On 28 July 2021, Brazil's National Health Surveillance Agency (ANVISA) indicated that it had received 34 reports of suspected cases of Guillain-Barré Syndrome (GBS) following vaccination, of which 27 were associated with the AstraZeneca vaccine, 3 with the Janssen vaccine, and 4 with the CoronaVac vaccine.
In view of these reports, ANVISA requested the inclusion of information on the possible risk of GBS in the product information for the AstraZeneca, Janssen, and CoronaVac vaccines. ANVISA also requested the addition of a warning that people vaccinated with one of these vaccines should seek immediate medical attention if they develop signs and symptoms related to GBS, such as double vision or difficulty moving the eyes, difficulty swallowing, speaking or chewing, coordination problems and unsteadiness, difficulty walking, a tingling sensation in hands and feet, weakness in the extremities, chest, or face, and problems with bladder control and/or bowel function. Healthcare professionals should be alert to the signs and symptoms of GBS, in order to ensure correct diagnosis, initiate care and appropriate supportive treatment, and to rule out other causes.
However, ANVISA continues to recommend the use of all Covid-19 vaccines authorized by the agency, in accordance with the indications described in the corresponding product information sheet, since, to date, the benefits of the vaccines outweigh the risks.