she states she can not sleep on the arm/uncomfortable to sleep on it; has a rash on the arm by the injection site and down the arm/She did not expect in the booster dose to have a rash/ that night she noticed the rash; the deltoid is still swollen/ to have her deltoid still swollen/ of course the rash swelled/the deltoid swelled; she expected swelling but did not expect the itching; redness associated with the rash; This spontaneous case was reported by a consumer and describes the occurrence of VACCINATION SITE DISCOMFORT (she states she can not sleep on the arm/uncomfortable to sleep on it), VACCINATION SITE RASH (has a rash on the arm by the injection site and down the arm/She did not expect in the booster dose to have a rash/ that night she noticed the rash), VACCINATION SITE SWELLING (the deltoid is still swollen/ to have her deltoid still swollen/ of course the rash swelled/the deltoid swelled), VACCINATION SITE PRURITUS (she expected swelling but did not expect the itching) and VACCINATION SITE ERYTHEMA (redness associated with the rash) in a 71-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 032F21A, 003A21A and 042L20A) for COVID-19 vaccination.     The patient's past medical history included Heart attack (9 years ago.) in 2012 and Artery dissection (dissected celiac artery) in 2020. Concurrent medical conditions included Heart disease, unspecified.   On 05-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 07-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 04-Nov-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 04-Nov-2021, the patient experienced VACCINATION SITE DISCOMFORT (she states she can not sleep on the arm/uncomfortable to sleep on it), VACCINATION SITE RASH (has a rash on the arm by the injection site and down the arm/She did not expect in the booster dose to have a rash/ that night she noticed the rash), VACCINATION SITE SWELLING (the deltoid is still swollen/ to have her deltoid still swollen/ of course the rash swelled/the deltoid swelled), VACCINATION SITE PRURITUS (she expected swelling but did not expect the itching) and VACCINATION SITE ERYTHEMA (redness associated with the rash). At the time of the report, VACCINATION SITE DISCOMFORT (she states she can not sleep on the arm/uncomfortable to sleep on it), VACCINATION SITE RASH (has a rash on the arm by the injection site and down the arm/She did not expect in the booster dose to have a rash/ that night she noticed the rash), VACCINATION SITE SWELLING (the deltoid is still swollen/ to have her deltoid still swollen/ of course the rash swelled/the deltoid swelled), VACCINATION SITE PRURITUS (she expected swelling but did not expect the itching) and VACCINATION SITE ERYTHEMA (redness associated with the rash) outcome was unknown.            No treatment information was provided. She was on heart medications. This case concerns a 71-year-old female patient with no relevant medical history, who experienced the unexpected events of Vaccination Site Discomfort, Vaccination Site Rash, Vaccination Site Swelling, Vaccination Site Pruritus, and Vaccination Site Erythema. The event occurred the same day after receiving the third dose of mRNA-1273 (Moderna COVID-19 Vaccine). The rechallenge was not applicable since only information about the third dose was disclosed. The events of Vaccination Site Rash, Vaccination Site Swelling, Vaccination Site Pruritus, and Vaccination Site Erythema is consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report.   This case was linked to MOD-2021-378957, MOD-2021-378958.   Most recent FOLLOW-UP information incorporated above includes: On 08-Nov-2021: Follow up includes: reporter information, patient demographics, relevant history, suspect product details and events were added.; Sender's Comments: This case concerns a 71-year-old female patient with no relevant medical history, who experienced the unexpected events of Vaccination Site Discomfort, Vaccination Site Rash, Vaccination Site Swelling, Vaccination Site Pruritus, and Vaccination Site Erythema. The event occurred the same day after receiving the third dose of mRNA-1273 (Moderna COVID-19 Vaccine). The rechallenge was not applicable since only information about the third dose was disclosed. The events of Vaccination Site Rash, Vaccination Site Swelling, Vaccination Site Pruritus, and Vaccination Site Erythema is consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report.