According to recent data, death rate is more than 20% for 75 years old hospitalized patients and older.

In case of aggravation, according to the latest observations, if they are refused for mechanical ventilation in intensive care, their death rate could reach 60% even for patients without comorbidity.

Apart from an increase in oxygen therapy, no specific treatment is currently proposed.

The control of the inflammatory component seems to be a key element to be able to influence the patients' health evolution.

Polyvalent intravenous immunoglobilins have immunomodulatory and anti-inflammatory properties with a favorable safety profile for these elderly patients and several clinical cases lead to positive impact in the caring for Covid patients.

This study objective is evaluation of the efficacy of polyvalent IVIg in combination with the standard management of patients aged 75 and over with SARSCov2 infection with acute respiratory failure (saturation ≤ 95%) requiring oxygen therapy> 5 L / min (i.e. patients considered as moderate to severe ARDS according to the Berlin definition, Pa02 / Fi02≤200) and disqualified from a care in the ICU.

Inclusion Criteria:

• Man or woman aged 75 and over
• SARS-coV2 infection confirmed by RT-PCR or thoraco-pulmonary CT
• Hospitalized in the acute general geriatrics unit of the Versailles Hospital Center
• Patient rejected from resuscitation
• Saturation ≤ 95% under oxygen therapy> 5 L / min (i.e. PaO2 / FiO2≤200mmHg according to the Berlin definition of ARDS) by means of a nasal cannula, a high concentration facial mask or another device similar oxygen distribution

Exclusion Criteria:

• Patient under palliative care

• Patient with contraindication to IV polyvalent Ig

  1. . Hypersensitivity to the active substance or to any of the excipients (L-proline)
  2. . Hypersensitivity to human immunoglobulins, especially when the patient has anti-IgA antibodies,
  3. . Patients with type I or II hyperprolinemia

• Patient under guardianship or curatorship

• Patient receiving another experimental treatment as part of an interventional study

• Moderate to severe dementia known: it must have been diagnosed before hospitalization and is defined by an MMSE <20/30 or a neuropsychological assessment with a diagnosis made.

• Patient not affiliated with a social security system in France

• ADL patients <4/6 and / or IADL <6/8