their fathers think they’re too radical? Nope – just Abdulmutallab and everyone else who’s going to try to blow up a plane.

I’m not asserting that it’s a bad idea to spend more money preparing urban areas for natural disasters, or to regulate financial institutions and especially innovative financial instruments more strictly, or to be more rigorous in the screening of international air travelers. There are pros and cons to each of these measures. And there are counterexamples – horror stories of money spent preparing for natural disasters that never came, of industries that seem unable to compete and innovate effectively because of over-regulation, of innocent people who have struggled unsuccessfully to persuade officials to take them off the no-fly list.

My point is that you can’t prepare only for a hurricane in New Orleans, regulate only the industries that are about to implode, and keep only the actual terrorists from flying. And you can’t get people all worked up about only the pandemics that are going to turn out to have been severe.

You can be as risk-averse or as risk-tolerant as you want in how you play the odds. But you can’t avoid playing the odds.

In all these examples where post-hoc outcome-biased thinking prevailed over real-time probabilistic thinking, the situation was scary enough that many people felt powerless and vulnerable. Sometimes a degree of psychological regression happens when people feel powerless and vulnerable. We get childish and petulant. Like children, we want mommy and daddy to make it right.

So if something bad happens, we complain bitterly that mommy and daddy should have protected us better. And if something bad doesn’t happen, we complain nearly as bitterly that mommy and daddy shouldn’t have disrupted our playtime with unnecessary warnings and precautions.

These examples have something else in common. Discussions of sports and weather refer constantly to playing the odds – but discussions of emergency preparedness, government regulation, counterterrorism, and pandemic response do not.

Early on in the pandemic, public health officials should have been saying – again and again – something like this:

We don’t know how severe this pandemic is going to be. Yet we have to make decisions now – for example, decisions about how much vaccine to order, and decisions about whether to advise closing schools and canceling public events. So some of these decisions may end up wrong. We are trying to err on the alarming side. We’d rather prepare too much than too little. But if things get very bad, critics will say that we should have done more – and in hindsight they will be right. And if the pandemic turns out mild, critics will say that we should have done less – and in hindsight they will be right too.

Officials did say things like this from time to time. At the very start of the CDC’s second pandemic press briefing on April 24, Richard Besser (then acting director) put it superbly:

First I want to recognize that people are concerned about this situation. We hear from the public and from others about their concern, and we are worried, as well. Our concern has grown since yesterday in light of what we’ve learned since then.

I want to acknowledge the importance of uncertainty. At the early stages of an outbreak, there’s much uncertainty, and probably more than everyone would like. Our guidelines and advice our [are] likely to be interim and fluid, subject to change as we learn more….

We do not know whether this swine flu virus or some other influenza virus will lead to the next pandemic; however, scientists around the world continue to monitor the virus and take its threat seriously.

Media coverage of the Besser press briefing was substantial, but very few stories quoted this passage. Reporters went for the hard news: what the CDC thought was happening and what it was going to do about it. “Uncertainty claims” – explicit statements that the situation is uncertain, that officials are playing the odds, and that in hindsight their response may turn out too aggressive or not aggressive enough – are hard to get into the media. Officials almost always end up sounding more certain in news stories than they sounded during the news conference or the interview.

Later on, commentators who missed the qualifiers and uncertainty claims write, “Remember when they said we were all gonna die?”

Even if uncertainty claims make it into the media, they are hard to get into people’s heads – especially the heads of people who feel powerless and vulnerable, who want officials to be confident and definite.

And of course most officials are less committed than Dr. Besser was to communicating their uncertainty. Especially in crisis situations, it’s awfully tempting to project certainty instead (as if that were a stand-in for competence) – to give the anxious public what it seems to want.

But nothing is more important in pandemic risk communication than persuading the public (and the politicians) to think probabilistically. Public health officials need to insist on their uncertainty; they need to make uncertainty the message, not the preamble to the message.

