Inclusion Criteria:

- Age ≥ 18 years.

- Severe acute respiratory infection (SARI), defined as a suspected infection of the
respiratory tract that meets each of the following 4 criteria:

1. Onset in the last 10 days AND

2. Results in hospitalization AND

3. At least one symptom or sign of respiratory illness (defined as purulent
sputum, new or worsened cough, new or worsened dyspnea, tachypnea with
respiratory rate ≥22 breaths per minute, rales, or bronchial breath sounds) AND

4. At least one symptom or sign of acute infection (defined as a temperature ≥38°C
or ≤36°C, feverishness, chills, altered mental status, a white blood cell count
of >12,000/mm3, <4,000/mm3, or >10% immature neutrophils, or imaging findings
consistent with acute respiratory infection).

- Hypoxemia, defined as meeting one or more of the following at the time of
eligibility assessment:

1. An oxygen saturation <92% in a patient who does not receive chronic
supplemental oxygen OR

2. Receipt of ≥3 liters per minute of supplemental oxygen or a fraction of
inspired oxygen of ≥0.35 in a patient who does not receive chronic supplemental
oxygen OR

3. Receipt of a flow rate of supplemental oxygen ≥3 liters per minute greater than
pre-illness baseline or a fraction of inspired oxygen ≥0.10 greater than
pre-illness baseline in a patient who receives chronic supplemental oxygen.

Exclusion Criteria:

- Hospitalized for >72 hours

- Primary etiology of hypoxemia is a condition other than respiratory infection

- Known allergy or adverse reaction to systemic corticosteroids

- Known active infection with SARS-CoV-2, known active infection with Pneumocystis
jirovecii, or another established indication for systemic corticosteroids

- Known active disseminated or pulmonary infection with Mycobacterium tuberculosis,
Aspergillus, Blastomyces, Coccidioides, Cryptococcus, Histoplasma, or Strongyloides
species; active systemic infection with herpes simplex virus, varicella zoster
virus, or cytomegalovirus; or another established contraindication to systemic
corticosteroids

- Prisoner

- Treatment is prioritizing end-of-life symptom management over prolongation of life

- Investigator determines that participation in the trial is not in the patient's best
interest

- Receipt of greater than 14 days of systemic corticosteroids at a dose equivalent to
greater than 10 mg of prednisolone per day in the 30 days prior to hospital
presentation (i.e., chronic corticosteroids)

- Receipt of systemic corticosteroids at a dose equivalent to greater than 30 mg of
prednisolone per day on 2 or more calendar days since hospital presentation

- Clinicians determine that the administration of systemic corticosteroids at a dose
equivalent to greater than 10 mg of prednisolone per day is required, or is likely
to be required in the next 24 hours, for the optimal care of the patient (such as
for acute exacerbation of chronic obstructive pulmonary disease, adrenal
insufficiency, asthma, continuation of chronic corticosteroid therapy, or severe
shock)

- Clinicians determine that the administration of systemic corticosteroids is not
consistent with the optimal care of the patient (such as for recent peptic ulcer
disease, recent gastrointestinal bleeding, severe burns, severe delirium, severe
hyperglycemia or diabetic ketoacidosis, or severe hypertension)

- Patient (or surrogate decision-maker / legally authorized representative) declines
to provide informed consent to participate