Guillain-Barré Syndrome and the H1N1 Vaccines

Guillain-Barré Syndrome (GBS) is thought to be an auto-immune disease of the peripheral nervous system. A patient’s immune system attacks its own Schwann cells. These Schwann cells wrap around peripheral nerves and help speed the transmission of nerve impulses. The attack on the Schwann cells that occurs in GBS causes demyelination, an unwrapping of the Schwann cells. This results in much slower nerve transmission. The result can be a sudden, severe paralysis. With proper supportive care, patients usually make a nearly complete recovery, although there may be residual deficits.

The precise cause of GBS is still under investigation, but a correlation between infections with pathogens like Campylobacter jejuni and GBS have been reported. One hypothesis is that there are small groups of amino acids within the pathogens that also happen to be found on the Schwann cells. The patient’s immune system makes antibodies to fight the pathogen. Unfortunately, these may also turn out to attack the Schwann cells. One way to think of this is as friendly fire during the fog of war.

Although the most evidence has been developed for Campylobacter jejuni infection preceeding GBS, other pathogens may also trigger this “friendly fire”.  Among these is influenza (Sivadon‐Tardy, et al. 2009). Since the purpose of the flu vaccine is to stimulate the immune system to respond as if it was being infected, then it would not be surprising if a vaccine itself could cause GBS. However, for most flu vaccines, there is little evidence of such an effect. One exception is the 1976 swine flu vaccine. It is estimated that 1 in 105,000 people needed to be hospitalised as a result of GBS, presumably caused by this vaccine. 25 people, out of 40 million vaccinated, are estimated to have died as a result of vaccine-induced GBS.

Recently, there have been dramatic headlines indicating concern on the part of some neurologists that vaccines to the new H1N1 virus may cause GBS. How serious is this risk? Frankly, we don’t know. The 1976 swine flu and the new H1N1 virus have little in common. So, extrapolating from the vaccine from 1976 and the ones being developed today is risky. However, for the sake of argument, let us say that the risk will be the same, 1 in 105,000 people will need to be hospitalised. Deaths are likely to be lower because supportive care is much better now than in 1976. Let us now consider this risk in comparison with the risk from the pandemic flu virus itself using the leaked CDC case fatality rate numbers. We will also assume a clinical attack rate of 30%.

If you are 25-49 (CFR = 1.5%), your odds of dying of the new flu are 1 in 222.

If you are 50-64 years old (CFR = 3.33%), your odds of dying in the pandemic are 1 in 100.

Since essential workers are primarily in these two age groups, a good case can be made that vaccinating this group.

Pregnant women and children with neurocognitive and neuromuscular disorders also have greatly elevated odds of dying from the new H1N1 virus. Thus, the risk-benefit ratio for vaccinating people in these groups is also likely to be favorable.

The CFR for school age children is 0.22% (according to the leaked CDC document). The risk for this group is 1 in 1,515 that they will die in this pandemic. This risk is substantially less than the other groups, but still much greater than developing GBS after vaccination (assuming 1976 numbers).

We cannot be certain of any of the numbers in this exercise. However, any discussion of the risks and benefits of vaccination should take place in the context of the best quantitative information we have. In my opinion, the risk of the pandemic virus is far greater than the risk of getting GBS from a vaccine. But that risk is not zero. People have a right to know all of these numbers so that they can make informed decisions about whether or not they wish to be vaccinated.



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5 Comments

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5 responses to “Guillain-Barré Syndrome and the H1N1 Vaccines

  1. What are the plans for developing 2009 H1N1 vaccine?
    Vaccines are the most powerful public health tool for control of influenza, and the U.S. government is working closely with manufacturers to take steps in the process to manufacture a 2009 H1N1 vaccine. Working together with scientists in the public and private sector, CDC has isolated the new H1N1 virus and modified the virus so that it can be used to make hundreds of millions of doses of vaccine. Vaccine manufacturers are now using these materials to begin vaccine production. Making vaccine is a multi-step process which takes several months to complete. Candidate vaccines will be tested in clinical trials over the few months.

  2. James McIntosh

    I had an attack of Gullain-Barre-Syndrome in 2003. I had some problem in my feet but nearly recovered. I have some numbness in my right leg and foot plus numbness in my right buttox. My guestion is -Am I more or less likely to getting this syndrome again , or is my body have some immunity to this Syndrome ? No one can tell me yes or no. Please confirm one way or the other. I am 73 years of age.
    James

  3. monotreme1000

    James, I’m sorry, I can’t tell you yes or no either.

    However, Gullain-Barre-Syndrome is an autoimmune disease. It is not a infection. So, there is nothing for you to be immune to. Recurrence of Gullain-Barre-Syndrome is rare, but it does happen. Before taking any vaccine you should speak to a physician. It might be a good idea to talk to one who is a specialist in immunology. If you don’t know one, I would find the nearest medical school and ask to talk to someone there who is most knowledgeable about Gullain-Barre-Syndrome.

    Hope this helps,

    Monotreme

  4. Rainbow Warrior

    More people have died from the ordinary flu then those who have died from H1N1. Many have wondered why WHO said it was a Pandemic.
    From the link above “Study changes Canadian Provinces’s Flu Vaccine plan”

    1. Why did WHO raise the pandemic alert to highest level when less than one thousand people WORLDWIDE have died from causes “associated with h1n1″?
    Pandemic alert level 6 allows martial law and mandatory vaccination. Many if not most of the people who have died had “underlying health problems.”

    *Worldwide, the number of deaths attributed to the flu each year is between 250,000 and 500,000? (Thomas Walkom, The Toronto Star, May 1, 2009).”

    *”…Only 700 people have died from the swine flu world wide in the last year. In the same period, half a million people died of the regular flu, but that isn’t called a pandemic. We are being lied to.” [other reports put the numbers at even less. and then there’s the epidemic of cancer, heart disease and diabetes…]

  5. monotreme1000

    First, some fact checking:

    1. Over 6,000 people have died of the new H1N1 virus throughout the world. Over 1,000 Americans are already dead.

    2. We are at the very beginning of the pandemic, many more people will die soon.

    3. Over 90% of the people who die with seasonal flu are over 65 years old. Over 90% of the people who die of the new H1N1 are under 65 years old. Many of the dead from the new H1N1 are children and pregnant women.

    4. There are no forced vaccinations in the US. Indeed, there is not enough vaccine for everyone who wants it. Some health care workers in some states are required to be vaccinated as a condition of employment to ensure the safety of their patients. But they won’t be forced to be vaccinated.

    5. No-one has declared martial law. Phase 6 did not trigger that event in any country.

    Imo, the WHO waited too long to declare phase 6 (a pandemic). This allowed the virus to spread around the world unchecked. We will all pay a terrible price for their lack of action when it was necessary.

    The conspiracy sites have the situation exactly wrong. The WHO and the CDC didn’t do too much, they did too little. Nothing makes them happier than being criticised for doing too much. It gives them cover for their lack of action.

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