- covid-19-negative subject - subject's age < 18 years - more than 7 days since initiation of mechanical ventilation - patient, surrogate or physician not committed to full intensive care support. - positive pregnancy test at the time of screening. - patients dependent on the sponsor, investigator and their employees, as well as persons dependent on the manufacturer of the investigational drug

- covid-19-negative subject - subject's age < 18 years - more than 7 days since initiation of mechanical ventilation - patient, surrogate or physician not committed to full intensive care support. - positive pregnancy test at the time of screening. - patients dependent on the sponsor, investigator and their employees, as well as persons dependent on the manufacturer of the investigational drug