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Influenza Vaccine Illusion

by Stephen Propatier

September 11, 2013

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Donate Recently I was forwarded a story from the National Vaccine Information Center by a fellow vaccine advocate. NVIC is a non-profit and extremely well funded US anti-vaccination organization. In skeptical groups NVIC is well known for their expensive and very slick anti-vax propaganda. In 2011 they attempted to have an anti-childhood vaccination ad run on Delta Airlines flights(a captive audience). A grass roots skeptics campaign and a petition helped nix that. The title of this particular article is compelling "Effectiveness of Flu Vaccine Raises More Red Flags", but not shocking given the origin of the article. The substance of the article itself is an example of a mainstay of the anti-Vaccine community. Utilizing the language of science without the substance. On the surface the arguments appear compelling. They are cross referenced with the CDC and other reputable journals. Close scrutiny quickly erodes the argument.

Reading the evidence in this article made me recall a scene from the movie My Cousin Vinny-1992. Where Joe Pesci's character Vinny uses a playing card as analogy for the evidence against his cousin "He's going to show you the bricks. He'll show you they got straight sides. He'll show you how they got the right shape. He'll show them to you in a very special way, so that they appear to have everything a brick should have. But there's one thing he's not gonna show you. When you look at the bricks from the right angle, they're as thin as this playing card. His whole case is an illusion, a magic trick." The evidence in this article is the same as that playing card. It is a illusion presented in just such a way as to be favorable way for the Anti Vaccine Community. Just like that playing card in the movie, the evidence is very thin.

The flu vaccine is a popular anti-vax topic since it provides the most talking points. The public's opinion of the influenza vaccine is riddled with confirmation bias, poor understanding, and self deception. The vaccine's efficacy is complicated. Complication results in misunderstanding. Misunderstanding is weakness that can be exploited. Not surprisingly the Anti-Vax community takes full benefit of the complexity of the Flu vaccine.

This article manages to hit all the low points of the vaccine while omitting the benefits. It draws a very specific picture of the flu vaccine. A one sided discussion that fails to properly disclose the pluses and minuses of the vaccine. For clarity it is important to understand that no vaccine/medical treatment is perfect. Treatment decisions are always a benefits vs risk discussion. Anti-vax discussions consistently and conveniently omit the benefits of a vaccine.

The article leads with this troubling statement.
The news may be well known now about the influenza vaccine being only 56 percent effective overall and 9 percent effective for the type A H3N2 strain in adults aged 65 years or older during the 2012-13 flu season. The latest buzz, however, is about how getting a flu shot year after year may make people more susceptible to getting influenza.
Followed by:
This is not the first study questioning vaccine effectiveness based on repeated annual influenza vaccination. In fact, there is a large body of literature examining the impact of previous use of seasonal trivalent flu vaccines on the risk of contracting the 2009 pandemic H1N1 swine flu.
The author finishes with a ominous sounding warning about physician concerns related to the seasonal flu vaccine:
In an accompanying editorial, Drs. John Treanor and Peter Szilagyi wrote a response to the findings for the most recent study showing lower effectiveness with back-to-back flu shots.

"As we are currently struggling through one of the most vigorous influenza seasons in recent memory, the apparent failure of influenza vaccine under optimal conditions seen in this study is indeed troubling," they wrote.
She concludes with what sound like a very reasonable opinion given the body of her article.
As usual, further study on flu vaccine effectiveness is necessary. There are a lot of conflicting data available. However, the growing number of studies showing low overall effectiveness, waning immunity and a negative effect of prior-year vaccination cast doubt on influenza vaccine policies and strategies, especially when influenza vaccinations now are being required as a condition of employment for health care workers.
As you probably have guessed I do not agree. The influenza vaccine is a complicated public health issue due to a variety of factors. It's effectiveness is well understood as well as the limits. Lets address the authors talking points systematically and see the merits and failures.

Lets begin with the call for "further study on the flu vaccine effectiveness". There is tons. This is not some experimental treatment. It has a long track record of safety and efficacy. On just the CDC site there are 14 recent references related to seasonal flu vaccine. There is a page of research at the CDC supporting the effectiveness.

This is a common ploy in the Anti-Vaccine community, "we need more research". Sounds very reasonable. When you have mountains of data how much more do you need? In my opinion there will never be enough research to change their mindset. It is an empty statement. If you do not respond to evidence you will never have enough evidence. Yes, there is a lot of conflicting data when you cherry pick negative studies and hold them up one to one against contrary studies. It appears to have similar weight and cause for concern. When you look at the body of work you will see clearly see that safety and efficacy is proven.

So what do we actually know about the vaccine's efficacy? Estimates of influenza vaccine effectiveness are affected by several factors, including the specific study biases, the match between the vaccine influenza strains and the circulating strains, host factors and the sample size of research. Simply put Influenza is a rapidly changing virus. Vaccine effectiveness will always vary from season to season, based upon the degree of similarity between the viruses in the vaccine and those in circulation, as well as other factors. In years when the vaccine strains are not well-matched to circulating strains, vaccine effectiveness is generally lower. In addition, host factors also affect vaccine effectiveness. In general, influenza vaccines are less effective among people with chronic medical conditions and among people age 65 and older, as compared to healthy young adults and older children. Like I said complicated.

