🟢 Note: This article is written for the general public, using simple and accessible language.
Shingles (zona) is a painful condition caused by reactivation of the varicella-zoster virus. To reduce this risk, the recombinant shingles vaccine Shingrix has been widely recommended, especially for adults over 50. However, concerns have emerged about a potential association between Shingrix and Guillain–Barré syndrome (GBS), a rare but serious neurological disorder. This article reviews the latest scientific evidence, risk estimates, and clinical recommendations.
Can the Shingles Vaccine (Shingrix) Cause Guillain–Barré Syndrome (GBS)?
Short answer: There have been very rare reports and some observational signals of an increased risk of Guillain–Barré syndrome in the weeks after Shingrix, but the absolute risk is extremely small. Health agencies include warnings in the Shingrix prescribing information and recommend weighing benefits and risks, especially in older adults and people with specific concerns.
What is Guillain–Barré Syndrome (GBS)?
Guillain–Barré syndrome is an acute autoimmune neuropathy in which the body’s immune system attacks peripheral nerves, causing progressive weakness, sensory symptoms, and in severe cases respiratory failure. It most commonly occurs after infections (Campylobacter jejuni, cytomegalovirus, etc.) and — much less commonly — after some vaccinations. Early recognition and prompt treatment (IVIG or plasmapheresis) improve outcomes.
What is Shingrix?
Shingrix (recombinant zoster vaccine, RZV) is a non-live, adjuvanted vaccine from GSK, used to prevent shingles (herpes zoster) and post-herpetic neuralgia in adults 50+ and in adults 18+ with immunocompromise. Shingrix is a two-dose series given intramuscularly.
What do regulators and major public health bodies say?
FDA (United States): Based on post-marketing observational data, the FDA required a warning about Guillain–Barré syndrome to be included in Shingrix prescribing information (observed increased risk in the 42 days post-vaccination in certain studies).
- CDC: Notes that GBS has been reported very rarely after Shingrix and that there is also a very small increased risk of GBS after shingles itself; they recommend discussing concerns with clinicians.
- TGA (Australia): Reports an estimated ~3 excess cases of GBS per million doses in one post-marketing observational study in persons ≥65 years during the 42-day risk window, and states evidence is insufficient to prove causality.
These official statements reflect caution: regulators flagged a rare safety signal, added warnings, and continue to emphasize that the absolute risk is very low while shingles causes substantial morbidity that vaccination prevents.
What does the scientific literature show?
A 2021 self-controlled / observational assessment found a small increase in GBS risk following recombinant zoster vaccine in older adults, which contributed to regulatory warnings. PubMed
Multiple post-marketing surveillance reports and several recent case reports (2024–2025) document individual GBS cases within days–weeks after Shingrix; case reports do not prove causation but contribute to signal detection and hypothesis generation.
- Systematic/global analyses of vaccine-associated GBS show that vaccines overall are a rare cause among many triggers, and background rates plus surveillance biases must be considered. Large observational studies help quantify excess risk per million doses rather than rely on anecdote.
How big is the risk ?
Regulatory and observational estimates put the excess risk at approximately a few cases per million doses in older populations within the first 6 weeks after vaccination (estimates like ~3 excess cases per million doses have been reported). That means for every million doses administered, there might be a handful more GBS cases than expected — while the vaccine prevents thousands of shingles cases and many complications.
Does this prove Shingrix causes GBS?
No — a causal relationship has not been definitively proven. Observational studies can detect small increases in risk, but they may be affected by confounders, reporting biases, and background incidence. Regulators added warnings because an increased rate was observed in some studies, but they emphasize that the evidence is insufficient to definitively establish causation.
Who should be concerned or consider delaying vaccination?
People with a recent history of GBS (within months): discuss with your physician. For some vaccines, a recent history of GBS can be a precaution — individual assessment is required.
People with active neurological symptoms: delay vaccination until stabilized and consult a neurologist.
General population (≥50 years): the benefit-risk ratio generally favors vaccination because shingles and post-herpetic neuralgia cause substantial morbidity and the excess GBS risk is extremely small.
Always discuss personal risks (age, immunosuppression, co-morbidities) with your doctor. Official prescribing information should guide clinicians.
Signs and timeline: what symptoms after vaccination are concerning?
If someone develops any of the following within days to 6 weeks of vaccination, they should seek urgent medical attention and neurological evaluation:
Progressive weakness (legs first, then arms), difficulty walking
Numbness or tingling that progresses rapidly
Difficulty breathing or swallowing (emergency)
Rapidly progressive balance problems or loss of reflexes
Early neurology referral and treatment (IVIG or plasmapheresis) improve recovery chances.
Practical takeaways for clinicians and patients
The signal is real but rare: regulators updated labels; observational studies estimated a few extra GBS cases per million doses in specific analyses.
- For most patients (older adults, immunocompromised at risk of shingles), the benefits outweigh the tiny risk. Vaccination prevents shingles, severe pain, and complications that impair quality of life.
Document informed consent for patients with questions; explain the absolute numbers and that surveillance is ongoing.
Report suspected post-vaccination GBS to your country’s vaccine safety surveillance system (e.g., VAERS, local pharmacovigilance).
FAQ
Q: Has the FDA warned that Shingrix can cause Guillain–Barré syndrome?
A: The FDA required that a warning about GBS be included in the Shingrix prescribing information after post-marketing observational data showed an increased rate in a 42-day window; however, causality remains unproven.
Q: How common is GBS after Shingrix?
A: Observational estimates indicate only a few extra cases per million doses (for example ~3 excess cases per million in one older-adult study), so the absolute risk is extremely low.
Q: What should I do if I have symptoms after Shingrix?
A: Seek urgent medical care for progressive weakness, difficulty breathing, or rapidly worsening numbness — early treatment improves outcomes.
References
- FDA — SHINGRIX prescribing information and FDA safety communication.
- TGA (Australia) safety update: Shingrix and very rare risk of Guillain–Barré syndrome; estimate ~3 excess cases per million doses in one study.
- CDC guidance and vaccine pages (Shingles vaccine overview; notes about very rare GBS reports).
- Goud R. et al., Risk of Guillain-Barré Syndrome Following Recombinant Zoster Vaccine — observational analyses.
- Recent case reports and 2024–2025 post-marketing safety surveillance publications documenting individual GBS cases after Shingrix.