Investigational Role of Convalescent Plasma in the Management of COVID-19 Disease in Inpatient & Outpatient Settings

Introduction:Historically, both convalescent plasma & hyperimmune globulin have been tried & tested in multiple viral outbreaks in order to confer passive immunity. These products are obtained from previously infected subjects who have fully recovered and are opined to have generated optimal immune response (polyclonal antibodies to the causative pathogen at sufficient titre and biologic activity) to confer passive immunity in the recipient. Neutralizing antibodies are the main active component of such products. In this article practical aspects of obtaining and administering convalescent plasma and evidence-base for its use in the management of COVID-19 disease in inpatient & outpatient settings is presented.
Method:A comprehensive search of PubMed & EMBASE from March 2020 to July 2022 was made using 3 search items: COVID-19, convalescent plasma, and hyperimmune globulin. The search items were combined using the Boolean operator. Societal guidelines reviewed at the time of writing this article include: US Food and Drug Administration (FDA), Association for the Advancement of Blood & Biotherapies (AABB), American Society of Hematology (ASH), International Society on Thrombosis and Haemostasis (ISTH), and National Institute for Health and Care Excellence (NICE) in the United Kingdom.
Results: Administering COVID-19 convalescent plasma can confer immediate passive immunity that may help shorten the duration of the COVID-19 disease &/or diminish its severity thus preventing life-threatening complications. Besides FDA issued EUA of considering convalescent plasma therapy in immunocompromised individuals with severe COVID disease, other investigational indications for convalescent plasma therapy include a) individuals exposed to SARS-CoV-2 who have not yet become ill (i.e. post-exposure prophylaxis), and b) individuals who are at high-risk of exposure or high-risk of severe disease if exposed (i.e. pre-exposure prophylaxis). Convalescent plasma has recently been successfully tried in the outpatient setting to help reduce disease severity and the incidence of hospitalizations.
Conclusion: Convalescent plasma therapy remains an investigational approach to treating severe COVID disease both in inpatient and outpatient settings. Whereas more data is needed to establish its indications, safety, and relative efficacy in novel COVID-19 variant infection cases, its use in immunocompromised individuals with severe COVID disease remains a valid therapeutic consideration.

Keywords:COVID-19; Convalescent plasma; Hyperimmune globulin