While the journey and research into H1N1 has been quite interesting for me, it’s time for me to move on from this topic and get back to my real life (Happy birthday honey! You get your wife back!). So I thought I’d leave you with a few final thoughts I have about swine flu.

Analogies

One of the main ways both the public and the media have tried to make sense of swine flu is through analogies, or comparisons. We’ve got H1N1 compared to seasonal flu; swine flu 2009 to swine flu 1976 (or 1957 or 1918). We’ve got H1N1 media hype compared to the hype around other illnesses such as Avian Flu or SARS. We’ve got child deaths from H1N1 compared to child deaths from seasonal flu, or cancer, or car accidents, or malaria. Use the right analogy and you can spin the risks of H1N1 anyways you like!

When reading such comparisons, my advice is to do your best to think about how the analogy works (how are the things being compared similar?) and how is does not (how are they different?). For example, perhaps the most common comparison is between H1N1 and seasonal flu. H1N1 has killed just over 1000 in the US, whereas seasonal flu kills 36,000. So why all the fuss about H1N1? Well, let’s note the ways in which the analogy works—were talking about flus, and the same country, and deaths;  so far, so good. How does it not work? H1N1 death totals are lab-confirmed; seasonal flu totals are estimates. H1N1 death distribution is very different than seasonal flu; for some groups, like children, there have in fact been more deaths from H1N1 than seasonal flu (171 (probably 199) vs. 82), and we’re not done the flu season yet. I’m not saying, “Panic! H1N1 is a huge risk and we’re all gonna die!” But I am saying that the dismissive “it’s milder than seasonal flu” misses some details that may be relevant in assessing your family’s risk from this illness.

Another common comparison is child deaths from H1N1 vs. child deaths from other causes, like car accidents, cancer, or malaria. This analogy is helpful in keeping the overall risks of flu in perspective, but it can also be used in misleading ways. More children die of car accidents than drowning each year in Canada, but that doesn’t make the deaths from drowning any less tragic nor the desire to prevent them any less real. Perhaps a stronger analogy would be to compare pediatric flu deaths to deaths from other vaccine-preventable diseases.  Almost 200 children in the US have died from H1N1—far less than die in car accidents, to be sure—but when was the last time we heard of that many kids dying of a vaccine-preventable illness in a first world country? If these deaths were due to measles, or polio, or diphtheria—something other than “just a flu”, a disease most of us have had and survived--would our assessment of risk or mildness of the illness be different?

Or the 1976 GBS fiasco after the swine flu shot. Yes, it is absolutely true that in 1976 “the risks of the vaccine outweighed the risks of the illness”: only ONE person died of swine flu that year. But it’s not 1976 anymore. How do these risks play out using 2009’s death totals? And the comparison to 1918 cannot be properly made without thinking about all the ways in which our world is not as it was then: antivirals, antibiotics, universal health care or better access to medicine, not on the heels of a world war, better and more accurate testing techniques, ventilators, etc.  It’s clear the 2009 pandemic is not going to be a repeat of the 1918 Spanish Flu; of course, its also clear that the if 1918 Spanish flu hit in 2009 it would be nowhere near as devastating (though I think it would still be far more devastating than today’s swine flu).

My point is, I think there is a reasonable and rational middle ground to be had in assessing one’s risks from H1N1 between panic on the one side, and dismissal on the other. And these risks are not the same for everyone.

I can understand why some folks choose not to get vaccinated: the number of tests/studies for safety and effectiveness of the H1N1 vaccine are few; all vaccines have side effects, some serious; no vaccine is 100% effective; it is possible that serious side effects of vaccination are under-reported, and that new side effects or illnesses will be shown to be connected to vaccines in some way; and the risk of serious complications from H1N1 is not the same for everyone. This does not make these folks who choose not to vaccinate irrational or blindly following the word of conspiracy theorists or bad science. (Though some who choose not to vaccinate undoubtedly are!)

I can also understand why some folks choose to vaccinate. They may be in a group that is at higher risk for serious H1N1 complications or death (e.g., asthmatic); they may have read the research on vaccines and know that while there are occasional side effects, some severe, the known risks of illnesses generally outweigh the known risks of vaccines; and most vaccines work well at preventing illness in most people most of the time. This does not make these folks unthinking, blind followers of "the government" and "Big Pharma". (Though some who choose to vaccinate undoubtedly are!)

For those wanting to keep current on H1N1 developments, I highly recommend the European Centre for Disease Prevention and Control’s H1N1 page. They post daily and weekly updates, and these updates have data from around the world, and links to recent studies, news stories, etc. The most recent update, for example, has info about the mutated strains of H1N1 in Norway, the Tamiflu-resistant strains in the US and Wales, as well as preliminary safety data about the vaccines. What I find most admirable about this site is that they by and large separate fact from spin (for example, while they acknowledge the fact about the mutations, they say explicitly that it is too soon to draw any conclusions about the significance); they give references to papers that contradict each other in their findings, and they report negative events (e.g., GBS and foetal deaths post-vaccine) as well as positive. They are a great source of information in and of themselves, as well as providing links to all kinds of starting points for further research.

