To the Editor—Antimicrobial preauthorization is a core strategy utilized by antimicrobial stewardship programs (ASPs). ^{Reference Dellit, Owens and McGowan1} ASPs have played an important role in coronavirus disease 2019 (COVID-19) response efforts, including in the preauthorization of novel therapeutic agents such as remdesivir. ^{Reference Stevens, Patel and Nori2,Reference Mazdeyasna, Nori and Patel3} On August 23, 2020, the US Food & Drug Administration (FDA) released an emergency use authorization (EUA) for the use of convalescent plasma in treating hospitalized patients with COVID-19. ⁴ An important question is what role, if any, ASPs should play in the convalescent plasma distribution process. To our knowledge, ASPs have never been involved in the preauthorization of blood products like convalescent plasma. There are numerous potential advantages and disadvantages to consider regarding ASP involvement in the convalescent plasma preauthorization process (Table 1). The effectiveness of convalescent plasma in the treatment of COVID-19 is still unclear. The data regarding convalescent plasma use are limited. As of June 22, 2020, the Infectious Diseases Society of America (IDSA) COVID-19 treatment guidelines recommend the use of convalescent plasma only in the context of a clinical trial. ^{Reference Bhimraj, Morgan and Shumaker5} Importantly, enrollment in existing trials has been potentially compromised by the EUA announcement. Major scientific organizations will likely continue to support guidelines emphasizing convalescent plasma use only in the context of clinical trials. It is also possible that additional study data will become available that will influence convalescent plasma use. This uncertainty about the optimal role of convalescent plasma supports the use of preauthorization to allow for real-time adjustment of convalescent plasma use in a controlled, optimized fashion.

Table 1. Considerations For and Against Antimicrobial Stewardship Program (ASP) Involvement in COVID-19 Convalescent Plasma Preauthorization

Many ASPs have been responsible for the creation and maintenance of COVID-19 treatment guidelines and are ideally situated to inform frontline clinicians about the optimal use of convalescent plasma relative to other therapies. Preauthorization, coupled with local treatment guidelines, would enhance the optimal use of convalescent plasma. Additionally, the new convalescent plasma EUA may increase demand for convalescent plasma use, resulting in timely access issues. A preauthorization process utilizing the best available evidence would facilitate providing convalescent plasma to patients who may benefit.

Health systems would benefit tremendously from ASP involvement in the COVID-19 convalescent plasma distribution process. ASPs can provide guidance for incorporation of convalescent plasma into local treatment guidelines, can provide insight and guidance based on their experiences with other COVID-19 focused EUAs (including hydroxychloroquine, now revoked ⁶ , and remdesivir ⁷ ), and can help develop processes for convalescent plasma eligibility screening and preauthorization. If health systems do not adopt preauthorization for convalescent plasma, we recommend that use be carefully monitored to ensure that this resource is being used optimally. ASPs have proven integral in COVID-19 response efforts—investing in and scaling up ASP resources will assist health systems adapt and respond to evolving pandemic challenges.