Hypothesize: early administration of convalescent plasma containing polyclonal neutralizing Abs may inhibit viral entry and replication (as recently suggested in vitro) and consequently blunt an early pro-inflammatory pathogenic endogenous Ab response.
Potential donors of convalescent plasma will be identified through various means, including hospitals taking care of such patient, practitioners treating outpatients or specific social messaging. Convalescent patients at least 14 to 28 days (per at date regulation regarding blood donation) after the symptoms resolution will be invited to undergo plasma apheresis, pending general eligibility such as an age between 18 and 65 years old and weight not less than 50 kg.
Two convalescent plasma units of 200 to 220 ml each will be transfused i.v. as early as possible and no later than 10 days after onset of clinical symptoms. In the absence of acute unforeseen adverse events in the first 3 patients, an additional 2 plasma units of 200/220 ml each will be transfused 24 hours after first 2 units: a total of 4 units / patient. Transfusion monitoring, treatment and reporting of adverse events will be performed per ANSM hemovigilance regulation regarding transfusion of labile blood products as well as through the specific clinical trial vigilance.
An average of 120 participants will be expected (60 participants in each arm). Availability of ABO compatible plasma will be checked by investigator when a Corimmuno patients is eligible. If so, randomization will be undertaken and patient will be offered to participate in this nested trial if he is allocated to the experimental arm.
An interim analysis is performed at mid-trial, but inclusions are not frozen to wait for the interim analysis.
