she fell sleep; when she woke up, she could not breath; drug exposure during pregnancy; exposure via breast milk; chest tightness; This spontaneous prospective pregnancy case was reported by a consumer and describes the occurrence of CHEST DISCOMFORT (chest tightness), SOMNOLENCE (she fell sleep), DYSPNOEA (when she woke up, she could not breath), MATERNAL EXPOSURE DURING PREGNANCY (drug exposure during pregnancy) and MATERNAL EXPOSURE DURING BREAST FEEDING (exposure via breast milk) in a 41-year-old female patient who received mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (batch no. 014H22A) for COVID-19 prophylaxis.     Previously administered products included for COVID-19 prophylaxis: MODERNA COVID-19 VACCINE (First Monovalent Booster dose (Dose 3 )) on 22-Nov-2021, MODERNA COVID-19 VACCINE (2nd Primary monovalent dose) and MODERNA COVID-19 VACCINE (First Primary monovalent dose). Past adverse reactions to the above products included No adverse event with MODERNA COVID-19 VACCINE, MODERNA COVID-19 VACCINE and MODERNA COVID-19 VACCINE.    On 21-Nov-2022, the patient received fourth dose of mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (unknown route) 1 dosage form. Last menstrual period and estimated date of delivery were not provided. On 21-Nov-2022, the patient experienced CHEST DISCOMFORT (chest tightness), MATERNAL EXPOSURE DURING PREGNANCY (drug exposure during pregnancy) and MATERNAL EXPOSURE DURING BREAST FEEDING (exposure via breast milk). On an unknown date, the patient experienced SOMNOLENCE (she fell sleep) and DYSPNOEA (when she woke up, she could not breath). On 21-Nov-2022, CHEST DISCOMFORT (chest tightness), MATERNAL EXPOSURE DURING PREGNANCY (drug exposure during pregnancy) and MATERNAL EXPOSURE DURING BREAST FEEDING (exposure via breast milk) had resolved. At the time of the report, SOMNOLENCE (she fell sleep) and DYSPNOEA (when she woke up, she could not breath) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Chest X-ray: X-Ray of lungs was normal. On an unknown date, Electrocardiogram: EKG ruled out Myocarditis. On an unknown date, Laboratory test: All tests were normal.     For mRNA-1273 BIVALENT .222 (MODERNA COVID-19 VACCINE, BIVALENT (ORIGINAL AND OMICRON BA.4/BA.5)) (Unknown), the reporter did not provide any causality assessments.   No concomitant and treatment medications were reported. It was reported that after the first 3 shots, patient did not have any side effects. Patient stated that within 6 hours after vaccination  fell sleep, and when patient woke up, she could not breath and she had chest tightness. Patient ended up in the emergency room. They did not prescribe anything. They just watched patient for a few hours and discharged when symptoms went away.  Company comment This spontaneous case concerns a 41-year-old female patient, with no relevant medical history reported, who experienced the unexpected non-serious events chest discomfort, somnolence, dyspnoea. the non-serious unexpected events of maternal exposure during pregnancy and maternal exposure during breast feeding were also reported. The patient received all four doses of mRNA-1273. After the first three shots, she did not have any side effects. She stated that within six hours after vaccination with the fourth dose of mRNA-1273.222 (BA.4/BA.5) (MODERNA COVID-19 VACCINE, BIVALENT ORIGINAL AND OMICRON BA.4/BA.5), she fell sleep, and when she woke up, she could not breathe and had chest tightness. She ended up in the Emergency Room. An Electrocardiogram was performed and ruled out Myocarditis, X-Ray of lungs was normal. All other tests were normal. They did not prescribe anything. She was on observation for a few hours and discharged her when symptoms went away. It was unclear whether the patient was pregnant and breastfeeding at the time of the fourth dose or during prior vaccinations. No further clinical information such as gestational age, pregnancy outcome was available for review. The benefit-risk relationship of mRNA-1273.222 (BA.4/BA.5) vaccine is not affected by this report.   Reporter did not allow further contact; Sender's Comments: This spontaneous case concerns a 41-year-old female patient, with no relevant medical history reported, who experienced the unexpected non-serious events chest discomfort, somnolence, dyspnoea. the non-serious unexpected events of maternal exposure during pregnancy and maternal exposure during breast feeding were also reported. The patient received all four doses of mRNA-1273. After the first three shots, she did not have any side effects. She stated that within six hours after vaccination with the fourth dose of mRNA-1273.222 (BA.4/BA.5) (MODERNA COVID-19 VACCINE, BIVALENT ORIGINAL AND OMICRON BA.4/BA.5), she fell sleep, and when she woke up, she could not breathe and had chest tightness. She ended up in the Emergency Room. An Electrocardiogram was performed and ruled out Myocarditis, X-Ray of lungs was normal. All other tests were normal. They did not prescribe anything. She was on observation for a few hours and discharged her when symptoms went away. It was unclear whether the patient was pregnant and breastfeeding at the time of the fourth dose or during prior vaccinations. No further clinical information such as gestational age, pregnancy outcome was available for review. The benefit-risk relationship of mRNA-1273.222 (BA.4/BA.5) vaccine is not affected by this report.