Thanks for all your kind comments, as well as those who have challenged what I have written—there are still more questions than answers about H1N1. Stay well.  Now, back to our usual family life programming…

After noticing a rate of severe allergic reactions higher than expected (1 in 20,000 vaccinations rather than the expected 1 in 100,000 vaccinations) GSK has asked provincial governments using vaccine from one particular lot shipment to stop using it. I am pleased to see the company taking this seriously and monitoring for statistically anomalies post-vaccination. Details here. See also here.

An interesting study was released today, looking at 58 children admitted to Toronto’s Sick Kids Hospital between May and July 2009 with severe H1N1, compared with 200 kids admitted for seasonal flu between 2004 and 2009. Details in this article here. Here’s the things that stood out to me:

Every year, Sick Kids admits about 40 children with seasonal flu. With 58 admitted for H1N1 to the end of July, this number will be far higher this year with H1N1, as the second wave numbers (ongoing right now) which are higher than July’s are not included.

22% of kids admitted with H1N1 had asthma, whereas only 6% of kids admitted with seasonal flu had asthma.

Almost half of all ICU admissions at Sick Kids for kids with H1N1 were kids with asthma, and it didn’t matter how severe the asthma was. Even children who only occasionally needed to use their puffers were among the admitted.

There were no deaths among the 58 H1N1 kids, and 1 death among the 200 children admitted with seasonal flu. So while asthmatic children are admitted more often, they also recover more easily than do more elderly folks with underlying conditions like asthma once medical care is received.

Interesting piece in the National Post today, very much along the lines of what I have been advocating and trying to do on this blog. It’s from Joe Schwarz, and titled “An Injection of H1N1 Reason.” You can read his op ed piece here, and below I’ve included my response. 

Excellent post! I have been blogging on this very topic, and there's a few things I have to add.

1- When reading anti-vac folks (or anyone else), I recommend you click on links provided or look up studies referenced. By doing so and reading original sources I have found (a) studies claiming to show flu vaccines ineffective in children, in which the authors of the study state explicitly that vaccines have high efficacy in children, and good safety; (b) claims that H1N1 is no big deal--no worse than seasonal flu for kids--as last years' flu season in the US claimed 115 children, yet no mention is made of the fact that "last year's flu season" means data up to the end of August, hence 43 pediatric deaths from H1n1 itself from Apr-Aug are included among the 115, which is why the number is so high compared to previous years; (c) on a list of different years and child flu deaths, only certain years had data added as to vaccination rate, making it look both like vaccination rate was higher than usual and hence that flu vaccine causes death, yet when I read the original source the explicit statement "vaccine rates were similar to those of previous years" was found. And my favourite? The footnote provided supposedly showing the poor success rate of flu vaccine for children in fact took me to site with a request for children to participate in a study, which, clicking further, I discovered was still on-going and they needed no further participants. The lesson?--Putting in references and footnotes makes a point of view look reasonable, and very few folks actually follow up these sources and see if what has been quoted is accurate or in keeping with the original source. Do it!

2 - Another source you and some of your readers may enjoy is the ECDC (The European Centre for Disease Control and Prevention). They post a daily H1N1 update with a world perspective, and I particularly like them as they do not just give hard data (numbers). They also provide links to recent studies of relevance to H1N1--including those that contradict each other--new recommendations from WHO and elsewhere. Just today there is a link to a study from Melbourne Australia following 112 H1N1 patients at adult hospitals during their winter flu season, the largest retrospective study to date.

3 - Vitamin D is a very promising line of study, but even its main proponent (Dr. John Cannell) does not make the claims about it or H1N1 shots I have seen on anti-vac sites. Google "Vitamin D Council May 2009 Newsletter" for Cannell's thoughts on Vit D (helpful, but not a panacea), H1N1 shots (plans to get one) and Guillain-Barre (risks overstated).

Despite appearances on comment boards and such, there is a very significant population of Canada (and the world) trying to find accurate information about H1N1, and who are happy to read both sides, check facts and references for themselves, and make up their own minds. Keep up the good work!

I’ve been asked this question a lot. Here is what Andre Picard, health reporter for Canada’s Globe and Mail newspaper, had to say in his column The Daily H1N1 Question.

Tuesday, Nov. 10

Today, we a number of related questions:

Q: Is it true that I can’t sue if the swine flu vaccine makes me sick or kills me?

Q: I’ve read some pretty frightening things about vaccines on the Internet. How many people do they actually kill?

Q: I read that in the U.S. vaccine makers can’t be sued. Is that true in Canada too?

Q: Why have the vaccine producers been given blanket immunity shielding them from any adverse reaction lawsuits?

Q: When I got the H1N1 vaccine, I had to sign a waiver that said I couldn’t sue. Is that valid?

A: In the U.S., federal legislation has, since the 1980s, protected vaccine makers against lawsuits related to childhood vaccines. In July, that protection was extended to makers of H1N1 vaccine. This was done because, in the litigious U.S., drug companies had essentially threatened to stop producing childhood vaccines, which are not particularly profitable and there were fears that production of the flu vaccine would be delayed by legal concerns.

The inability to sue manufacturers does not mean those who are vaccine-damaged cannot receive compensation. The U.S. has a “vaccine court” that hears cases and awards compensation.

