4. Immune-Neurological Responses (Ultra-Rare) — e.g., Guillain-Barré Syndrome
One of the most serious side-effects cited historically is Guillain‑Barré syndrome (GBS) — a rare condition where the body’s immune system attacks nerves, potentially causing paralysis. The 1976 swine-flu vaccination program saw an association with GBS.
Current risk estimates: the CDC states fewer than 1 or 2 cases per million after flu vaccination.
What to know
GBS can result in tingling, weakness in limbs, and potential paralysis. It may require hospitalisation.
The risk of GBS after actual influenza infection is higher than after vaccination.
Why it matters
With healthcare costs high, if a person is hospitalised it may trigger claims through their health insurance plan. If you have a well-rated plan (or use your HSA to offset costs), understanding risk is part of proactive health planning.
What to do
If you experience symptoms like persistent tingling or weakness after a flu vaccine, seek prompt medical evaluation.
Document the timeline (vaccination date, symptom onset) — useful for your medical record or insurance follow-up.
Remember: the risk is extraordinarily small, but knowledge helps.