More importantly the author has left out exactly what the 56 percentage means. Using CDC figures has a specific meaning. A Vaccine Effectiveness point estimate of 60% means that the flu vaccine reduces a person's risk of developing flu illness that results in a visit to the doctor's office or urgent care provider by 60%. In other words it is a measure of seeking out medical care for the flu. Not a description of how effectively the vaccine protects you from the illness either in morbidity or mortality.

Research from the American Journal of Epidemiology in July 2009 published a very extensive analysis of mortality impact in the elderly. In?uenza Vaccination and Mortality: Differentiating Vaccine Effects From Bias. This research showed a 47% reduction in mortality in the elderly who received the flu vaccine. During a regular flu season, about 90 percent of deaths occur in people 65 years and older.

The author does quote actual research but the results are irrelevant. The quoted study was a 1400 subject non-randomized study. There was evidence of poor performance of the vaccine. Plus there was a correlation with previous years vaccine administration and a higher failure rate. Surprising findings but by no means conclusive. This is what a scientist would call a single correlational, uncontrolled, non-randomized and unreplicated study. It is not rigorous enough to state that previous seasons vaccinations suppress effectiveness the following year. That is exactly what the author is implying. The research is interesting but not in any way convincing. It lacks all the necessary elements to cause real concern, duplication, multiple lines of evidence, and well controlled randomized studies.

Here is the real problem with all the data mining going on here. Influenza vaccine controlled studies are by themselves ethically impossible. There is no way to properly do them with this disease. Are you going to knowingly infect people? Even if you could ethically do it, what is the endpoints for those studies? Death, influenza positive, specific symptoms, or subjective complaints? Perhaps the flu will not be prevented but it will be attenuated, so it is less likely to spread, and overall the secondary complications of influenza will decrease in a population. In medicine benefit for this vaccine is messy and multi-factoral.

Again a binary approach to the vaccine you get the flu or you don't. The binary approach doesn't work with this vaccine. In reality a milder case of flu due to the vaccine will lead to fewer complications and deaths. You must accept that the influenza vaccine, unfortunately, is not like the tetanus vaccine, but its effects are more like a continuum. If you are simplistic and love binary answers, yes or no, then you can pick yes or pick no, and find studies to support your contention. Then feel justified about that decision. Truth is Influenza vaccines are effective(not as good as we would like), and extremely safe.

It is, in my opinion, very narcissistic and selfish to only consider personal benefit from the vaccine into account. Influenza immunization benefit is not just from the individual but from Herd Immunity. That is the true benefit to the vaccine, altruism. We are looking out for everyone. We are providing protection for strangers, loved ones, and friends when we get vaccinated. We are allowing for the short comings of the vaccine but giving the maximum benefits to our neighbors. Thanks to the type of propaganda in this article we will never ever get the kind of rates we need to achieve true herd benefit from the influenza vaccine.

So if you buy the fact that a single study guides medical care or that the flu vaccine must have 100% personal efficacy then yes this article is concerning. It is a limited point of view that purposefully obfuscates the overall benefit of the vaccine and magnifies a singular negative result. Not a new trick for the Anti-vaccine crowd.

If you think that it is not worth a tiny risk to protect your aunt, your grandmother, and your sisters infant son, by all means stay away from the terrible horrible injection. If you are an MD, RN or any healthcare worker you get zero sympathy from me. If you cannot accept a tiny amount of pain to protect your patient, what gives you the right to expect them to accept the same at your urging? If you think the small health risks of a vaccine are unacceptable what are you doing around sick people anyways? Do not lie to yourself about it. Face the fact that you are looking for reason to not get the Flu Shot when you listen to this type of article. There are small risks to any vaccine. You take a risk when you let your children go to school, drive a car, eat raw seafood, or take any herbal supplement. Will any of those things help keep the elderly safe or protect infants?

Fact: The flu vaccine is very effective and safe, is it perfect? No it is not. Does the vaccine have a large upside with very little downside? Yes it does.

Think about it, the life you save may be someone you love.


Am. J. Epidemiol. (2009) 170 (5):650-656.doi: 10.1093/aje/kwp173First published online: July 22, 2009

2 Ohmit SE, Petrie JG, Malosh RE, et al. Influenza Effectiveness in the Community and the Household. Clinical Infectious Diseases Feb. 14, 2013.

6 Treanor JJ and Szilagyi P. Influenza Vaccine: Glass Half Full or Half Empty? Clinical Infectious Diseases Feb. 14, 2013

Disclaimer: This post is my personal opinion it does not reflect the opinion of; my practice, my partners, hospital, Brian Dunning or my academic affiliations. It is for informational/educational purposes only. It is not intended to replace personal medical evaluation and discussion with your healthcare provider.

by Stephen Propatier

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