In Canada, vaccine manufacturers do not have blanket protection from lawsuits and suits related to harm caused by vaccine are usually settled out-of-court. One province, Quebec, has a no-fault insurance program that operates in a manner similar to the U.S. vaccine court. Over two decades, there have been about 100 claims and a couple of dozen substantial awards.

The Canadian Paediatric Society estimates that about five children a year will potentially suffer a serious adverse event from vaccination. Bear in mind that there are almost 400,000 children born a year and they get approximately two dozen shots by the time they hit kindergarten.

Health officials describe the number of severe adverse reactions to influenza vaccines as “very rare.” The biggest danger is a life-threatening allergic reaction to a component of the vaccine such as egg proteins. In rare instances – again, numbers are hard to come by – a person can suffer from Guillain-Barré syndrome after vaccination. The autoimmune condition, which is characterized by paralysis that can be reversed, is related to fever. The disastrous 1976 swine flu vaccination campaign was derailed by reports of numerous cases of Guillain-Barré. But infectious disease experts note that the flu itself triggers far more cases of Guillain-Barré than the vaccine.

On the question of “immunity” from H1N1 vaccine lawsuits (a clever play on words), the reality is a bit more complex. In the contract between the government of Canada and GlaxoSmithKline, Ottawa promises to “indemnify” anyone harmed by the vaccine. Practically, what this means is that, if you suffer harm from the vaccine, you can sue and the government, not GSK, will be responsible for paying the settlement.

Many have argued that this is an unnecessary gift to a big, wealthy pharmaceutical company. But the underlying philosophy – as articulated in a landmark 1985 Supreme Court judgment - is that people exposed to a potential harm while undergoing an intervention that is in the greater public good, particularly at the urging of the state, should be compensated by the state if they are harmed in the process.

Finally, when you get a H1N1 vaccine you will be asked to sign a waiver. The wording of these waivers varies a lot across the country but most say that you waive the right to sue those administering the vaccine – principally nurses. Lawyers consulted said that these waivers would in no way limit your ability to sue the vaccine maker of the government.

I’m puzzling over the status of H1N1 here in Alberta. We’re clearly in the “second wave” here, with sharp rises in hospitalizations, ICU admissions and deaths in the past 2 weeks or so. The current lab-confirmed stats for Alberta say there have been 25 H1N1 deaths here (as of November 9):

http://www.health.alberta.ca/health-info/influenza-H1N1-cases.html

On the one hand, given the many media sources saying “Canada has 2000-4000 deaths from seasonal flu annually” (or 2000-8000, or 4000-8000, or….I’ve seen several different estimates, but all in this range), and given that Alberta has about 10% of Canada’s population, I’d expect 200-800 deaths from seasonal flu here on average.  So 25 seems low, even factoring in that we are early on in the flu season. On the other hand, in a report from Alberta Health Services themselves—click the blue “Pandemic (H1N1) 2009 Response Plan” button to open the report as a pdf file—at the end of the second paragraph on page 7 it states:

“Seasonal influenza usually results in about 17 deaths annually in Alberta…”

So could we either correct the typo (should 17 deaths be 170?), or change the story? I do not see how we can keep saying H1N1 is a “milder than usual flu” if this 17 number is correct. Yes, since more people are expected to catch H1N1 than seasonal flu, you could say it’s less virulent—it’ll kill a lower percentage of those it infects than seasonal flu does—but in assessing risk to yourself and your family, you need to consider BOTH how likely it is to develop serious complications, and how likely you are to catch the illness in the first place.

Really hoping for some clarification on this soon. My personal opinion is that the 17 number is a typo, but I’d love to know for sure. And you’d think Alberta Health Services folks would be a bit more careful in terms of double-checking their numbers before releasing documents to the public. But given the misguided way they handled the initial vaccine roll out here, perhaps not.

I quite like this map from the Globe and Mail, as it gives the stats on hospitalizations, ICU admissions and deaths from lab-confirmed H1N1 in the different provinces and territories, as well as for Canada as a whole. I particularly like that it gives both the raw numbers, as well as ‘how many per million’—by hovering my mouse over Alberta, I can see how any per million in my province are being put in ICU for confirmed H1N1, for example. The data is current to October 31, and is updated weekly after FluWatch Canada publishes its cumulative weekly report. For the most recent numbers, see FluWatch Canada’ surveillance page, as well as your own provincial health authority. Alberta’s is here. If you compare the the up-to-date numbers with this map, you’ll know to expect a big jump next week—and hopefully it won’t seem as alarming if you know its coming. It bears repeating: the risks of H1N1 are overall low, but are higher than seasonal flu for a few groups.

In my previous blogpost I discussed an argument I have seen given by many on the conspiracy/anti-vaccination side, and here I’m going to discuss another. But let me clarify—though I am taking these particular arguments to task, I am NOT pro-vaccination. I am not anti-vaccination either. I am trying my best (and no doubt falling short at times) to offer ways for you to make sense of the overwhelming stream of info coming at us about H1N1, and—as always—leaving your family’s health care decisions up to you.

