ACUTE HYPOXEMIC RESPIRATORY FAILURE; RIGHT HIP INTERTROCHANTERIC PROXIMAL FEMUR FRACTURE; CLOSED FRACTURE OF MULTIPLE RIBS OF RIGHT SIDE; CLOSED FRACTURE OF LEFT PROXIMAL HUMERUS; This 73 -year-old,  male subject was participating in Study and experienced right hip intertrochanteric proximal femur fracture, closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure.   The subject's medical history, as provided by the investigator, included focused seizures, hypertension, stroke, and moderate lower back pain. Concomitant medications included lamotrigine, metoprolol, acetylsalicylic acid, multivitamin NOS, and terbinafine 1%.   The subject was randomized to receive intramuscular Placebo (dosed on 17 Sep 2020 and 19 Oct 2020) and was unblinded on 26 Jan 2021. The subject consented to receive mRNA-1273 for SARS-CoV-2 vaccination after being unblinded and, prior to event onset, the subject received mRNA-1273 (Dose 3, booster) SARS-CoV-2 vaccination on 03 Dec 2021, approximately 4 months 26 days before onset of the event.  On 28 Apr 2022, the subject experienced right hip intertrochanteric proximal femur fracture. The subject's girlfriends notified the site that the subject had been hospitalized due to a broken hip. Open reduction and internal fixation was performed  On 29 Apr 2022, the subject experienced acute hypoxemic respiratory failure likely due to chronic obstructive pulmonary disease (COPD) and fluid overload from intravenous fluids. Treatment medications included furosemide, antibiotics, and a nebulizer. He improved after three days.   On 06 May 2022, the subject was discharged from the hospital to a skilled nursing facility. He was discharged on 4 liter home oxygen.  On 11 May 2022, the subject experienced closed fracture of multiple ribs of right side and closed fracture of left proximal humerus. It was reported the subject missed a step which caused him to fall. The subject spent two days in the intensive care unit. He underwent intermedullary nailing of his left humerus and rib pain was controlled with oral pain medications.   On 16 May 2022, the subject was discharged from the hospital.  The subject received all scheduled doses of study drug prior to the event; therefore, action taken with study drug in response to the event was not applicable.  The events, right hip intertrochanteric proximal femur fracture and closed fracture of multiple ribs of right side, were reported as resolving.  The event, acute hypoxemic respiratory failure, was reported as resolved on 02 May 2022.  The event, closed fracture of left proximal humerus, was reported as resolved on 13 May 2022.  The investigator assessed the event, right intertrochanteric proximal femur fracture, as not related to study drug and not related to study procedure.  Investigator causality to closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure was not provided.  Company comment: This case concerns a 73 -year-old, male subject with a medical history of focused seizures, hypertension, stroke, and moderate lower back pain, who experienced the unlisted events of right hip intertrochanteric proximal femur fracture, closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure. The event right hip intertrochanteric proximal femur fracture occurred 1 year 3 months 1 day after the first dose of mRNA-1273 administration and 4 months 26 days after the third and booster dose; the event acute hypoxemic respiratory failure occurred 1 year 3 months 2 days after the first dose of mRNA-1273 administration and 4 months 27 days after the third and booster dose, and the events closed fracture of multiple ribs of right side and closed fracture of left proximal humerus occurred 1 year 3 months 14 days after the first dose of mRNA-1273 administration, and 5 months 9 days after the third and booster dose. The events, right hip intertrochanteric proximal femur fracture and closed fracture of multiple ribs of right side, were reported as resolving, and the events acute hypoxemic respiratory failure and closed fracture of left proximal humerus, were reported as resolved. The event, right intertrochanteric proximal femur fracture was considered as not related to study drug in agreement with the investigator based on the nature of the event. The Investigator´s causality was not provided for the events closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure. The sponsor considers the events closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure as not related to IP; the events closed fracture of multiple ribs of right side and closed fracture of left proximal humerus were accidental in nature as these were secondary to a fall and the event acute hypoxemic respiratory failure might be explained by fluid overload from intravenous fluids in the context of a subject with chronic obstructive pulmonary disease (as reported). Additional information was requested.; Reporter's Comments: This case concerns a 73 -year-old, male subject with a medical history of focused seizures, hypertension, stroke, and moderate lower back pain, who experienced the unlisted events of right hip intertrochanteric proximal femur fracture, closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure. The event right hip intertrochanteric proximal femur fracture occurred 1 year 3 months 1 day after the first dose of mRNA-1273 administration and 4 months 26 days after the third and booster dose; the event acute hypoxemic respiratory failure occurred 1 year 3 months 2 days after the first dose of mRNA-1273 administration and 4 months 27 days after the third and booster dose, and the events closed fracture of multiple ribs of right side and closed fracture of left proximal humerus occurred 1 year 3 months 14 days after the first dose of mRNA-1273 administration, and 5 months 9 days after the third and booster dose. The events, right hip intertrochanteric proximal femur fracture and closed fracture of multiple ribs of right side, were reported as resolving, and the events acute hypoxemic respiratory failure and closed fracture of left proximal humerus, were reported as resolved. The event, right intertrochanteric proximal femur fracture was considered as not related to study drug in agreement with the investigator based on the nature of the event. The Investigator´s causality was not provided for the events closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure. The sponsor considers the events closed fracture of multiple ribs of right side, closed fracture of left proximal humerus, and acute hypoxemic respiratory failure as not related to IP; the events closed fracture of multiple ribs of right side and closed fracture of left proximal humerus were accidental in nature as these were secondary to a fall and the event acute hypoxemic respiratory failure might be explained by fluid overload from intravenous fluids in the context of a subject with chronic obstructive pulmonary disease (as reported). Additional information was requested.