* pregnant women * women at reproductive age not willing to avoid unprotected sexual intercourse up to day 30 after study initiation. * women in the breastfeeding period * patients receiving experimental treatments under development within 30 days prior to study initiation. * patients with a previous history of allergic reactions to blood or blood-components transfusion. * diagnosis or clinical suspicion of an alternative microbiological cause for pneumonia besides covid-19 * use of systemic corticosteroids within 15 days prior to entering the study.

* pregnant women * women at reproductive age not willing to avoid unprotected sexual intercourse up to day 30 after study initiation. * women in the breastfeeding period * patients receiving experimental treatments under development within 30 days prior to study initiation. * patients with a previous history of allergic reactions to blood or blood-components transfusion. * diagnosis or clinical suspicion of an alternative microbiological cause for pneumonia besides covid-19 * use of systemic corticosteroids within 15 days prior to entering the study.

- pregnant women - women at reproductive age not willing to avoid unprotected sexual intercourse up to day 30 after study initiation. - women in the breastfeeding period - patients receiving experimental treatments under development within 30 days prior to study initiation. - patients with a previous history of allergic reactions to blood or blood-components transfusion. - diagnosis or clinical suspicion of an alternative microbiological cause for pneumonia besides covid-19 - use of systemic corticosteroids within 15 days prior to entering the study.

- pregnant women - women at reproductive age not willing to avoid unprotected sexual intercourse up to day 30 after study initiation. - women in the breastfeeding period - patients receiving experimental treatments under development within 30 days prior to study initiation. - patients with a previous history of allergic reactions to blood or blood-components transfusion. - diagnosis or clinical suspicion of an alternative microbiological cause for pneumonia besides covid-19 - use of systemic corticosteroids within 15 days prior to entering the study.