Perhaps you’ve seen charts of pediatric deaths from flu like this out there (I am not going to reference the actual source on this, or give real numbers, as these people seem to have a LOT of folks (power? money?)behind them, but no doubt many of you have seen the kind of thing I am talking about):

• 2003 – 100 deaths (mass flu immunization campaign for kids)
• 2006 – 70 deaths
• 2007 – 75 deaths
• 2008 – 117 deaths (47% of kids ages 1-4 vaccinated for flu—footnnote (reference) given)

Wow! That sure looks like vaccination causes flu deaths, doesn’t it? I mean, why else would deaths be so high in years where vaccination rates are noted? Why would the extra comments about vaccination rates be included at al if there wasn’t something amiss here?

A couple things. First, did you notice data from a couple years are missing (2004 and 2005)? Perhaps why that is should be investigated—google away. And while 2003 looks bad, I can’t evaluate the claim as no reference is given. But a reference is given for 2008, and when I go find the original source, I do indeed find the (remember, I’m using ‘pretend’ numbers here) data given (47% of 1-4 year old vaccinated). That part of the data is indeed accurate. But reading on, I also find the following sentence (right after the data is provided, in fact):

These results are consistent with previous studies that have found no significant increases in vaccination coverage for any of these age groups over previous seasons. (actual sentence in MMWR from the CDC, near the end of the opening paragraph)

Hmmmm….so we’re given data for 2008 with its higher pediatric death rate, suggesting that something is significantly different about vaccination rates in this year which would explain the higher number of deaths, but when we check the original source, it explicitly says the vaccination rate was basically the same as in previous years. Hmmmm…..

Now let’s think further. What does “the 2008 flu season” mean? The 2008 flu season means the Sept 2008 through Aug 2009 season—the season we all just lived through. What do we know about this time? Well, there was an outbreak of H1N1 beginning in April and it claimed 43 children in this time in the US. And how many of those kids got flu shots? Not many (any?) as the flu vaccine only recently became available, and there is simply not enough to go around—complaints of H1N1 vaccine shortages are being heard around the globe. So do you still think that the most plausible explanation of these increased deaths in kids is that flu vaccine caused them?

I am going to leave you to do the research into the spike in pediatric deaths in 2003 yourself. I know from doing my own research on Canada pediatric deaths that 2003’s flu strain put more kids in hospital than usual—the virulence of flu varies from year to year. I don’t know if there were higher rates of flu vaccination for kids that year though. But, for the sake of argument, let’s suppose there was a higher rate of vaccination—what would this show?

When two events (A and B) are correlated—like our supposed flu vaccination rates and flu deaths for 2003, or smoking and lung cancer, or the number of people waiting at the bus stop and how quickly the bus comes—there are 4 possibilities:

1 - A causes B

2 - B causes A

3 - Both A and B are caused by a third factor C

4 – A and B are simply correlated, but there is no cause involved at all.

The trouble is that determining which one of these explanations (1, 2 ,3 or 4) is most plausible can be quite tricky. Let’s consider a year in which there is both a higher than usual number of flu deaths, and a higher than usual rate of flu vaccination. Which caused which? Did more folks getting vaccinated cause more deaths, or did more deaths cause more folks to get vaccinated (perhaps out of fear, as we are seeing right now)? Think about how this year’s stats are going to look in the future—in the 2009-2010 flu season, it seems likely to me that we will both have more pediatric deaths than usual (we’re almost there already in early November) and that the rate of child flu vaccination will also be higher than usual. Are already vaccinated kids dying at high rates, or are more people vaccinating their kids because they are more concerned about H1N1 than previous seasonal flus?

My point is that two events being correlated cannot alone prove cause. Those events being correlated (smoking, lung cancer) and a whole lot of other research—including clarifying the temporal relationship (generally people smoke FIRST and get lung cancer SECOND) helps establish cause. But the temporal relationship alone can also mislead. Most of us have noticed that the more people there are waiting for a bus when we get to the stop, the shorter our wait time for a bus—not always, of course, but this correlation generally holds true. But to infer some kind of causal relationship between the two is absurd: we all know we don’t make the bus come any faster by taking a gaggle of friends along with us to the bus stop! This is a case in which A (many folks at stop) and B (bus coming sooner) are either causally unrelated, or explained by a third factor C: both people and bus drivers are adhering to the same bus schedule.

I hope this is helpful to those of you trying to make sense of the media blitz on H1N1 and elsewhere.

The latest CDC data  (thru Oct. 24) says that there have been 114 pediatric deaths from H1N1, a number higher than normal for flu. At the same time, there are a number of blogs, news reports and so on trying to convince us that H1N1 is either (a) some kind of giant conspiracy or (b) being blown out of proportion, and they make arguments like this :

H1N1 is really no big deal for kids. There’s only been 74 pediatric deaths so far this flu season—last flu season there were 117!

Some even provide support for this claim from the CDC itself, which shows this chart:

 

Did you spot the “how to lie with statistics” move here in the attempt to convince you that H1N1 is no big deal for kids? Because everything I have said so far is true: there have been 114 pediatric deaths in the US from H1N1, 117 pediatric deaths last flu season and 74 this flu season. How can all three of these claims be true at the same time?

It’s simple: “Last year’s flu season” means the 2008-2009 season, and in the US these stats count deaths from September 2008 to the end of August 2009. Included in the 117 total from last year is 43 deaths from H1N1 itself. You can see this in the graph—the first clump of pink deaths (H1N1) actually belongs to the 2008-09 flu season stats—it’s not that all the pinks are being clumped together to get the 74 total of 2009-10. (And yes, the CDC could do a WAY better job of presenting this data so that it does not so easily lend itself to being misrepresented!)

