Author Response: SARS-CoV-2 Vaccination Safety in Guillain-Barré Syndrome, Chronic Inflammatory Demyelinating Polyneuropathy, and Multifocal Motor Neuropathy

We appreciate the comment by Dr. Harth concerning our recent prospective study that investigated the risk of recurrences of Guillain-Barré syndrome (GBS) and exacerbations of chronic inflammatory demyelinating polyneuropathy (CIDP) or multifocal motor neuropathy after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination.¹ We regret that our colleague experienced both brachial plexopathy and dysautonomia after a third coronavirus disease vaccination. Without the presence of other antecedent events, vaccination cannot be ruled out as a potential cause.

Several patients in our study shared similar concerns when obtaining SARS-CoV-2 vaccination, in particular when GBS or CIDP developed after another vaccination (e.g., against flu). Our study design is unsuitable to exclude the possibility of a causal relationship, leaving patients with experiences similar to Dr. Harth's in doubt. The chance of developing a serious infection should be weighed against the chance of developing a new episode of neurologic disease after (re)vaccination.

Another study described that the risk of developing neurologic complications is greater after SARS-CoV-2 infection than after SARS-CoV-2 vaccination.² Only 19 patients in our study were previously diagnosed with GBS or CIDP after a vaccination, but also in these patients we found no reason for concern. We agree that robust data on potential causes of neurologic complications are needed and emphasize that open communication with patients about their concerns remains important.