severe deplicition of breast milk; Soreness to left arm; severe body and joint aches; severe body and joint aches; slight palpitations; Maternal exposure during breast feeding; This spontaneous case was reported by a nurse and describes the occurrence of PALPITATIONS (slight palpitations), SUPPRESSED LACTATION (severe deplicition of breast milk), PAIN IN EXTREMITY (Soreness to left arm), ARTHRALGIA (severe body and joint aches) and MYALGIA (severe body and joint aches) in a 33-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 003F21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Pre-eclampsia in March 2021. Concurrent medical conditions included Pollen allergy.    On 27-Oct-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-Oct-2021, the patient experienced MATERNAL EXPOSURE DURING BREAST FEEDING (Maternal exposure during breast feeding). On 28-Oct-2021, the patient experienced PALPITATIONS (slight palpitations), PAIN IN EXTREMITY (Soreness to left arm), ARTHRALGIA (severe body and joint aches) and MYALGIA (severe body and joint aches). On 29-Oct-2021 at 6:00 PM, the patient experienced SUPPRESSED LACTATION (severe deplicition of breast milk). On 27-Oct-2021, MATERNAL EXPOSURE DURING BREAST FEEDING (Maternal exposure during breast feeding) had resolved. On 01-Nov-2021, PALPITATIONS (slight palpitations), ARTHRALGIA (severe body and joint aches) and MYALGIA (severe body and joint aches) had resolved. At the time of the report, SUPPRESSED LACTATION (severe deplicition of breast milk) and PAIN IN EXTREMITY (Soreness to left arm) was resolving.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered PALPITATIONS (slight palpitations), ARTHRALGIA (severe body and joint aches) and MYALGIA (severe body and joint aches) to be possibly related. No further causality assessments were provided for SUPPRESSED LACTATION (severe deplicition of breast milk), PAIN IN EXTREMITY (Soreness to left arm) and MATERNAL EXPOSURE DURING BREAST FEEDING (Maternal exposure during breast feeding).    No concomitant medication was reported It was reported that the patient had a medical consultation on 03-Nov-2021 and currently on the treatment regime with notable improvement in condition.  This case concerns a 33-year-old, female patient with no relevant medical history reported, with Maternal exposure during breast feeding, who experienced non-serious events including Suppressed lactation with associated events in the child (dehydration, reported in a separate case). The exposure occurred with the second dose of mRNA-1273 vaccine. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2021-358025 (Parent-Child Link). This case was linked to MOD-2021-357203 (Patient Link).   See case MOD-2021-358025 for details regarding the child case.  Most recent FOLLOW-UP information incorporated above includes: On 15-Nov-2021: Follow up information was received on 15-Nov-2021 and contains no new information; Sender's Comments: This case concerns a 33-year-old, female patient with no relevant medical history reported, with Maternal exposure during breast feeding, who experienced non-serious events including Suppressed lactation with associated events in the child (dehydration, reported in a separate case). The exposure occurred with the second dose of mRNA-1273 vaccine. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.