So ask yourself, what really matters to you in assessing the risks of H1N1 to your own family? How many pediatric deaths there are in one flu season or another? Or how many pediatric deaths are due to H1N1, and how this compares to the usual totals from seasonal flu in previous years? Further, it seems to me that if the point of your website/blog/news report is to convince folks that H1N1 is not a big deal for kids—no worse than any seasonal flu, in fact—then your proof of this needs to compare H1N1 stats to seasonal flu stats. Conflating things by talking about “last year’s flu season” and “this year’s flu season” instead of “H1N1 vs. seasonal flu” data is deeply misleading. The 43 deaths that occurred from H1N1 itself among US kids from April-August 2009—which is why we get the high 117 figure for 2008-09—are being used to argue against the risks of H1N1 to kids!

But let me repeat again: the overall risk of H1N1 to kids is very low; only a VERY SMALL minority of kids develop serious complications to the disease. But the risks of death/serious complications for kids from H1N1—very low though they are—are clearly higher than the risk posed by seasonal flu. Whether this risk is high enough to warrant vaccinating your child is a different question, and one that I leave up to you.

While reading this article which was actually referenced off an anti-vaccination site I found this really important bit about vaccine efficacy and effectiveness. Let me give you the quote and then we’ll unpack it, ok?

Evaluating Influenza Vaccine Efficacy and Effectiveness Studies

The efficacy (i.e., prevention of illness among vaccinated persons in controlled trials) and effectiveness (i.e., prevention of illness in vaccinated populations) of influenza vaccines depend in part on the age and immunocompetence of the vaccine recipient, the degree of similarity between the viruses in the vaccine and those in circulation (see Effectiveness of Influenza Vaccination when Circulating Influenza Virus Strains Differ from Vaccine Strains), and the outcome being measured (my emphasis). Influenza vaccine efficacy and effectiveness studies have used multiple possible outcome measures, including the prevention of medically attended acute respiratory illness (MAARI), prevention of laboratory-confirmed influenza virus illness, prevention of influenza or pneumonia-associated hospitalizations or deaths, or prevention of seroconversion to circulating influenza virus strains. Efficacy or effectiveness for more specific outcomes such as laboratory-confirmed influenza typically will be higher than for less specific outcomes such as MAARI because the causes of MAARI include infections with other pathogens that influenza vaccination would not be expected to prevent (81) (my emphasis). Observational studies that compare less-specific outcomes among vaccinated populations to those among unvaccinated populations are subject to biases that are difficult to control for during analyses. For example, an observational study that determines that influenza vaccination reduces overall mortality might be biased if healthier persons in the study are more likely to be vaccinated (82,83). Randomized controlled trials that measure laboratory-confirmed influenza virus infections as the outcome are the most persuasive evidence of vaccine efficacy, but such trials cannot be conducted ethically among groups recommended to receive vaccine annually.

I first made mention of this difference between efficacy and effectiveness, and its importance, in my original blogpost about H1N1/swine flu. I am pleased to say that I understood the terms correctly: ‘efficacy’ looks at how well the vaccine prevented flu in proper controlled (scientific) trials; ‘effectiveness’ looks at how well the vaccine worked to prevent flu in vaccinated populations—but—and here is the really important point—this was not always measured by looking at the rates of flu itself! (i.e., the illness that the flu vaccine is supposed to prevent). Effectiveness (or efficacy) of flu vaccine has been assessed by looking at different “outcome measures", including:

the prevention of medically attended acute respiratory illness (MAARI)—this often attends flu, but not always, as can be present in those without flu (i.e. just pneumonia)

prevention of laboratory-confirmed influenza virus illness,—what I would have expected such studies to assess: do they reduce flu?

prevention of influenza or pneumonia-associated hospitalizations or deaths,—a better outcome than the first, but again we have the possibility that flu is not a factor in some of these deaths

prevention of seroconversion to circulating influenza virus strains. (I am not going to discuss this, as quite frankly, I don’t understand it, and its not necessary to make my point).

Since efficacy / effectiveness studies do not just look at whether or not lab-confirmed flu rates are decreased by vaccinating, I can now see why the effectiveness rates, in particular, can be so low in some studies. As the authors put it:

the causes of MAARI include infections with other pathogens that influenza vaccination would not be expected to prevent

Now, it would take further investigation to find out if efficacy studies (controlled trials) tend towards measuring outcomes in terms of rates of lab-confirmed flu (which I would think they would, as controlled studies are generally smaller than population studies, so its easier to lab-test everyone), and if effectiveness studies (vaccinated populations) tend towards measuring outcomes it terms of deaths or MAARI-type illnesses, hospitalizations and the like. This could explain the high efficacy yet low effectiveness rate of flu vaccines in studies. Any takers?

But regardless, I now have a very different idea about what looking at the efficacy or effectiveness of a flu vaccine means: I want to know if the study in question looked at lab-confirmed rates or flu, or not. Because—and I have to say this kind of shocks me—not all studies on the subject do.

