I KNOW I AM EXPERIENCING GUILLAIN-BARRE SYMPTOMS; TINGLING IN TOES, RIGHT FOOT; SHOCKS IN TOES, RIGHT FOOT; This spontaneous report received from a patient concerned a 40 year old female. The patient's weight, height, and medical history were not reported. Patient stated she had no pre-existing conditions.  The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, intramuscular, batch number: UNKNOWN) dose and anatomical vaccination site were not reported, administered on 31-MAR-2021 for prophylactic vaccination. The batch numbers was not reported and has been requested. No concomitant medications were reported.  On 01-APR-2021, the patient experienced sharp tingling and shocks in toes on right foot. The tingling started the day after the vaccine and persisted daily for a month and a half; then, it subsided every other week. It has been over 90 days since the patient was vaccinated, and was still feeling these tingles. The patient did not have any spots on her toes. After reading the recent news release about Guillain-Barre syndrome as a side effect of the vaccine and researching the symptoms, the patient reported that she thinks this is what she has been experiencing. According to the patient, the patient's physician has not been very helpful in diagnosing the source saying they didn't have any information about possible side effects, hence the patient was reaching out because "I know I am experiencing Guillain-Barre symptoms" The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient had not recovered from events ("I know I am experiencing Guillain-Barre symptoms", tingling in toes, right foot and shocks in toes, right foot). This report was serious (Other Medically Important Condition).; Sender's Comments: V0: This spontaneous report received from a patient concerned a 40-year-old woman who experienced tingling, "shocks," and other neurologic symptoms that she believed were Guillain-Barre syndrome. Patient stated she had no pre-existing conditions. No concomitant medications were reported. On day 1, the patient experienced sharp tingling and shocks in toes on right foot. The tingling started the day after the vaccine and persisted daily for a month and a half; then, it subsided every other week. It has been over 90 days since the patient was vaccinated, and was still feeling these "tingles." The patient did not have any spots on her toes. After reading the recent news release about Guillain-Barre syndrome as a side effect of the vaccine and researching the symptoms, the patient reported that she thinks this is what she has been experiencing. According to the patient, the patient's physician has not been very helpful in diagnosing the source saying they didn't have any information about possible side effects, hence the patient was reaching out because "I know I am experiencing Guillain-Barre symptoms". There was no specific information reported on diagnostics, labs, or treatment. Information regarding other potential etiologies was insufficient, and the occurrence of concern for GBS could represent background incidence of such events in the general population. Considering the temporal relationship, the event is assessed to have an indeterminate relationship with vaccination.