Uncertainty about the future should have been stressed, over and over, early on in the pandemic – far more than it was. But maybe we’re still “early on” in the pandemic. As Yogi Berra (a probabilistic thinker) taught us, it ain’t over till it’s over. So probabilistic thinking should be stressed now as well – both about the decisions that have been made up till now, and about the decisions we face today.

As the 1957 Asian Flu pandemic was looming from a distance, the U.S. Surgeon General at the time, Leroy Burney, said:

I am sure that what any of us do, we will be criticized either for doing too much or for doing too little…. If an epidemic does not occur, we will be glad. If it does, then I hope we can say… that we have done everything and made every preparation possible to do the best job within the limits of available scientific knowledge and administrative procedure.

I doubt that it’s ever advisable to make “every preparation possible.” But Burney’s first sentence is right on target.

Uncertainty is Message #1.

2. It’s a real pandemic.

After many weeks of information-gathering, discussions with Member States, and expert debate, the World Health Organization (WHO) declared the swine flu outbreak a pandemic on June 11, 2009. In January 2010, some commentators are trying to “undeclare” it.

They’re wrong. It’s a real pandemic.

Like a lot of terms in public health, the word “pandemic” isn’t rigorously defined. But there is general agreement that an influenza pandemic has three defining characteristics.

Experts continue to debate the close cases. The Russian Flu of 1977 is a good example. It was caused by the re-emergence (probably from a lab) of a 1950 strain of human H1N1, and it quickly spread globally. But it mostly affected people younger than age 23 – people who hadn’t been around when that strain was circulating previously. And it did not cause excess mortality in any age group. A few experts consider the Russian Flu to have been a pandemic, but most do not.

In 1995, influenza expert Edwin D. Kilbourne said that “defining a pandemic is a little like defining pornography – we all ‘know it when we see it,’ but the boundaries are a little blurred.” Dr. Kilbourne’s wonderfully readable article discusses several examples of such blurriness, especially regarding the concept of a “novel” virus.

If worldwide disease surveillance had been good enough in 1977 to identify the Russian Flu outbreak at its inception, it might have been declared a pandemic – and then “undeclared” when more was known. But it would take a very fringe expert indeed to recommend “undeclaring” the H1N1 pandemic of 2009.

3. It’s a mild pandemic, at least so far.

Sometimes it seems like the world (the world of people interested in flu, at least) is divided into two camps: the people who think swine flu is too mild to call it a pandemic versus the people who think it’s a pandemic and how dare anyone call it mild!

I’m in the third camp, which feels like the smallest camp: the people who keep insisting that it’s a mild pandemic so far.

It’s certainly not – so far – the pandemic that health officials were expecting and dreading. That expectation was shaped by two anchoring frames.

The first standard of comparison is the pandemic of 1918, the most severe pandemic of modern times. The 1918 pandemic is estimated to have killed about 675,000 Americans – virtually all within a single year, though the pandemic actually lasted 27 months. Its case fatality rate in the U.S. was roughly 2% – compared to roughly 0.02% for the 2009 pandemic so far, about a hundred times lower.

The second standard of comparison is the incredibly deadly novel H5N1 (“bird flu”) virus that emerged in 1997. Bird flu has not gone pandemic (so far); it has infected fewer than a thousand people worldwide. But it killed nearly 60 percent of them – a case fatality rate 30 times worse than the 1918 pandemic, and 3,000 times worse than the 2009 pandemic so far. The nightmare that influenza experts have been living with since 1997, and are still living with today, is that bird flu will mutate in a way that makes it as transmissible as ordinary flu (or as swine flu), only thousands of times deadlier.

Flu experts prepared for the 2009 pandemic in the shadows of 1918 and bird flu. They shied away from the most horrific possibilities, but they never even considered the mildest possibilities.

