Safety monitoring is of paramount importance for vaccines authorized for 
emergent use (EUA) by the US Food and Drug Administration (FDA) against 
SARS-CoV-2. Mass immunization is an essential tool to end the current pandemic, 
but vaccine surveillance is necessary to identify any potentially associated 
harms. At the same time, probability of temporal bias should be borne in mind 
before making conclusions about causality between the vaccine and an 
attributable undesired effect. We report a case of Guillain-Barré syndrome after 
the first dose of SARS-CoV-2 vaccine and believe this is a temporal, rather than 
causal association.