By Eamon Dreisbach
Two randomized, placebo-controlled clinical trials at Johns Hopkins Medicine aim to determine whether blood plasma will be effective as prophylaxis against COVID-19, a strategy that would be “enormously valuable” and has been efficacious against other viral diseases.
The first trial, which is looking at prophylaxis, is enrolling health care workers and individuals at high risk with significant exposure to the virus. Individuals will be randomly assigned to receive either convalescent or nonconvalescent plasma to test for a preventive effect.
The second trial is enrolling individuals with mild cases of COVID-19 who are isolated at home. Participants will be randomly assigned to receive either convalescent or nonconvalescent plasma to test whether individuals receiving convalescent plasma are less likely to develop more serious symptoms. “There is a commitment by many physicians and scientists to make sure that this is tested and tested adequately so that we can give society something that is enormously valuable — the knowledge of when, how and if to use plasma,” Arturo Casadevall, MD, PhD, chair of molecular microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health, said at media briefing on Thursday. “In every epidemic since 1900, from the 1918 influenza pandemic, to the SARS epidemic, to the Ebola epidemic, physicians often reach out to use plasma because it is something that is available once you have survivors. But it is very difficult, in the middle of an epidemic, to organize the kind of rigorous clinical trials that are needed to obtain that kind of information.”
Casadevall noted that obstacles to beginning the trials included a lack of existing infrastructure for this type of research, as well as issues locating patients who could be accurately confirmed to have recovered from COVID-19.
“There are obstacles, but we’re getting better every day,” he said. “We’re learning how to do this and do it better.” As of Thursday, 7,200 patients have been treated for COVID-19 using plasma, according to Casadevall, and the trials are expected to begin next week.
“What we have today is a very large amount of historical information demonstrating that plasma works against viral diseases,” Casadevall said. “We have large amounts of basic science telling us how antibodies work that support the use of plasma and we have anecdotal data that have been published. We don’t yet have the data that we want in regard to COVID-19, but there are a lot of suggestive and highly hopeful data that this therapy may be helpful.”
The FDA and the Red Cross, in collaboration with the FDA, are also currently accepting blood plasma donations from recovered COVID-19 patients. Patients who have fully recovered from the virus for a minimum of 2 weeks and have a prior diagnosis documented via a lab test are encouraged to donate. The FDA emphasizes that further investigation is still needed to determine the efficacy of convalescent plasma as a treatment for COVID-19.
American Red Cross. Plasma donations from recovered COVID-19 patients. Accessed May 7, 2020.
FDA. Donate COVID-19 plasma. Accessed May 7, 2020.
Disclosure: Casadevall reports the studies are being funded by Bloomberg Philanthropies, Johns Hopkins University and the state of Maryland.