Flu Vaccine: Dishonest stat-skeptics

Well, I haven't found anyone else writing about this, probably because it's downright silly, but there's some people out there arguing that the seasonal influenza vaccine is only 1.5% effective.

Specifically, what happened is that a study published in the prestigious journal The Lancet revealed that flu shots provide only “moderate protection” against the flu, and in some seasons is altogether “reduced or absent.”

Specifically, the Lancet said the vaccine is about 59 percent effective. But when you break the numbers down statistically, what it really works out to is that the vaccine prevents flu 1.5 times out of 100.

That’s right. Using the Lancet’s own numbers, statistics show that the vaccine only works 1.5 times out of 100.

Wow.   Sounds pretty damning, and if it were actually true, I might have to rethink my position on the flu vaccine debate.  What we have here is very creative statistics.  The link they provide regarding the 1.5 times out of 100 effectiveness goes to a letter to the editor written by "J.L. Craig, BSN, PhD."  I'm fairly certain the individual in question is one Jennifer Craig, who has written several books against vaccinations and is now retired, so I haven't had much luck on a cursory search of PubMed to see what kind of research she did.  One of my favorite authors over at science-based medicine did a book review of a bunch of anti-vax books, and one of hers was critiqued (It's #6 if you care to get his impression).  She's very clearly anti-vax from her statements, and if this is the same individual then there's some clear bias going in.  That's fair, though, I have clear bias towards vaccination.  Let's look instead at the statistical ploy she uses in her letter:

... let’s examine the study to see how this spin transpired.

This was a meta analysis, meaning that the researchers used data from 28 previously published random controlled trials between 1967 and 2011. The control group, n=13,095, consisted of non-vaccinated adults who were monitored to see if they got confirmed influenza. Over 97 per cent of them did not. Only 357 got flu which means that 2.73 per cent of these adults got the flu in the first place.

The treatment group comprised adults who were vaccinated with a trivalent inactivated influenza vaccine. According to the study, 1.18 per cent got the flu.

The difference between these two groups (2.73 – 1.18) is 1.5 people out of 100. In other words, the flu vaccine did nothing for 98.5 per cent of adults in the studies.

Now in all fairness, she is technically correct.  In those studies 98.5% of people who had the flu shot were unaffected.  They were either already not going to get the flu shot or they got the flu even after having gotten the shot.  Only 1.5% of the people who got the flu shot benefited directly from it.

Does this mean that the flu shot was only 1.5% effective?  Well, no.  Let us say that, in some hypothetical world, a flu vaccine was developed that was perfect.  If you got this vaccine, you were guaranteed not to get the flu.  Not a single person got sick.  We would all agree that this shot was 100% effective.  If you got it, you wouldn't get the flu.  According to her statistical analysis and assuming the same morbidity from the study, the difference between vaccinated and unvaccinated would be (2.73-0.00) or 2.73 people out of 100.  So even with an absolutely, 100% perfect flu shot, it would still do nothing for 97.27 per cent of the population.  Does that mean the shot was only 2.73% effective?

The problem here seems to lie in the numbers.  Our puny mammalian brains have trouble comprehending numbers and making them work.  That's why it's easy for people to get confused by billions vs millions and for us to see a vaccine that cuts the number of infected people by more than half as "only 1.5% effective."  Statistics are easy to manipulate, and it's very easy to use numbers to make your case sound better.

What really gets me is Dr. Craig goes on to accuse the cdc of lying with statistics:

So where did the media get 60 per cent effective? It’s called lying with statistics. First you take the 2.73 per cent in the control group who got flu and you divide that figure into the 1.18 per cent of the treatment group who got the flu. This gives you 0.43.

You then say that 0.43 is 43 per cent of 2.73 and claim that the vaccine results in a 57 per cent decrease in flu infections. This becomes the 60 per cent effectiveness claim.

Erm, Hi.  Pot, Kettle.  Perhaps you've met?  If we really wanted to lie with statistics, we would argue that, since only 1.18% of vaccinated people get the flu, the flu shot must be 98.82% effective.  Now there's some blatant dishonesty for you.