A friend recently sent out this blogpost from someone named “Alix”on an email list—it’s now making the rounds on facebook—and I thought an in depth discussion of it would make for a possibly interesting (if long!—go get yourself a snack and a cuppa!) blogpost. Here’s the highlights:

1 – Her math is off. If 1 in 100,000 (or 10 in 1 million) flu shots lead to adverse affects, as they did in 1976, we’d expect (at most!—if all Americans get the H1N1 shot) 3000 adverse effects from H1N1 shots in the US, not that “30,000+ Americans will get Guillain-Barre Syndrome or die” as Alix claims. It is also important to note that about 80% of all GB patients make a full recovery with treatment, and that the 1976 death rate from the swine flu shot (25/40 million, or 0.625 per million) is far lower than the current (and rising) death rate from the 2009 outbreak of H1N1 in the United States (even ignoring 2916 deaths from
influenza and pneumonia syndrome listed at the CDC): 1123 deaths / 308 million people = 3.646 deaths per million.

2 – While some studies show Vit D to have a protective effect on colds and flus, not all do. A recent one found no such effect. I am afraid there are no guarantees in medicine:

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=6103912

3 – Much of her argument rests on another blogpost of hers, which provides data supposedly showing that flu shots do not work for any groups of people: babies, children with asthma, adults, the elderly. If you go and look at the referenced studies, however, you will find her arguments present the data in deeply misleading ways, such as referencing a paper to argue that flu shots are ineffective in children under two, but conveniently ignoring the fact that that EXACT SAME PAPER shows flu vaccines to be highly efficacious, and of moderate effectiveness, in children over 2—something the authors explicitly state. Could this be why her argument did not look at the effectiveness of flu shots in “children”, but only “children with asthma” (and even those studies are were misused in various ways—see below).

Curious for the details? Here goes, starting with point 3:

If you click on one of the links an Alix’s original page where she backs up her argument, you end up on this page:

http://www.mednauseam.com/2009/09/its-seasonal-flu-shot-seasonbut-shot.html

which claims to show that flu shots don't work for various groups of people (babies, children with asthma, adults, the elderly). And, better than many who make this claim, references are given. So let's start at the beginning:

Babies. Absolutely correct--the studies (very limited—ONE study!) show no better result than a placebo. The authors stress that if public policy is going to be that children 6 months thru 24 months be immunized for flu, we need more evidence--ONE study is simply not enough to base public policy on, for or against. Here's their words:

It was surprising to find only one study of inactivated vaccine in children under two years, given current recommendations to vaccinate healthy children from six months old in the USA and Canada. If immunisation in children is to be recommended as a public health policy, large-scale studies assessing important outcomes and directly comparing vaccine types are urgently required.

ref: http://www.cochrane.org/reviews/en/ab004879.html

Next group: children with asthma (x2)

What? Huh? Why is there no group simply labelled “children”? Would it have anything to do with the fact that the VERY SAME study referenced above for babies says that flu vaccines are highly efficacious and of moderate effectiveness for children older than 2? This seems to me to be a clear case of confirmation bias—mining the data for claims that support your already-decided-upon conclusions, rather than presenting the evidence both for and against and letting folks decide for themselves how to weight competing evidence and what this means for their own decision re: vaccinate or not. Here again are the authors of the above-quoted study:

Fifty-one studies with 294,159 observations were included. Sixteen RCTs [me: randomized controlled trials] and 18 cohort studies were included in the analysis of vaccine efficacy and effectiveness. From RCTs, live vaccines showed an efficacy of 82% (95% confidence interval (CI) 71% to 89%) and an effectiveness of 33% (95% CI 28% to 38%) in children older than two compared with placebo or no intervention. Inactivated vaccines had a lower efficacy of 59% (95% CI 41% to 71%) than live vaccines but similar effectiveness: 36% (95% CI 24% to 46%).

And again:

Influenza vaccines are efficacious in children older than two but little evidence is available for children under two. There was a marked difference between vaccine efficacy and effectiveness. [me: For more on the difference between efficacy and effectiveness, see my original blogpost on H1N1/swine flu and this more recent post]

Ok, so let’s get back to the next group listed on Alix’s page: children with asthma (Christy et al). The title of this study tipped me off, and sure enough, looking it up on the web we discover this study says NOTHING WHATSOEVER about whether or not flu shots work in children with asthma: it says that flu shots do not prevent asthma exacerbation (asthma attacks?), and in fact, may cause an increase in asthma attacks. This is important data, to be sure—and as the parent of an asthmatic I am going to look at this more closely—but the fact remains that this study is IRRELEVANT for the question of whether or not flu shots prevent flu in asthmatic children. Next...

Children in asthma (2). This study is taken from a conference, which may mean it has not yet been published or peer-reviewed according to my hubby who did grad work in science. I am curious if it was the preliminary data on this that led the US to adopt the policy of not giving FluMist to asthmatics. This data, if correct (again, I am unsure if it has been peer-reviewed or shown replicable, but I would accept it for now) shows that FluMist is not preventative for asthmatics wrt hospitalizations for flu. But there is simply not enough evidence from this to say whether or not flu vaccines of the injectible type prevent such hospitalizations, and therefore, we can’t make any large sweeping conclusions about whether or not flu vaccines work for asthmatic children. Or children in general. And again, FluMist is NOT offered to asthmatics in the United States. Next…

In adults. I cannot find the quote Alix gives:

Vaccination of healthy adults only reduced risk of influenza by 6% and reduced the number of missed work days by less than one day (0.16) days. It did not change the number of people needing to go to hospital or take time off work.

provided in the abstract I was able to locate online, but this is what I did find when I looked up the study in question:

Authors' conclusions

Influenza vaccines are effective in reducing cases of influenza, especially when the content predicts accurately circulating types and circulation is high. However, they are less effective in reducing cases of influenza-like illness and have a modest impact on working days lost.

