Convulsions/Seizures (SZ); This literature-non-study case was reported in a literature article and describes the occurrence of SEIZURE (Convulsions/Seizures (SZ)) in a  patient of an unknown age and gender who received mRNA-1273 (Spikevax) for COVID-19 prophylaxis.        No Medical History information was reported.    On an unknown date, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date, the patient experienced SEIZURE (Convulsions/Seizures (SZ)) (seriousness criteria hospitalization and medically significant). At the time of the report, SEIZURE (Convulsions/Seizures (SZ)) outcome was unknown.        The action taken with mRNA-1273 (Spikevax) (Unknown) was unknown.   For mRNA-1273 (Spikevax) (Unknown), the reporter did not provide any causality assessments.   This case refers to patient no 2 of 2 patients who experienced the seizure after first dose of mRNA-1273 vaccine.  Concomitant and treatment medications were not reported.  This study described simultaneous vaccination (SV) with primary series COVID-19 vaccines and assess 23 pre-specified health outcomes following SV among persons aged greater than or equal to 5 years in the Vaccine Safety Datalink (VSD). from December 11, 2020-May 21, 2022. Analyses assessed frequency of SV.  Statistically significant elevated RRs were observed for convulsions/seizures (2.78; 95 % CI, 1.107.06) in the All SV" group following dose 1.  All Simultaneous Vaccines" group for both appendicitis and convulsions/seizures in the 121 days following COVID-19 vaccine dose 1 among COVID 19 vaccinees receiving simultaneous vaccination vs. COVID-19 vaccinees not receiving simultaneous vaccination.  The adjusted rate ratio was significantly elevated for convulsions/seizures following COVID-19 vaccine dose 1 (age range: 8-44 years), the incidence rate among those who received simultaneous vaccination with COVID-19 vaccine was 0.87 per 10,000 (8.7 per 100,000), well below the background incidence rate.  Authors concluded that overall, the combined pre-specified health outcomes observed among persons who received simultaneous vaccines with COVID-19 vaccine were also rare and not at a statistically significantly different rate compared with those who did not receive simultaneous vaccination with the COVID-19 vaccine. Statistically significant adjusted rate ratios were observed for some individual outcomes (appendicitis, convulsions/seizures, and Bell's palsy), but the number of cases was small, there was no adjustment for multiple testing, and the possible effect of residual unmeasured confounding in these analyses may have contributed to these findings.   This case was linked to US-MODERNATX, INC.-MOD-2023-731103 (Linked Report).  Company Comment: This is a literature non-study case concerning a patient of unknown age and gender, with no reported medical history, who experienced the serious (due to medically significant and hospitalization) unexpected, AESI of Seizure, which occurred within 42 days after the first dose of mRNA-1273 vaccine. The outcome was not reported. No further clinical information was available for medical review. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 30-Jun-2023: Follow-up received by safety on 30-Jun-2023 has an email with full text article and contains significant information. Case validity, reporter's information, literature information, suspect vaccine details, event details and data were updated.; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-731103:Master case