One thing that's also difficult to work with here is that none of these studies involved working with the flu at pandemic levels.  60% efficacy only means a percentage of the population when flu levels are fairly low, but should they reach levels such as in 1918, where roughly 500 million were infected, that means 250 million people avoid the flu if they were all vaccinated.  (At the time that's roughly 30% of the population...that would mean, hopefully, that only 15% of the vaccinated population would get sick).  This is all hypothetical, of course.  More studies would be needed.  Further, the presence of protective immunity may also further reduce the number of people who get sick from the flu.  The higher the number of vaccinated people and the better the vaccine, the greater the herd immunity.  We like herd immunity, since it means the immunodeficient get some protection as well.

I will say one last thing: the mercola article is correct in pointing out that this lancet study showed zero efficacy in some seasons.  That happens.  It's always an educated guess as to which strains of influenza will hit us from year to year, and it would be unreasonably costly to vaccinate us from every flu strain we're aware of.  Even then, it might mutate into something we're entirely unprepared for.  That's part of why we will probably never beat the flu the way we beat smallpox.  I wouldn't ever argue that the flu vaccine is perfect, or even close to perfect.  The only argument I make is that it's the best defense we currently have against a virus that has a proven history of causing pandemic level infections in our population.  You may disagree, and that's fine.  I'm certain I'll get at least one comment arguing that the flu vaccine is bad or, at the very least, unnecessary, and that's fine, too.  My biggest beef is only when others take statistics that say "well, maybe it's only 60% effective instead of 78%" and instead argue that the flu shot has been proven to be pointless.  Don't do that.  It's dumb.

Further Reading:

Mark Crislip on Flu Vaccine Efficacy

WebMD Flu Vaccine FAQ

Fly Away, Katydid

Tonight I let my Katydid free.

It's been quite a while since I've written here, so unless you've spoken to me in the last few weeks, you wouldn't know about my katydid.  I sadly don't have a great picture of her, but here's the only one that had any clarity:

Yeah, the only good shot I get, and it's of her rump.

For Invertibrate Zoology, one of our requirements was to catch and take care of some kind of invertebrate and do a report on them.  For being so interested in biology, I'm fundamentally squeamish about touching living organisms, especially invertebrates (or vertebrates that potentially bite).  It's not much of an issue with cats, dogs, or other domesticated animals.  It's the wild ones.  Maybe it's a touch of respect for their wildness, maybe it's partly an ingrained fear of injury, or maybe I'm just constantly terrified that touching them will cause them harm, like with butterflies.  It's probably a combination of the three.  Whatever the cause, the squeamishness makes me hesitate when trying to grab something, making attempts at catching much of anything a bit of a challenge.  Thankfully, my roommate and my girlfriend were both happy to help.

My roommate and I caught a grasshopper and a pine beetle while we were in the mountains, helping his family.  I say "we" caught them, but really it was almost entirely his doing.  I wandered around, feeling oafish as everything with legs and wings hopped, ran, or flew away from me.  Still, we had them, and I started doing research, hoping to get the project over with as quickly as possible.  Both died in short order.  Thankfully, less than a week later my girlfriend and I stumbled upon this beautiful creature.  Since the picture of my actual caught organism is pretty weak, I include a stock footage of the species, hoping you'll understand if I argue that she looked "just like this."

Microcentrum rhombificum, or Greater Anglewing Katydids, are the only kind of katydid typically found in Denver proper, so it was fairly easy to identify her.  I'm slow to catch bugs, and generally squeamish about handling them, so I'll admit that it was my girlfriend who was daring and clever enough to catch her.  She held the katydid in her hands all the way back to the car, a fair distance since we were out for a walk.  She commented with amusement how the insect was tickling her hands as she walked.  We eventually put her in an empty qdoba bag for the ride home, and my roommate helped us transfer her from the bag to my cage.

For the next week I studied her, becoming comfortable with her general features and habits, all the while keeping her in her cage.  I delighted when she grew eggs, and fretted over her, misting her cage frequently and adding new and various vegetation for her consumption.  The project date came and my presentation was an astounding success.  Still, over all this time I never once touched or handled her. I watched her with keen interest and adoration, but not once even tried to make contact.  The cage was a barrier to both of us, and I preferred to keep it that way.

