[Case report of Guillain-Barré Syndrome after COVID BNT162b2 mRNA vaccine].

Introduction: Guillain-Barré syndrome (GBS) is a rare immune disorder that affects peripheral nerves and the cause is not known completely, but it is associated with infections by viruses or bacteria.

Case Report: We report the case of a 23-year-old male patient, a health student, who start 24 hours after received the second dose of COVID-19 vaccine, with proximal weakness of the right upper limb, later on the left side with descending and distal progression.

Discussion: GBS cases related to COVID-19 vaccines have been published, the most common being BNT162b2, which is mRNA, there are also cases published after the AZD1222 (ChAdOx1) vaccine, which is a non-replicating viral vector. The incidence of GBS is estimated at 0.43 per 100.00 doses applied, under registered national incidence of 1.1-1.8 per 100,000 persons per year.

Conclusions: It is important to mention that although GBS can occur after vaccination against COVID-19, this incidence is much lower than which occurs in the community in Mexico associated with other diseases, considering more common the presence of cases related to infectious gastrointestinal diseases.