Leg Paralysis After Flu Shot Requires Immediate Emergency Evaluation
No, it is absolutely NOT normal for legs to stop moving after a flu shot, and this requires immediate emergency medical evaluation to rule out Guillain-Barré syndrome or other serious neurological complications. 1
Why This Is a Medical Emergency
Rapidly ascending weakness or paralysis following vaccination can indicate Guillain-Barré syndrome (GBS), a rare but serious neurological complication that was associated with the 1976 swine influenza vaccine at a rate of approximately 10 cases per million vaccinated persons 1
Immediate medical attention is necessary when symptoms include rapidly ascending weakness or paralysis, as delays in diagnosis and treatment of GBS can affect outcomes 2
While neurological complications following influenza vaccination are extremely rare, they can include GBS, cranial nerve palsies, and peripheral neuropathies 2
What You Should Do Right Now
Seek emergency medical care immediately - do not wait to see if symptoms improve 2
The evaluation should focus on:
Important Context About Vaccine Safety
The vast majority of flu vaccine reactions are mild and localized, affecting 10-64% of patients with soreness at the injection site lasting up to 2 days 1, 3
Common systemic reactions include fever, malaise, and myalgia beginning 6-12 hours after vaccination and lasting 1-2 days - these are NOT the same as paralysis 1
Peripheral nerve injuries can rarely occur from vaccination, such as the case report of radial nerve motor palsy developing 12-16 hours post-vaccination, though this affected the arm, not legs 4
Critical Pitfall to Avoid
Do not assume all post-vaccination symptoms are normal vaccine reactions - coincidental serious illnesses can occur after vaccination that are unrelated to the vaccine itself 1, 3
The Institute of Medicine recommends reporting potential neurologic complications following vaccination, even though no definitive causal relationship has been established for most neurologic disorders 2