Tonight I decided to let her go.  It was time, really.  M. rhombificum adults typically only last until the end of October, so she wasn't likely going to live much longer anyways.  I walked out to my back porch, opened the cage, and set it down on the ground, away from me and towards the wilderness that is our backyard.  She didn't move.  I picked up the cage and studied her intently.  She continued to sit there, calmly grooming her legs, seemingly uninterested in the notion of freedom.  I set it down again and waited.

And waited.

And waited.


I picked up the cage again and stared in at her.  She stared right back at me.  Building up some nerve, I reached in and gently poked her wings, hoping the contact with a big, scary predator might cause her to consider making a break for it.  Of course, my own training should have told me that katydids, aka "leaf bugs", freeze when they suspect they're in trouble, what with their masterful ability to blend in with their environment.  Surprise, surprise, she froze.

Maybe a little shake of the cage might knock her out, I reasoned.  I was afraid to knock out the eggs she'd laid, so I gently yet firmly shook the cage, letting bits and pieces of weed, leaf, and romaine lettuce hearts shake out onto the backyard patio.  No katydid.  I tried again.  Still no katydid.  A third time and still no katydid, but finally I noticed that she had started crawling to the top of the cage.  I set it down again, hoping she'd crawl out, and she did.  I knew then that it wouldn't be long before she'd fly away, and I knew I had to seize the moment.  For all my squeamishness, if I didn't handle her at least a little bit before she was gone, I knew I'd regret it.

So I held out my finger to her and she climbed on.  I didn't grab her, didn't touch her in any way.  I let her touch me.  She stood on my finger, so content that when I put my finger next to a very tall weed she made no move to depart.  She sat there for a few minutes and I had my first opportunity to really examine her.  Without the mesh of the cage between us, she was a beautiful marvel of life.  I had come to appreciate her in an academic sense, but what I felt, sitting there in the middle of the night in my boxers and a t-shirt, was far greater than simple academia.  It was raw appreciation for the brilliance of the organism that sat on my finger. You can never have that same sensation in microbiology (no matter how awesome microbes are).

Moments later she flew away, vanishing into the night.  I went downstairs, sat down on my computer, and wrote this article.

I suppose there's a metaphor in there somewhere.

Those wacky creationists!

They ought to have a sitcom.  Rocky Ramsey argues:

If people die when hearts, kidneys and livers fail, then how did anyone live while those organs “evolved?” The obvious answer is that they didn’t. Man began as he is today.

This is quite possibly the most hilarious argument I've heard in years.  When you look at the phylogenetic tree just for vertebrates, you can see the slow development of the heart.  We have a lovely four chambered heart that helps keep oxygenated blood from deoxygenated blood, but amphibians with their wacky three-chambered heart like to mix them up a bit.  Then further back in time you have the fishies with their single circulation model compared to the double-circulation model the rest of us have.  You can see how each step up the ladder the heart gets more and more complex, but if you keep going back far enough, you end up with things like phylum porifora (the sponges), members of kingdom animalia in only the strictest sense, which seem to get by just fine without hearts.

If you look at kidneys and livers, you see a similar transgression as you go up the tree.  Far enough back and you have unicellular organisms that seem to live just fine without these tissues because, well, they're unicellular.  These organs are beautiful examples of how colonial life leads to enhanced survival and is favored by natural selection.  By working together, our cells can deliver vital nutrients to trillions of cells and greatly enhance the survival of the whole.  Some end up dying off, but as they're all clones of one another (hopefully), their genetic material passes on to the next generation and the genes themselves continue to survive.

The truth is the ID proponents don't really have a leg to stand on.  They argue for "microevolution" but not "macroevolution" as if the mechanisms of one do not bleed into the other.  There is no distinction between these two kinds of evolutions.  To illustrate, I found a nifty little image that I'd like to share with you.  I wish I could quote the source, but my friend who found it didn't have a direct source for it either:

Their views are often hilarious and the efforts of the misinformed, citing sources such as "Irreducable Complexity" which hardly even need to be disproved, they're so silly, or arguing about the gaps in the evolutionary record, demanding an impossible amount of data for a very simple inference (Futurama does a great job of exploring it in an episode.  Sadly I cannot find a link to the scene in question, so instead here's a general review of the episode).  Most of these ideas have been disproved or discounted, and many arguments stem from an inaccurate understanding of evolution (Crocoduck, anyone?).

