Exacerbation of COPD; Acute hypoxic respiratory failure; This literature-non-study case was reported in a literature article and describes the occurrence of CHRONIC OBSTRUCTIVE PULMONARY DISEASE (Exacerbation of COPD) and ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure) in an elderly male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.   Concurrent medical conditions included Restrictive pulmonary disease, Lung disease obstructive and Shortness of breath.   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced CHRONIC OBSTRUCTIVE PULMONARY DISEASE (Exacerbation of COPD) (seriousness criterion hospitalization) and ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure) (seriousness criteria hospitalization and medically significant). The patient was treated with ALBUTEROL SULFATE for COPD exacerbation, at an unspecified dose and frequency. At the time of the report, CHRONIC OBSTRUCTIVE PULMONARY DISEASE (Exacerbation of COPD) had not resolved and ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Influenza virus test: negative (Negative) Negative. On an unknown date, PO2: po2 was noted to be only 46 PO2 was noted to be only 46. On an unknown date, SARS-CoV-2 test: negative (Negative) negative.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered CHRONIC OBSTRUCTIVE PULMONARY DISEASE (Exacerbation of COPD) and ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure) to be possibly related.    At baseline, his breathing was well controlled, and he had compliant with daily Fluticasone/salmeterol and tiotropium, albuterol as needed, and supplemental oxygen at 2-3L per minute as needed on the day of admission. Noted worsening of his breathing throughout the afternoon as well as the development of a productive cough. As prepared for bed, noticed worsening shortness of breath and increasing mucus production, at which time, he self-administered an albuterol treatment and applied his nasal cannula. His symptoms did not improved. At hospital, he was still seen to be hypoxic even with increased oxygen low rates. He was placed on noninvasive positive-pressure ventilation, started on steroids, scheduled breathing treatment and admitted for acute hypoxic respiratory failure.  This case concerns an elderly male patient with medical history of chronic obstructive/restrictive pulmonary disease, who experienced the unexpected events of COPD exacerbation and Acute hypoxic respiratory failure, which required hospitalization. The events occurred after the second dose of mRNA-1273. The patient noted worsening of his breathing throughout the afternoon as well as the development of a productive cough. The patient self-administered an albuterol treatment and applied his nasal cannula. His symptoms did not improve so EMS was called. At the hospital, he was still seen to be hypoxic even with increased oxygen low rates and placed on noninvasive positive-pressure ventilation, started on steroids, scheduled breathing treatment and admitted for acute hypoxic respiratory failure.  The patient was treated for a presumed COPD exacerbation. The patient was discharged at his pre-hospital oxygen requirements.The rechallenge was not applicable as events occurred after second dose and no further dosing was reported or planned, based on information provided. The above mentioned medical history remains a confounder. The benefit-risk relationship of mRNA-1273 is not affected by this report.   Reporter did not allow further contact; Sender's Comments: This case concerns an elderly male patient with medical history of chronic obstructive/restrictive pulmonary disease, who experienced the unexpected events of COPD exacerbation and Acute hypoxic respiratory failure, which required hospitalization. The events occurred after the second dose of mRNA-1273. The patient noted worsening of his breathing throughout the afternoon as well as the development of a productive cough. The patient self-administered an albuterol treatment and applied his nasal cannula. His symptoms did not improve so EMS was called. At the hospital, he was still seen to be hypoxic even with increased oxygen low rates and placed on noninvasive positive-pressure ventilation, started on steroids, scheduled breathing treatment and admitted for acute hypoxic respiratory failure.  The patient was treated for a presumed COPD exacerbation. The patient was discharged at his pre-hospital oxygen requirements.The rechallenge was not applicable as events occurred after second dose and no further dosing was reported or planned, based on information provided. The above mentioned medical history remains a confounder. The benefit-risk relationship of mRNA-1273 is not affected by this report.