inclusion criteria: * participant or guardian health proxy must provide informed consent before any study assessment is performed. * male or female participants aged ≥ 12 years. * participants with coronavirus (sars-cov-2) infection confirmed ≤ 3 weeks prior to randomization by any test with local regulatory approval. * participants who are intubated and receiving mechanical ventilation due to covid-19-associated ards and have a pao2/fio2 of ≤ 300 mmhg within 6 -hours of randomization. participants with lung imaging showing bilateral or diffuse pulmonary infiltrates on chest x-ray or ct scan.

inclusion criteria: * participant or guardian health proxy must provide informed consent before any study assessment is performed. * male or female participants aged ≥ 12 years. * participants with coronavirus (sars-cov-2) infection confirmed ≤ 3 weeks prior to randomization by any test with local regulatory approval. * participants who are intubated and receiving mechanical ventilation due to covid-19-associated ards and have a pao2/fio2 of ≤ 300 mmhg within 6 -hours of randomization. participants with lung imaging showing bilateral or diffuse pulmonary infiltrates on chest x-ray or ct scan.

inclusion criteria: - participant or guardian health proxy must provide informed consent before any study assessment is performed. - male or female participants aged ≥ 12 years. - participants with coronavirus (sars-cov-2) infection confirmed ≤ 3 weeks prior to randomization by any test with local regulatory approval. - participants who are intubated and receiving mechanical ventilation due to covid-19-associated ards and have a pao2/fio2 of ≤ 300 mmhg within 6 -hours of randomization. participants with lung imaging showing bilateral or diffuse pulmonary infiltrates on chest x-ray or ct scan.

inclusion criteria: - participant or guardian health proxy must provide informed consent before any study assessment is performed. - male or female participants aged ≥ 12 years. - participants with coronavirus (sars-cov-2) infection confirmed ≤ 3 weeks prior to randomization by any test with local regulatory approval. - participants who are intubated and receiving mechanical ventilation due to covid-19-associated ards and have a pao2/fio2 of ≤ 300 mmhg within 6 -hours of randomization. participants with lung imaging showing bilateral or diffuse pulmonary infiltrates on chest x-ray or ct scan.