These misunderstandings are hilarious, but also create a problem when those same people choose to attack evolution.  Since they don't know what evolution is, what they are attacking is not evolution, and so cannot be argued with from a logical stance regarding evolution.  Since they don't understand it, they try to make laws and regulations based on an inaccurate understanding and further their belief that they are in the right.   As I said last week, our minds aren't wired to seek out truth but to win arguments, so trying to rationally show the evidence for evolution or even explain what evolution means will fall on deaf ears.

It would be laughable if it weren't so frightening.

The unchanged mind.

Author Chris Mooney wrote an article a while back titled The Science of Why We Don't Believe Science. In it, he talks about various problems with getting the population to accept science in general. This is a clear-cut problem. The anti-vaccine movement is growing, belief in evolution is ridiculously low, and alternative medicine trends proven not to work like homeopathy continue to have millions of practitioners. Chris Mooney tries to explain why, in the fact of such evidence, people continue to believe:

The theory of motivated reasoning builds on a key insight of modern neuroscience (PDF): Reasoning is actually suffused with emotion (or what researchers often call "affect"). Not only are the two inseparable, but our positive or negative feelings about people, things, and ideas arise much more rapidly than our conscious thoughts, in a matter of milliseconds—fast enough to detect with an EEG device, but long before we're aware of it. That shouldn't be surprising: Evolution required us to react very quickly to stimuli in our environment. It's a "basic human survival skill," explains political scientist Arthur Lupia of the University of Michigan. We push threatening information away; we pull friendly information close. We apply fight-or-flight reflexes not only to predators, but to data itself.

In other words, that which is viewed as contrary to our beliefs or the patterns we feel we've witnessed are fought outright or run from more than that which coincides. If a study is posted that flies in the face of what we accept, we find ourselves more critical than studies that coincide or we ignore it outright. I know I've fallen victim to this kind of reasoning before; what I believe highly influences what I'm inclined to accept at face value. Some of this stems from my religious upbringing, some of it from my nature. Now that I strive the follow the road of the skeptic, I fall victim to it, too. I know this and try to work on it.

What this really means, though, is that the more certain we are that we are right, the more difficult it is to change our minds. Anyone who's tried to get into a legitimate debate with someone idealistically opposed will find that it's nigh impossible to truly change minds. The act of altering one's opinion is a lengthy process and a single discussion will not sway minds. It's why as a general rule I avoid debating with the most passionate; they are good arguers, and have at the forefront of their mind arguments that I would need to sit down and contemplate before rebutting. It's easy to see what we want to believe and ignore that which we don't, whether we be scientists or lay people.

Looking at all of this, I've come to a broad conclusion: I cannot legitimately discuss a point with someone who claims to have never changed their mind. It doesn't have to be about faith.  They could even eventually swing back to original ideas. The more firm and unyielding we become, the less often we are to admit our own foolishness.  I feel uncomfortable around anyone who speaks so brazenly that they cannot admit that they're wrong, and when that feeling is directed at me, the unease explodes to new levels.

This isn't to say that we don't know anything, or that we are more often wrong than we are right.  What it does say is that we need to be aware of our tendency to cherry-pick data and information, and we need to constantly seek out criticism of our ideas to see how well they withstand open critique.  I suspect many look at this as further evidence that science is flawed, that we don't know what we're talking about, and that we shouldn't knock homeopathy or blatantly accept evolution because science "requires as much faith" or "means we're probably just looking for studies that confirm what we believe".  The difference is in the scientific method, in our efforts to continually refine ideas and eliminate bias as much as is possible.  Forged results like the Andrew Wakefield study eventually get rooted out, because there will eventually be enough data that the more fallacious results will not withstand the test of time.  Certainly immediate studies and opinions may turn out to be wrong, but in the broad history of science, the truth tends to win in the end.

And maybe it doesn't.  Maybe tomorrow I'll find something that tells me I'm absolutely, completely wrong in my assumptions about science.  I don't think so, and as I grow older and wiser things seem to more elegantly coincide in support of science and away from my meager, small-minded instincts.  As Tim Minchin says in his song Storm

If you show me/ That, say, homeopathy works,/ Then I will change my mind/ I’ll spin on a fucking dime/ I’ll be embarrassed as hell,/ But I will run through the streets yelling/ It’s a miracle! Take physics and bin it!