Ref: http://www.cochrane.org/reviews/en/ab001269.html

Yes, despite the authors explicit statement that flu vaccines are “effective in reducing cases of influenza”, this study is being used by Alix to support the claim that flu vaccines are ineffective in adults. Here’s more from the abstract:

Main results

Forty-eight reports were included: 38 (57 sub-studies) were clinical trials providing data about effectiveness, efficacy and harms of influenza vaccines and involved 66,248 people; 8 were comparative non-randomised studies and tested the association of the vaccines with serious harms; 2 were reports of harms which could not be introduced in the data analysis.

Inactivated parenteral vaccines were 30% effective (95% CI 17% to 41%) against influenza-like illness, and 80% (95% CI 56% to 91%) efficacious against influenza when the vaccine matched the circulating strain and circulation was high, but decreased to 50% (95% CI 27% to 65%) when it did not. Excluding the studies of the 1968 to 1969 pandemic, effectiveness was 15% (95% CI 9% to 22%) and efficacy was 73% (95% CI 53% to 84%). Vaccination had a modest effect on time off work, but there was insufficient evidence to draw conclusions on hospital admissions or complication rates. Inactivated vaccines caused local tenderness and soreness and erythema. Spray vaccines had more modest performance. Monovalent whole-virion vaccines matching circulating viruses had high efficacy (VE 93%, 95% CI 69% to 98%) and effectiveness (VE 66%, 95% CI 51% to 77%) against the 1968 to 1969 pandemic

No one here is claiming 100% effectiveness, but they are certainly not saying vaccines are ineffective for adults either, as Alix claims. I found it interesting to note that when data from the 1968-69 pandemic is excluded, effectiveness went down. This must mean, statistically speaking, that for the 1968-69 pandemic the flu vaccine was more effective than normal. I am wondering if the same is true of this year’s vaccine, for the reason that production got started later than usual (hence the current world-wide vaccine shortages). Is this year’s vaccine more likely to be a good match for the circulating strain (novelH1N1) as it H1N1 would have had less time to mutate? I have seen various bodies (WHO, CDC) claim this year’s vaccine is an excellent match, but have yet to see good data. Back to the next group Alix lists...

The elderly. The claim is made that for the elderly living in nursing homes, flu shots were “non-significant for preventing the flu”, whereas for elderly living in the community, flu shots were “not (significantly) effective in preventing flu, ILI, or pneumonia”. Well, right away the observant among you will notice that flu shots are claimed to be “not significantly effective” against different things for the two groups—the nursing home group (flu only) and the community living group of elderly (flu, ILI and pneumonia). Why would this be? From the study in question:

Best effectiveness of current vaccines in preventing clinical illness and its complications was seen in long-term care facilities (for example nursing homes) where vaccines prevented about 45% of pneumonia cases, hospital admissions and influenza-related deaths. This compared to about 25% vaccine efficacy in preventing hospitalisation from influenza or respiratory illness in open community settings. The public health safety profile of the vaccines appears to be acceptable. [from Summary]

Ref: http://www.cochrane.org/reviews/en/ab004876.html

While we’d all like to see higher effectiveness from the flu shot in preventing death in the elderly, if the CDC’s estimates of 36,000 deaths from flu or complications yearly—of which 90% of among the elderly—is correct, this would mean that even a 25-45% effectiveness rate in preventing pneumonia would save THOUSANDS of lives each year from pneumonia, to say nothing of those elderly who die of secondary infections picked up while in hospital. So while strictly correct in the claim that flu vaccines are not particularly effective in preventing flu in the elderly, they are effective (and the authors state so explicitly) in preventing hospitalization, pneumonia and all-cause mortality (which frankly is what does in many of the elderly when they get flu—its the complications from flu, not flu itself). The authors acknowledge that the difference between nursing home and community based effectiveness may be the results of other factors as well. Here again from the study:

Main results

Sixty-four studies were included in the efficacy / effectiveness assessment, resulting in 96 data sets. In homes for elderly individuals (with good vaccine match and high viral circulation) the effectiveness of vaccines against ILI was 23% (6% to 36%) and non-significant against influenza (RR 1.04: 95% CI 0.43 to 2.51). We found no correlation between vaccine coverage and ILI attack rate. Well matched vaccines prevented pneumonia (VE 46%; 30% to 58%), hospital admission (VE 45%; 16% to 64%) and deaths from influenza or pneumonia (VE 42%, 17% to 59%). In elderly individuals living in the community, vaccines were not significantly effective against influenza (RR 0.19; 95% CI 0.02 to 2.01), ILI (RR 1.05: 95% CI 0.58 to 1.89), or pneumonia (RR 0.88; 95% CI 0.64 to 1.20). Well matched vaccines prevented hospital admission for influenza and pneumonia (VE 26%; 12% to 38%) and all-cause mortality (VE 42%; 24% to 55%). After adjustment for confounders, vaccine performance was improved for admissions to hospital for influenza or pneumonia (VE* 27%; 21% to 33%), respiratory diseases (VE* 22%; 15% to 28%) and cardiac disease (VE* 24%; 18% to 30%); and for all-cause mortality (VE* 47%; 39% to 54%). The public health safety profiles of the vaccines appear to be acceptable.

