Monday, November 26, 2012
This is flu season and once again we are all beset by groups screaming at you to get a vaccine and other groups screaming at you to not. Unfortunately there is so much information and misinformation out there that even the mighty Google can't give the full picture without confusing you further.
I do not presume to have the "answer" to the vaccination question and I am not going to offer my voice in support or opposition of getting a vaccine. What I am going to try to do however is bring you the story, offer up facts and sources in a single place (here) and hopefully this will help you to make up your own mind.
As is often the case my Facebook page was the inspiration for this post. A friend posted the above picture and after looking at it I started to ask questions. I wondered if the facts presented were correct, if the conclusion they led you to was correct (after all you can have a false conclusion even with correct data), and started debating if I should wade in to this wildly emotional debate.
The picture claims that flu vaccines contain 25 micrograms of mercury and that a vaccine is more dangerous than toxic waste. From a purely logical perspective the image is grossly skewed and misleading, lacking in context and using fear as a tactic. However, that doesn't mean the numbers are necessarily false.
There are several kinds of flu vaccine and SOME contain a preservative called Thiomersal (also thimersol). Thiomersal is an organomercury compound that has been used as a preservative in many vaccine acorss the globe for decades. However, since it does contain mercury it has been phased out and replaced with a non-mercury containing compounds in most vaccines, except a few flu vaccines (vaccines for infants lack mercury). (1)
Pure mercury has been a know toxic agent for many years, however that fact in and of itself is not really a reason to avoid it, after all oxygen is an explosive and it promotes damaging free radicals in the body. But, mercury in high doses is flat out bad for you. While there is no known biological role for mercury in the human body in low doses it can help prevent the growth of bacteria in things like vaccines.
Prior to thiomersal being used as a preservative there were accounts of people developing illnesses from the vaccines they received. The most famous case involved the death of 12 (out of 21) children in 1928 who were vaccinated for Diphtheria. The non-preserved multi-dose vaccine contained a deadly bacteria which the children contracted. (2)
Mercury toxicity hinges on two factors, dosage and exposure time. In other words a lot of mercury at once is toxic and being exposed to smaller amounts day after day (or other intervals) can all cause a wide range of ill effects, the most damaging occurring in children. And what people fail to understand is that its chronic (long term) exposure that would cause lasting harm with respect to vaccines.
Here are some facts: Of the 4 flu vaccine types listed on the FDA's site, only 2 contain 24-25 micrograms of mercury. The other 2 have less than 13. The 2 types with "high" levels are Fluzone and Afluria. (3)
Mercury concentrations in the blood are typically less than 6 mcg per liter, or about 31-33.6 mcg for the whole body. Of course a diet rich in fish can increase that level to 200 mcg/liter.
A vaccine with 25 mcg of mercury in it would be a single time exposure and is usually eliminated from the body within 7-10 days. The mercury found in fish, methyl mercury, can remain in the body for over a month. (4)
Since mercury exposure tends to involve small amounts it is the chronic exposure we must keep in mind. Long term exposure at levels of 1 mcg/day has been shown to cause tremors and other problems. However, again, the flu vaccine is a single time exposure. Short time (acute) exposure to mercury involve amounts far greater than the levels found in vaccines. A study on the trends of acute and chronic mercury exposure found concentrations ranging from 301 mcg to 1,918 mcg total blood levels or at least 12 times the amount found in a vaccine. (5)
Thiomersal has been claimed to cause autism and other neurological and developmental illnesses by a wide array of groups, including some scientists and doctors. However, there is no scientific consensus on the matter and the FDA, CDC, Institute of Medicine and the World Health Organization (6) have all rejected any role for thiomersal in autism or other neurodevelopmental disorders.(7) There is even a study that concludes the allegation of a connection is the "most damaging medical hoax of the last 100 years." (8) Of course that does not mean that beyond any shadow of doubt there are no connections or other negative side effects but rather the research they did simply didn't show any.
While mercury at large acute levels or small chronic levels can be dangerous we must look at the risks in the scope of a wider context, that of the illness itself.
The common flu kills, on average, 27,000 people each year in the United States(9) while major flu strains can kill millions. In 2009 between 151,700 and 575,400 died worldwide as a result of the H1N1 virus.(10) And of course everyone knows about the Spanish Flu pandemic in 1918 which killed at least 20 million people.
With a few exceptions vaccines do not claim to protect you from a disease 100% of the time. However the do provide a strong defense, especially for those with weakened immune systems. Flue vaccines do not protect you from the "flu", rather from 1-5 of the most common strains (the influenza virus mutates rapidly and comes in many strains). No drug is free from side effects, even drinking too much water can kill you, but when weighed against the risks, for many, getting a vaccine is the best thing to do. From a simple numbers perspective, Americans have around a 1 in 11,600 chance of dying from the flu this year without a vaccine. As a side effect risk you have about a 1 in 1 million chance of developing Guillain-Barré syndrome from a flu vaccine.(11) Having the right knowledge, proper expectations and realizing medicine is an ever growing, ever improving "practice" and not a flawless monolith of perfection will take you far.
In the end what is right for you and your body is your business. I just hope that when making any decision you look at all the facts, keep them in proper context and have a good relationship with your personal doctor and talk out your worries.
1. Mercury Poisoning -Thiomersal, Wikipedia (only for general information)
2, 3.Vaccine Safety, FDA
4. Methyl mercury Exposure, (requires paid subscription)
5. 1989-1990 Acute and Chronic Mercury Poisoning Trends, CDC
6. Thiomersal and vaccines, WHO
7. Immunization Safety Review Committee (PDF requires free subscription)
8. The Vaccine-Autism Connection, University of Charleston School of Pharmacy
9. Mortality due to Influenza in the United States, Princeton University
10. Global Estimates of 2009 H1N1 Pandemic, CDC
11. Flu Shot FAQ, CDC
Mercury Exposure and Public Health (requires paid subscription)