Guillain-Barré syndrome is thought to be caused by a problem with the immune system, the body's natural defense against illness and infection. New neurologic symptoms is one of the reasons they stopped the J&J vaccines.
Normally the immune system attacks any germs that get into the body. But in people with Guillain-Barré syndrome, something goes wrong and it mistakenly attacks the nerves.
This damages the nerves and stops signals from the brain traveling along with them properly, which can cause problems such as numbness, weakness and pain in the limbs.
It's not clear exactly why this happens. The condition is not passed from person to person and is not inherited.
In the past, the flu vaccine used in the US during a swine flu outbreak in 1976 were linked to an increased risk of Guillain-Barré syndrome.
But research has since found the chances of developing the condition after having a vaccination are extremely small.
For example, a study into the vaccine used during the 2009 swine flu outbreak found that for every million people who had the vaccination, there were fewer than 2 extra cases of Guillain-Barré syndrome.
And evidence suggests that you are far more likely to get Guillain-Barré syndrome from an infection, such as the flu, than the vaccine designed to prevent the infection, such as the flu jab.
Guillain-Barré syndrome (GBS) is a rare disorder where the body’s immune system damages nerve cells, causing muscle weakness and sometimes paralysis. While its cause is not fully understood, the syndrome often follows infection with a virus or bacteria. Each year in the United States, an estimated 3,000 to 6,000 people develop GBS. Most people fully recover from GBS, but some have permanent nerve damage.
In 1976, there was a small increased risk of GBS after swine flu vaccination, which was a special flu vaccine for a potential pandemic strain of flu virus. The National Academy of Medicine, formerly known as the Institute of Medicine, conducted a scientific review of this issue in 2003 and found that people who received the 1976 swine flu vaccine had an increased risk for developing GBS. The increased risk was approximately one additional case of GBS for every 100,000 people who got the swine flu vaccine. Scientists have several theories about the cause, but the exact reason for this link remains unknown.
There have been several studies of the risk of GBS after flu vaccine and CDC monitors for GBS during each flu season. The data on an association between seasonal influenza vaccine and GBS have been variable from season to season. When there has been an increased risk, it has consistently been in the range of 1-2 additional GBS cases per million flu vaccine doses administered.
Studies suggest that it is more likely that a person will get GBS after getting the flu than after vaccination. It is important to keep in mind that severe illness and death are associated with flu, and getting vaccinated is the best way to prevent flu infection and its complications.