Authors' conclusions

In long-term care facilities, where vaccination is most effective against complications, the aims of the vaccination campaign are fulfilled, at least in part. However, according to reliable evidence the usefulness of vaccines in the community is modest. The apparent high effectiveness of the vaccines in preventing death from all causes may reflect a baseline imbalance in health status and other systematic differences in the two groups of participants.

Two final things about the arguments found on this page of Alix’s:

1 – The vaccine in the United States does NOT contain adjuvants (i.e., squalene)

2—While some studies show a highly protective effect of Vitamin D3 on colds and flus and respiratory tract infections, not all do. Here’s a recent study that found no such protective effect:

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=6103912

Again, I’m all for folks making the vaccinate or not decision for themselves. And I am also all for folks doing proactive things from washing their hands to getting enough sleep to taking their vitamins (including D3!). But I do not think there is any magic bullet when it comes to H1N1—there is no way to guarantee you will avoid it, nor guarantee you will have only a mild case. This includes being vaccinated! What I do object to, though, is folks combing the data and only reporting back the bits that agree with their foregone conclusions. Please give BOTH sides and assume folks are intelligent enough to sort it out for themselves—whichever side of this debate you personally are on. It is clear to me that the data Alix is quoting, from Dr. Tenpenny, is misleading at best.

And to get back to Alix’s original page re: herd immunity, I actually agree with her overall stance on herd immunity (I’ve never been persuaded by these arguments), and I also agree that the risks of a live vaccine (a la FluMist) are not being properly accounted for. (I am genuinely confused on why this vaccine is being offered in the US given what we now know about the live polio vaccine as the sole cause of the rare cases of polio in the US. I also cannot find any other country using this version of the vaccine). But her assessment of the risks of Guillain-Barre is deeply misleading. The data I see most consistently agreed upon—including by folks who are clearly anti-vaccination, is that the 40-48 million swine flu shots in the US in 1976 led to 500-ish (532 to be precise) cases of GB, and 25 deaths. These stats show 13.3 folks per million injured from the shot (or, indeed, just over 1 in 100,000 as she says) but I think it need to be emphasized that the death rate was 0.625 per million (i.e., less than 1 in 1 million). It also needs to be emphasized that about 80% of folks make a complete recovery from GB with treatment (source: Wikipedia). The 2009 outbreak of H1N1 has killed 1123 Americans thru October 24^th, including 114 children. (These are confirmed H1N1 deaths only—593 from April-August, and 530 from Sept-Oct. 24^th; they do not include the 2916 deaths from “influenza and pneumonia syndrome”—source CDC):

http://www.cdc.gov/h1n1flu/updates/us/

and

http://www.cdc.gov/h1n1flu/updates/090409.htm

Assuming the population of the US is 307.839 million as of November 1, 2009 (source Wikipedia: http://en.wikipedia.org/wiki/List_of_countries_by_population) this is a death rate of 3.648 per million from H1N1 in the United States for the past (approx.) 7 months. This is far more than the death rate from GB in 1976 (0.625 per million), but far less than the GB rate post-1976 vaccination (13.3 per million), but again, slightly more than the number of those suffering lasting damage from GB (2.675 per million, assuming 80% of the 532 made a full recovery). And if the rate of “negative vaccine reaction” is similar to that of 1976, with 532 GB cases after 40 million shots, or 13.3 per million (0.625 dead), we would expect about 4096 GB cases (of which 80%, or 3276, recover fully), given 308 million Americans (let’s assume everyone gets a shot, and only 1 shot), and 193 deaths. I do not see ANY basis for Alix’s claim that “30,000+ Americans will get Guillain-Barre Syndrome or die.” Again, I can’t decide this for you, but I can give you (more) accurate information on which to base your decision.

And lastly, let me now put my cards on the table. Despite the fact that my family chose to get the H1N1 vaccination--based on our risk/benefit analysis of living with a child under 5 with asthma--I am NOT pro-vaccination. (This was in fact Gareth’s—our 4 ½ year old asthmatic’s—first immunization of any kind). Neither am I anti-vaccination. What I personally believe is that vaccines CAN BE one way to prevent serious illness, but as they can have serious side effects, and they are nowhere near 100% effective, we need to be considering a serious (possibly fatal) illness that at least sometimes leads to death EVEN WHEN PROPER MEDICAL CARE IS RECEIVED for me to even consider vaccinating (i.e., chicken pox, ear infections and rubella for my boys don't make the cut). But I am ADAMANT that folks need to decide for themselves on this, and frankly, they can't do so when data is being presented in misleading ways. I hope this has been helpful to those of you who read this far. Good luck making your own decision, and stay well.