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National clinical study on convalescent plasma

Héma-Québec was involved in a national clinical trial project, CONCOR-1, with the objective of developing a passive immunization program for treating people with COVID-19.


The CONCOR-1 study was initiated to determine whether a transfusion of plasma from donors who had recovered from COVID-19 (convalescent), and that contains antibodies against the virus, could be an effective strategy in treating infected people.

The teams sought to determine whether the antibodies transmitted to patients can help neutralize and eliminate the virus, thereby reducing the severity of the disease and speeding up patients’ recovery.

Héma-Québec’s role in this project involved recruiting individuals who had contracted and recovered from COVID-19 and agreed to donate plasma; our organization was also mandated to carry out analyses, in its labs, to demonstrate the presence of antibodies against the virus in convalescent plasmas. A total of 1,175 units of plasma were collected from 279 donors as part of this clinical trial.

After an interim analysis performed by an independent committee, it was found that the results observed to date leave little hope that this treatment will prove effective, at least in the type of patients included in the study. Therefore, the people in charge of the CONCOR-1 study, led by doctors Donald Arnold, Jeannie Callum and Philippe Bégin, announced that they were discontinuing patient recruitment as of February 2, 2021. The experts will conduct a detailed analysis of the results to determine if future studies should be considered for evaluating the effectiveness of convalescent plasma in other groups of patients with COVID-19.

Héma-Québec would like to thank all the donors who took part in this project. Their involvement has helped advance the research into the best protocols for treating patients with COVID-19.