By Allison Proffitt

April 16, 2020 | In our pell-mell race to learn more about the SARS-CoV-2 virus and how best to treat the disease it causes, blood plasma of recovered patients is garnering a lot of attention. Researchers all over the world are exploring how blood plasma from patients who have tested positive for SARS-CoV-2 might help others who are sick.

“Immune (or ‘convalescent’) plasma refers to plasma that is collected from individuals, following resolution of infection and development of antibodies. Passive antibody therapy [or passive immunization], through transfusion of convalescent plasma, may prevent clinical infection or blunt clinical severity in individuals with recent pathogen exposure,” write the Johns Hopkins University authors of a nuts-and-bolts guidebook on the deployment of convalescent plasma for the prevention and treatment of COVID-19 published last week in the Journal of Clinical Investigation (DOI: 10.1172/JCI138745).

It’s an idea with strong historical support. Passive immunization has been used for a century, since successfully treating diphtheria and tetanus in 1890 and was used in both of the most recent coronavirus epidemics: SARS1 in 2003 and MERS in 2012.

The team from Johns Hopkins that authored the guidebook wanted to help providers rapidly scale up their ability to deliver convalescent plasma therapy against COVID-19. Among the outlined protocols are criteria for eligible donors of blood plasma, how hospitals can mobilize donors and work with local and national blood centers, methods for prescreening donors, and the risks and potential benefits of the therapy.

On Monday, FDA released its guidance for industry on investigational COVID-19 convalescent plasma. “Although promising, convalescent plasma has not yet been shown to be safe and effective as a treatment for COVID-19,” the guidance states. “Therefore, it is important to study the safety and efficacy of COVID19 convalescent plasma in clinical trials.”

Convalescent plasma hasn’t been approved for use by FDA for treating COVID-19 patients, the guidance emphasizes, and so administering or studying the use of COVID-19 convalescent plasma must come through clinical trials or IND application for expanded access for patients with serious or immediately life-threatening COVID-19 disease.

Donors can be identified by either a diagnostic test at the time of illness or a positive serological test for SARS-CoV-2 antibodies after recovery, if prior diagnostic testing was not performed, according to the guidance.

Some Trials Underway

“Despite a favorable historical record, few controlled trials have been performed to evaluate the efficacy of convalescent plasma, in large part due to its emergency application in times of epidemics,” the Hopkins authors observe. But now, new clinical trials around the world are putting the theory to the test.

Johns Hopkins has launched clinical trials to test the therapeutic approach in people who are at high risk for severe COVID-19 illness and have been exposed to people who have tested positive for the virus.

In Canada, scientists from Héma-Québec have been gathering convalescent plasma to develop a passive immunization program and have launched a nationwide clinical trial. If results are conclusive, a clinical offer would be immediately put in place for the hospitalized population. The effort has broad support, pooling the strengths of research centers and institutions across the country including 50 centers across Canada. The pediatric component is also being co-developed with researchers at Toronto's Hospital for Sick Children (SickKids).

"Everyone wants to be where they can be most useful in the current crisis. While the infectious disease and critical care teams are on the front lines, our teams are making a difference by using their research expertise to advance the search for solutions. No one wants to sit on the sidelines!" said Dr. Gerald Batist, Director of the Segal Cancer Centre at the Jewish General Hospital, in a press release announcing the work.

The University of Chicago Medicine is also launching a clinical trial, recruiting plasma donors from Chicago and treating patients hospitalized at UChicago Medicine. For the Chicago trial, only the safety and feasibility of procedures for identifying donors, collecting plasma donations and administering transfusions is being investigated; effectiveness of such a treatment will require additional trials.

Blood In Biobanks

Industry is joining the effort as well. Biological Specialty Company (BSC)—a company supplying pharma, biotech, diagnostic and government researchers with human blood products for scientific research—has launched an at-home blood donation service for COVID-19 positive patients.

“It is critically important that the scientific community has access to COVID-19 positive blood samples to advance medical discoveries. We have received hundreds of calls from researchers looking for these samples and most COVID-19 survivors want to do everything they can to help eradicate this disease,” said Lori Ball, chief operating officer at BSC in a statement yesterday announcing the effort.

BSC is deploying mobile donation units to the homes of patients who are sick and quarantined with COVID-19. Patients contact BSC personally and answer demographic questions including age, race, gender, medications taken, co-morbidities, and smoking status and questions about their illness such as symptoms and date of onset.

In alignment with the FDA guidance, BSC is only seeking blood donors with COVID-19 positive test results confirmed by a diagnostic nasal swab or serology test. “We have a HIPAA compliant email system which we will direct donors to submit a copy of their diagnostic results,” Courtney Noah, SVP, Marketing & Client Services, told Clinical Research News by email. “This process is confidential and will be coordinated after the patient contacts BSC.”

A BSC phlebotomist, dressed in full personal protective equipment (PPE), will arrive at the patient’s home, explain the informed consent and collection process, and collect the blood sample. Samples will be sent to BSC’s lab for processing and distribution.

BSC is, “working closely with researchers and diagnostic companies to perform confirmation serology testing on the material that is collected,” Noah continued. Serology results won’t be returned to blood donors but does provide researchers confidence that the material meets their specifications.