Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia; Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia; Acute psychosis; This literature-non-study case was reported in a literature article and describes the occurrence of ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia), COVID-19 PNEUMONIA (Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia) and ACUTE PSYCHOSIS (Acute psychosis) in a 55-year-old female patient who received mRNA-1273 (Spikevax) for COVID-19 prophylaxis.      Co-suspect product included non-company product DEXAMETHASONE for an unknown indication.    Concurrent medical conditions included Type 2 diabetes mellitus and Hypertension.   On an unknown date, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form and DEXAMETHASONE (Intravenous) at an unspecified dose. On an unknown date, the patient experienced ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia) (seriousness criteria hospitalization and medically significant), COVID-19 PNEUMONIA (Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia) (seriousness criteria hospitalization and medically significant) and ACUTE PSYCHOSIS (Acute psychosis) (seriousness criteria hospitalization and medically significant). The patient was hospitalized for 3 days due to ACUTE PSYCHOSIS. At the time of the report, ACUTE RESPIRATORY FAILURE (Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia), COVID-19 PNEUMONIA (Acute hypoxic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia) and ACUTE PSYCHOSIS (Acute psychosis) outcome was unknown.        The action taken with mRNA-1273 (Spikevax) (Unknown) was unknown.   For mRNA-1273 (Spikevax) (Unknown), the reporter did not provide any causality assessments.   Concomitant medications were not reported.  Patient had no past psychiatric history.  Patient did not exhibit any psychiatric symptoms during the initial admission.  Patient was re-admitted three days after the initial discharge, presenting with acute psychosis following the intravenous dexamethasone administration for seven days.  Authors concluded that clinicians should be aware of the acute neuropsychiatric side effects of corticosteroids and evaluate patients for delirium if clinically indicated.  Company comment: This literature-non-study case concerns a 55-year-old female patient, with no past psychiatric history, who experienced the unexpected serious (hospitalization and medically significant) events of acute hypoxic respiratory failure, COVID-19 pneumonia, and acute psychosis after the first dose of mRNA-1273 vaccine. She was admitted for acute hypoxic respiratory failure secondary to COVID-19 pneumonia with no psychiatric symptoms during the initial admission, however she was re-admitted three days after the initial discharge, presenting with acute psychosis following the intravenous dexamethasone administration for seven days. No exact vaccination dates and onset date of the events were provided; hence, latency could not be properly assessed. No further information is available at the time of this report. Treatment with dexamethasone could be a risk factor for acute psychosis. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This literature-non-study case concerns a 55-year-old female patient, with no past psychiatric history, who experienced the unexpected serious (hospitalization and medically significant) events of acute hypoxic respiratory failure, COVID-19 pneumonia, and acute psychosis after the first dose of mRNA-1273 vaccine. She was admitted for acute hypoxic respiratory failure secondary to COVID-19 pneumonia with no psychiatric symptoms during the initial admission, however she was re-admitted three days after the initial discharge, presenting with acute psychosis following the intravenous dexamethasone administration for seven days. No exact vaccination dates and onset date of the events were provided; hence, latency could not be properly assessed. No further information is available at the time of this report. Treatment with dexamethasone could be a risk factor for acute psychosis. The benefit-risk relationship of mRNA-1273 is not affected by this report.