You may have heard that vaccines can trigger Guillain-Barré syndrome in exceedingly rare cases, but did you know that the development of this rare neurological disorder is more strongly linked to viral infections themselves — including influenza? Although Guillain-Barré syndrome is pretty uncommon, it can become life-threatening in some cases. It is, hence, always good to be aware of the possible symptoms so you can promptly seek medical attention if you notice them.
What is Guillain-Barré syndrome?
Guillain-Barré syndrome, also often written simply as Guillain-Barre syndrome and abbreviated to GBS, is an autoimmune neurological disorder in which patients' own immune systems turn on their peripheral nervous systems, causing symptoms like:
- Tingling, "pins and needles" like, sensations that often begin in the legs
- Muscle weakness
- Vision problems
- Trouble speaking and swallowing
- A sudden lack of coordination
- Changes in heart rate or blood pressure
- Sudden problems with bladder control
- Digestive issues
- In severe cases, patients can become paralyzed — since this paralysis can affect the respiratory muscles, making them unable to breathe on their own, this can be fatal
Guillain-Barré syndrome is rare — striking somewhere between 3,000 and 6,000 people in the US each year — and while it may be mild to severe, most people recover from BGS fully, with only an even rarer subset of patients suffering permanent damage. Several types have now been recognized. Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) is a type of GBS in which the symptoms begin within the lower half of the body and then gradually creep upward, while Miller Fisher syndrome (MFS) strikes the eyes first. Acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN) is another type of GBS that is more common in Asia, South America.
Guillain-Barré syndrome is tricky to diagnose, especially in its early stages, and will involve looking at your symptoms and medical history, conducting a physical exam, and ordering tests like a lumber puncture or electromyography. Once the diagnosis has been made, your medical team may recommend immunotherapy, physical therapy, pain relief, and treatment to help prevent the blood clots patients are at a higher risk of if they are paralyzed. Patients who are unable to breathe by themselves will need to be ventilated, and require a feeding tube to meet their nutritional needs.
Can you get Guillain-Barré syndrome from a cold or flu?
In short, yes.
Research has shown that influenza can trigger Guillain-Barré syndrome, but it is important to keep in mind that the trigger for Guillain-Barré syndrome isn't identified in more than half of all cases seen in western countries. We do know that more cases are reported in winter — during flu season — and often after a person had "flu-like symptoms". This means that people had symptoms that can point to influenza, like a sore throat, cough, fever, and muscle aches, but weren't clinically confirmed to have the flu.
Some other common risk factors, which include Campylobacter jejuni (often acquired after eating undercooked or raw meat or following contact with cat or dog feces), cytomegalovirus, the Epstein-Barr virus, and Zika.
While some people also encounter Guillain-Barré syndrome as they recover from a common cold — an entity that can be caused by over 200 different viruses — colds don't top the list when it comes to infections that trigger GBS.
Can a flu vaccine give you Guillain-Barré syndrome?
Vaccines, including the flu shot, seem to occasionally trigger Guillain-Barré syndrome as well. This is something that will be listed on package inserts that accompany flu vaccines, something the CDC acknowledges, and something people considering a flu shot for themselves or their children may be worried about. When you receive a vaccine, you are, after all, deciding to take the proactive step of having something injected into your body to stave off illnesses. In contrast, you may or may not catch a viral infection such as the flu, and your own individual role in that may seem more passive, as it were — leading to an irrational fear of vaccines that trumps the fear you may have about catching influenza.
What people considering a flu shot really want to know is — is the vaccine safe? Context matters:
- Research has shown that the swine flu vaccine given in the 1970s came with an added risk of developing Guillain-Barré syndrome — something that sounds very serious, until you hear that that increase in risk referred to one extra case per 100,000 people.
- Studies on the risk of Guillain-Barré syndrome after receiving annual flu shots for seasonal strains of the flu have consistently demonstrated that any increase in risk is incredibly small — one to two extra cases per million flu shots.
Though Guillain-Barré syndrome is rare, it can't hurt to familiarize yourself with the symptoms — and to let your doctor know right away if you or someone else in your family develops them. The fear of Guillain-Barré syndrome shouldn't, however, be a reason not to get vaccinated against the flu, as you are more likely to develop GBS after catching influenza than following a shot.