Sunday, December 6, 2009

Denialism or Realism?

Vaccines are one of the greatest medical accomplishment of past century and are perfectly safe .... or they are responsible for causing an epidemic of autism.  Most people stand on one side or the other in this debate with very few in the middle.

The reality of the situation is not so cut and dry.  Vaccines are a life saving invention that are mostly safe and, at the same time, can (and do) cause side effects.  The side effects run the gamut from the benign injection site swelling to the more serious conditions like Guillain-Barré syndrome right up to (in rare circumstances) very serious ones like death.

This situation is not anything out of the ordinary - almost everything in life involves some sort of trade off between risks and rewards.   I would have to say that most people are willing to accept risks when they understand what they are.  Take for example the fact that millions choose to get behind the wheel of the car every single day even though tens of thousands die each year in fatal car crashes.  People know they there is a chance of serious injury or death, but they are willing to accept the risks.   I believe the part of the reason for this is that the risks are openly acknowledged - when you get behind the wheel of a car you know what to expect.

The problem with vaccines is that an honest dialog about risks and rewards is all but impossible.  The current party line by the medical community and the media is that vaccines are perfectly safe and effective but any rational person knows that statement is not completely true.  I don't know about you, but I get very tired of people saying things that they know are not the true.  Yes, vaccines are (mostly) safe but, at the same time, they have to be honest about the reality of the situation and not deny the risks.

As a case in point, look at author Michael Specter.  Mr Specter wrote a book called Denialism that is about "How irrational thinking hinders scientific progress, harms the planet, and threatens our lifes". I would agree with the basic premise here - too often people are irrational about important subjects and don't take the time to understand what it is that they are talking about.  Mr. Specter proved this himself on a recent appearance on The Daily Show where he made the following statement (at about 1:00 in the video) -
There is flu virus going around that half of americans adults say they won't vaccinate themselves or their children against.  62 million people have received this vaccination and zero people have been shown to have been killed or seriously injured.  So zero - 62 milllion, thousands dead without the vaccination, it doesn't seem like a difficult calculation to do.
This is a perfect example of skewing reality for the sake of proving a point.  Mr Specter is correct - this isn't a difficult calculation.  What I have a hard time understanding is why he exaggerated his numbers and denied the risks involved with the H1N1 shot.

Lets start with the assertion that 62 million people have been vaccinated against H1N1.  A quick check at the CDC shows that number is wrong -
During October 5--November 20, a total of 46.2 million doses of H1N1 vaccines (11.3 million LAMV and 34.9 million MIV doses) and 98.9 million doses of seasonal influenza vaccines were distributed to U.S states and territories
The 46.2 million is the number of doses - not the number of people who received the vaccine.  Keep in mind that for some groups (children), the recommendations call for 2 doses of the vaccine.  And I would assume that there are still some vaccine doses that have not been administered yet.

As a result, I would guess that a more realistic number of vaccinated people would be 40 million.  But for the sake of argument, lets assume for a moment that a full sixty two million people have been vaccinated against H1N1. Would that have mean that thousands of lives were saved?

To answer this question, we first have to know how common the flu is and then what the mortality rate is.  According to estimates from CDC, around 7 percent of the population is expected to catch the flu and approximately 18 out of every 100,000 was expected to die from the flu or complications from the flu.

The next question to ask is how effective the flu vaccine is at protecting against the flu.  There are no real figures available for the H1N1 vaccine but the regular flu vaccine is though to be 70 to 80 percent effective (when it matches the circulating strain of the flu).  For the sake of argument, lets assume that 75 percent of the people would have been protected.

Putting all of these numbers together - out of the 62 million, about 4.5 million people would be expected to catch the flu.  Out of that group about 800 people would have been expected to die.  Now assuming that the vaccine would have prevented 75 percent of these cases, we are left with about six hundred lives saved.

While it would be a good thing to save six hundred lives, six hundred is much less than the "thousands" claimed by Mr. Specter.  And when you adjust the sixty two down to the more likely 40, what you would find is the number saved would be under 400.

To put these numbers in perspective, the CDC puts the (confirmed) death toll for all types of flu this season (Aug 30 - Nov 28th) stands at 1,336.  If you use the same estimates figures from above, you would find that the confirmed death toll would likely be 250 higher if people were not vaccinated.

As for the second claim, the one that zero people have been shown to have had a serious reaction to the vaccine, another trip to the CDC puts that claim to rest -
Through November 24, VAERS received 3,783 reports of adverse events after receipt of H1N1 vaccine, of which 204 were categorized as serious, and 4,672 reports after receipt of seasonal influenza vaccines, of which 283 were serious. [Snip]
VAERS received 13 reports of deaths occurring after receipt of H1N1 vaccine; three deaths occurred after receipt of LAMV and 10 after receipt of MIV (Table 2). In nine of these deaths, significant underlying illness (including illness that might be indication for vaccination) was present; one death resulted from a motor vehicle crash, and the remaining three deaths await review of final autopsy results or death certificates by CDC.
These numbers are very rough and just because something was reported to VAERS doesn't mean it was an adverse reaction to the vaccine.  But, I think it is reasonable to assume that a good number of these adverse effects were actually related to the vaccine and that puts the figure well above zero.

If Mr. Specter had limited his claims to the facts, his point would be better received. Perhaps he could have said hundreds of lives were saved and mostly mild side effects have been seen.  But whatever the reason, he did not stick to the facts - he exaggerated the rewards and denied the risks.

This approach is all too common when talking about vaccines and therein lies the reason that the autism-vaccine wars aren't going to end anytime soon.


  1. Why is it so difficult for some of these pro-vaccine folks to understand that people are different and that some people might have a very bad reaction to a vaccine or its ingredients? Just because they can prove that some people are fine after getting vaccines doesn't mean that everyone actually is. That would be like saying that since some people can eat peanuts that everybody should be able to eat them without experiencing anaphylaxis.

  2. That is the question.

    If you come up with an answer as to why people are so threatened when the safety of vaccinations are questioned, let me know.