Positives

• Convalescent plasma has been used successfully for immunocompromised Long COVID patients with prolonged SARS-CoV-2 infection due to inadequate antibody response, with case series documenting viral clearance and symptom resolution after transfusion PMC.
  
  

Negatives

• Convalescent plasma did not prevent disease progression in high-risk patients given it within the first week of symptoms, with the NIH outpatient trial stopped early in February 2021 for lack of efficacy NIH.
• Patients on convalescent plasma have reported transfusion-related complications in 5.7% of recipients, including cases of transfusion-associated circulatory overload and possible transfusion-related acute lung injury Nature Medicine.

Hurdles & Side Effects

• Convalescent plasma is administered by IV transfusion in a hospital or infusion-clinic setting and carries small but real risks of transfusion reactions, transfusion-related acute lung injury (TRALI), and viral transmission, requiring matched blood typing MedComm.
  
  
• As acute COVID-19 case loads dropped, convalescent plasma availability has narrowed; most US use is now restricted to immunocompromised patients with prolonged infection through individual hospital protocols The Lancet Infectious Diseases.