Humanity faces challenges from two viral outbreaks: hantavirus on a cruise ship and a resurgence of Ebola in Africa. Currently, there are no vaccines or antiviral drugs for these viruses, leaving supportive therapy as the only option. Medical experts often focus on quarantine, isolation, and developing new treatments but overlook convalescent plasma, a therapy available from survivors.

Convalescent plasma involves the transfer of antibodies produced by individuals who recover from viral diseases to others who are affected. This method has historical precedence. It was used during the 1918 influenza pandemic and treated over 600,000 Americans during the first year of the COVID-19 pandemic, significantly reducing mortality rates. In 2023, convalescent plasma showed promising results during a West Nile virus outbreak in Israel.

While convalescent plasma has been used in past outbreaks of hantavirus and Ebola, its efficacy was limited by late administration and insufficient antibody levels. Establishing convalescent plasma’s effectiveness has been historically challenging due to the emergency conditions during outbreaks and their short durations. The prolonged nature of the COVID-19 pandemic allowed multiple clinical trials to validate its use. However, early studies conducted on late-stage patients damaged its reputation.

Later trials confirmed its efficacy when administered early with adequate antibody levels, validating convalescent plasma as a therapy from the COVID-19 experience. In 2024, the FDA approved COVID-19 convalescent plasma for immunosuppressed patients, making it the sole antibody therapy for COVID today. Despite this validation, convalescent plasma remains underutilized due to misconceptions and logistical challenges.

Experts often claim difficulties in under-resourced regions due to requirements for transfusion services, yet over 50 countries, including many with limited resources, employed it against COVID. Concerns about standardization are addressed by measuring antibody content. Some hesitation may stem from its age, although its longevity doesn’t negate efficacy, akin to aspirin used since ancient times.

Viewpoints on convalescent plasma reflect unfamiliarity, as it is predominantly employed during emergencies and subsequently forgotten. Punic uptake is also hindered by the absence of industry promotion. Unlike profitable treatments, convalescent plasma relies on donors, public health authorities, transfusion services, and physician willingness.

“Convalescent plasma is a public good with no profit,” explains Arturo Casadevall, M.D., Ph.D., a prominent proponent of this method.

Governmental health agencies have a vital role in its success by coordinating logistics to collect, test, and distribute plasma. During COVID-19, FDA involvement was crucial for its deployment, illustrated by life-saving interventions.

Safety and efficacy data acquired from registries, as done by the FDA in 2020, support convalescent plasma even absent randomized clinical trials for new infections. Historically, convalescent plasma was misapplied to critically ill patients, similar to early COVID-19 deployment. Optimal results arise from early use, as shown by halving hospitalizations in COVID outpatient cases.

Public health bodies can identify survivors willing to donate plasma and evaluate their antibodies for hantavirus and Ebola. Each donor can aid in treating three patients, with donated units frozen for future use. Convalescent plasma offers interim relief until the development of vaccines, antiviral drugs, and monoclonal antibodies.

Arturo Casadevall, M.D., Ph.D., Bloomberg Distinguished Professor and Chair of Molecular Microbiology and Immunology at Johns Hopkins School of Public Health, emphasized these points based on extensive research and over 100 published works on convalescent plasma.