Following the 4th dose she had vomiting and felt a little foggy; sore arm, fever, headaches, aches, and "all that; sore arm, fever, headaches, aches, and "all that; Following the 4th dose she had vomiting and felt a little foggy; sore arm, fever, headaches, aches, and "all that; sore arm, fever, headaches, aches, and "all that; This spontaneous case was reported by an other health care professional and describes the occurrence of BRAIN FOG (Following the 4th dose she had vomiting and felt a little foggy), PAIN IN EXTREMITY (sore arm, fever, headaches, aches, and "all that), PAIN (sore arm, fever, headaches, aches, and "all that), VOMITING (Following the 4th dose she had vomiting and felt a little foggy) and PYREXIA (sore arm, fever, headaches, aches, and "all that) in an elderly female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 027L21A, 011D21A, 029K20A and 039K20A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 26-Dec-2020, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 26-Jan-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 18-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 04-Apr-2022, received fourth dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced BRAIN FOG (Following the 4th dose she had vomiting and felt a little foggy), PAIN IN EXTREMITY (sore arm, fever, headaches, aches, and "all that), PAIN (sore arm, fever, headaches, aches, and "all that), VOMITING (Following the 4th dose she had vomiting and felt a little foggy), PYREXIA (sore arm, fever, headaches, aches, and "all that) and HEADACHE (sore arm, fever, headaches, aches, and "all that). At the time of the report, BRAIN FOG (Following the 4th dose she had vomiting and felt a little foggy), PAIN IN EXTREMITY (sore arm, fever, headaches, aches, and "all that), PAIN (sore arm, fever, headaches, aches, and "all that), VOMITING (Following the 4th dose she had vomiting and felt a little foggy), PYREXIA (sore arm, fever, headaches, aches, and "all that) and HEADACHE (sore arm, fever, headaches, aches, and "all that) outcome was unknown.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Concomitant product use was not provided by the reporter.  The patient had no symptoms following the first 2 doses. After the third and fourth dose she had a sore arm, fever, headaches, aches, and "all that." Following the fourth dose she had vomiting and felt a little foggy.  It was reported that patient had received a flu shot somewhat recently but not within 4 weeks of any of the COVID-19 vaccines. She had never taken any Pfizer vaccines.    Treatment information was not provided.   This case was linked to US-MODERNATX, INC.-MOD-2023-737351 (Linked Report).; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-737351:Bivalent dose case