U.S. experts, for example, developed a Pandemic Severity Index (PSI) that had five categories. The PSI assumed that a pandemic would infect about 30 percent of the U.S. population. A Category 1 pandemic would have a case fatality rate of less than 0.1%, adding no more than 90,000 U.S. fatalities – still more than twice as bad as the average flu season. A Category 5 pandemic would have a case fatality rate of greater than 2 percent, meaning more than 1,800,000 U.S. fatalities – basically a rerun of 1918 or worse, with a much larger population. A bird flu pandemic would be off the scale in one direction. The swine flu pandemic we got is off the scale in the other direction … which may be why officials haven’t mentioned their PSI in quite some time.

I have been describing the swine flu pandemic as “mild” since before it was declared a pandemic – almost always adding the crucial qualifier: “so far.” I based my use of the word “mild” on evolving published data about this pandemic, compared to prior pandemics and average flu seasons, not on my own non-existent influenza expertise. On May 6, I wrote: “Swine flu looks to be an extremely mild pandemic if it goes pandemic at all, despite WHO warnings that it may ‘come back with a vengeance’ in the fall.” On June 4, I wrote that it was “still mild.” On June 17, I wrote: “The big public health risk isn’t the relatively mild flu that’s circulating now…. Swine flu could come roaring back in a much more virulent second wave.” On July 21, I proposed three core pandemic messages. One was: “Pandemic H1N1 looks very mild so far.” Another was: “We must prepare for the possibility that pandemic H1N1 could become more severe.”

I kept arguing that a communicator who failed to acknowledge the current mildness of the pandemic could not credibly warn about its possible future severity.

Finally, on December 2, I entitled my Swine Flu Pandemic Communication Update: “It’s Official (sort of): The Swine Flu Pandemic Is Mild So Far.” The CDC’s own data showed the mildness of the pandemic, I said, and the CDC was unwisely refusing to say so.

This time I was criticized for insisting so aggressively on the pandemic’s mildness. (See my December 15 acknowledgment of this criticism.) I understand some of the reasons why the term “mild” strikes many as offensive:

• It is insensitive to the impact of the pandemic on those who lost a loved one to H1N1, or were severely ill, or even just worked 90-hour week after 90-hour week in a local health department.
• It ignores the reality that the pandemic has already killed several times as many children as the average flu season. (The average flu season kills mostly the elderly.) That’s a fact that has understandably and justifiably worried many parents, and left them feeling that the pandemic was anything but mild.
• It also ignores the reality that many more people under 65 were hospitalized and in intensive care units during the 2009 pandemic than during the average flu season. Often concentrated over a short period of time in specific “hot spots” around the country, these hospitalizations constituted an unusual burden on the U.S. medical system.
• It focuses on one aspect of pandemic severity, the number of deaths. But pervasiveness matters too. My college professor daughter, for example, says more of her students were out sick with the flu last fall than any semester in her memory. As far as she knows, none of them died. But she certainly experienced the fall as a severe flu season.

Despite all of that, the fact remains that in terms of overall mortality the 2009 pandemic has been very mild so far – so mild that some are denying that it’s a pandemic at all. The time has come for officials to acknowledge and insist on the middle ground. Yes, it’s a pandemic – so far a mild one overall, albeit tragic for tens of thousands of people around the world.

In fact, official acknowledgment of the pandemic’s mildness is long overdue. Both the CDC and the World Health Organization have steadfastly avoided the word “mild” in their pandemic communications. Both have passed up many chances to breathe an audible sigh of relief: when the alarming initial news from Mexico was not borne out, when the pandemic case fatality rate came in lower than the rate of prior pandemics and lower than the rate of the average flu season, etc. Both have seldom said publicly what I think they must be saying privately: “So far, so good. We’re not out of the woods yet, and the pandemic could still take a turn for the worse, but to date it has been much less devastating than we dared hope.”

In part because of their failure to acknowledge the pandemic’s mildness, officials are now reaping the whirlwind. Millions of ordinary citizens have seen for themselves that (with tragic exceptions) this pandemic is not such a big deal. If the CDC and WHO think otherwise, if what we have experienced over the past nine months is really the sort of pandemic health officials consider serious, then it makes sense to shrug off their pandemic warnings altogether.

