Guillain-Barré syndrome (GBS) is not contagious. You cannot catch it from another person through touch, coughing, shared food, or any other form of contact. GBS is an autoimmune condition, meaning it’s caused by your own immune system attacking your peripheral nerves. It affects roughly 1 to 2 people per 100,000 each year, and the risk increases with age, ranging from about 0.6 cases per 100,000 in children under 10 to 2.7 per 100,000 in adults over 80.
Why GBS Can’t Spread Between People
GBS isn’t caused by a germ that moves from one person to another. It’s a misfired immune response. After fighting off a routine infection, your immune system sometimes keeps attacking, but instead of targeting bacteria or viruses, it turns on the protective coating around your peripheral nerves. This happens because certain molecules on the surface of common bacteria and viruses look structurally similar to molecules found on nerve cells, a process called molecular mimicry. Your immune system can’t tell the difference, so it produces antibodies that damage your own nerves.
The antibodies target specific fatty molecules concentrated at critical gaps along nerve fibers. These gaps are essential for transmitting electrical signals quickly through your body. When they’re damaged, signals slow down or stop entirely, which is why GBS causes weakness, numbness, and sometimes paralysis. The damage is entirely self-inflicted by the immune system, not caused by any pathogen living in the nerves.
The Infections That Trigger GBS
About two out of three people who develop GBS had diarrhea or a respiratory illness in the weeks before symptoms began. The infection itself is usually mild and unremarkable. It’s the immune response that follows, not the infection, that causes the problem. The most common triggers include:
- Campylobacter bacteria: The single most common trigger in the United States, typically causing a brief bout of food poisoning. The CDC estimates Campylobacter is responsible for 5 to 41% of GBS cases, yet only 0.2 to 1.7 out of every 1,000 Campylobacter infections actually leads to GBS.
- Influenza and other respiratory viruses: Common flu infections occasionally precede GBS.
- Cytomegalovirus and Epstein-Barr virus: Both are extremely widespread viruses that most people encounter at some point in life.
- Zika virus: Linked to GBS outbreaks in regions where the virus has spread.
- SARS-CoV-2: COVID-19 infection has been associated with a roughly threefold increased risk of GBS within 42 days of illness.
These infections are common. Millions of people get them every year and never develop GBS. The syndrome appears to require a specific, unlucky combination of the infection and an individual’s immune response. Researchers still don’t fully understand why one person’s immune system makes this mistake while another’s doesn’t.
What About Family Members?
If someone in your household has GBS, you are not at risk of developing it from being around them. The condition is not inherited and does not cluster in families through any contagious mechanism. That said, if the person with GBS recently had a stomach bug or respiratory infection, the underlying infection could theoretically be contagious through normal routes (contaminated food, airborne droplets). But even if you caught the same infection, your chance of it triggering GBS would be extremely small. Standard hygiene, like handwashing after using the bathroom and covering coughs, is all that’s needed.
A Note on GBS vs. Group B Strep
The abbreviation “GBS” can cause confusion because it’s also used for Group B Streptococcus, a completely different condition. Group B Strep is a bacterium that naturally lives in the body of many healthy adults and can be passed to newborns during birth. Guillain-Barré syndrome has nothing to do with this bacterium. If your question is specifically about Group B Strep and whether it’s contagious, that’s a separate topic with different answers. This article covers Guillain-Barré syndrome only.
How GBS Symptoms Develop
GBS typically starts with tingling and weakness in the feet and legs that moves upward over hours to days. Some people first notice it in the arms or face. The weakness can progress to full paralysis in severe cases, and it sometimes affects the muscles needed for breathing, which requires emergency medical support. Most people reach their weakest point within two to four weeks of the first symptom.
The connection to a prior illness is often the key clue for diagnosis. If you developed sudden, spreading weakness after a recent infection, that pattern is highly characteristic of GBS.
Treatment and What Recovery Looks Like
There is no cure for GBS, but two main treatments can shorten the illness and reduce its severity. One involves receiving donated antibodies through an IV to help calm the immune system. The other filters the blood to physically remove the harmful antibodies attacking the nerves. A large meta-analysis found that both treatments produce similar outcomes in terms of recovery, though patients tend to tolerate the antibody infusion better and are less likely to need to stop treatment early.
Recovery varies widely. Some people are back on their feet within weeks. Others need months of rehabilitation to regain strength, and a small percentage are left with lasting weakness or fatigue. In one study, 53% of patients treated with antibody infusions had improved by at least one functional grade after four weeks. Age, severity at the worst point, and how quickly treatment starts all influence the trajectory. Most people do recover substantially, but the process is often slower than expected.
COVID-19, Vaccines, and GBS Risk
A large multinational study examined GBS risk after both COVID-19 infection and vaccination. COVID-19 infection itself was associated with a 3.35-fold increased risk of GBS within 42 days. One specific adenoviral vector vaccine (AstraZeneca’s Vaxzevria/Covishield) showed a similarly elevated risk, at about 3.1 times the baseline. However, the mRNA vaccines (like those from Pfizer) were actually associated with a lower risk of GBS compared to baseline, as were inactivated virus vaccines. For most people, the net effect of vaccination was protective, since avoiding a COVID-19 infection itself reduces the much larger GBS risk that comes with the disease.