Officials’ failure to acknowledge that the pandemic has been mild so far thus justifies public skepticism about officials’ warnings that this pandemic or some future pandemic could be far more severe. It even gives a semblance of credence to the absurd allegation that officials have been promoting a fake pandemic for ulterior purposes.

It’s a real pandemic, but so far a mild one. Officials need to say so.

4. It’s probably not over – but we don’t know what’s coming next.

I’m not a virologist, and I’m not entitled to an opinion about where the 2009 pandemic is headed in 2010. In fact, many virologists think they’re not entitled to an opinion either. They say it’s anybody’s guess.

The least likely possibility, I’m told, is that swine flu will simply disappear. Influenza is such an unpredictable disease that the experts aren’t ruling anything out, not even that. But the H1N1 virus transmits easily from person to person. And it has lots of people left to infect – people who have neither had the disease nor been vaccinated against it. So most experts expect to see more swine flu.

One question is when swine flu will surge again in the U.S. (It hasn’t disappeared. It is still circulating in low levels here, and at higher levels in some countries around the world.) There are three main possibilities:

A more important question than when swine flu will resurge is how the novel H1N1 virus might change along the way. The scariest possibility is that it could become more virulent, mutating in a way that makes it much less mild. One nightmare scenario: Swine flu and bird flu mix-and-match genetic material, producing a new virus as infectious as swine flu and as deadly as bird flu.

All changes are possible. The swine flu virus could become more or less virulent. It could become more or less infectious. It could attack different age groups or people with different medical conditions. It could become resistant to antiviral drugs. It could (and almost certainly will, over time) drift genetically so the existing vaccine no longer works very well.

Or, of course, it could stay pretty much the way it is – with more and more people becoming immune to it as a result of previous exposure or vaccination. Influenza strains mutate incessantly, so “staying the same” is considered a pretty unlikely scenario. But as the experts all say, the only thing you can be sure of with influenza is that it will surprise you. Staying the same is one possible surprise.

And here’s yet another question: What’s going to happen to the seasonal flu strains? Precedent says one or both of the currently circulating influenza A strains will probably disappear, supplanted by the new flu in town. But that’s not guaranteed either.

If the U.S. is going to have its usual flu season this winter, it’s already a little late … but not yet ridiculously late. So:

• Maybe we’ll see no more pandemic flu this winter, but the seasonal flu will come back as usual.
• Maybe we’ll have to endure both simultaneously – a pandemic third wave plus the usual flu season.
• Maybe the previous seasonal influenza A strains will disappear for good, and swine flu will be our new seasonal influenza A until the next pandemic.

If swine flu does supplant the earlier seasonal A strains (whether it happens this winter or a year or two from now), that could be very good news, especially for seniors. In recent years seasonal influenza has been made up of two influenza A strains: H3N2 (still circulating since it caused the 1968 pandemic) and the 1977 version of H1N1. (There are also two kinds of influenza B in circulation. Influenza B doesn’t seem to compete with influenza A strains, and isn’t known to cause pandemics.) H3N2 is currently the deadlier of the two A strains, especially to the elderly. If H3N2 gets wiped out, and if pandemic H1N1 becomes seasonal and stays as mild as it is so far, we’re unlikely to reach our annual average of 36,000 U.S. flu deaths in the coming years.

In other words, by out-competing and replacing the deadlier seasonal strains (especially H3N2), the 2009 pandemic could end up saving lives!

Like everything else about influenza, this isn’t guaranteed either. Maybe swine flu will end up coexisting with one or both of the two seasonal influenza A strains that have been circulating since 1968 and 1977. Maybe it will supplant those earlier strains but become deadlier itself (just as H3N2 is deadlier today than it was during the pandemic of 1968).

Or maybe swine flu will disappear after all, leaving us back where we started.

Key Messages

So what are the key messages of the moment about the swine flu pandemic? I think there are four.

Copyright © 2010 by Peter M. Sandman