Last week, the U.S. Food and Drug Administration (FDA) approved the extraction of blood from patients recovering from COVID-19 as a treatment for new infections,media New Atlas reported. This therapy is known as recovery plasma therapy and dates back to the late 19th century. Some doctors now suggest that this may be our stopgap measure to contain the virus when developing more complex therapies and vaccines.
In the 1890s, Emil Behring, a German scientist, pioneered a new treatment for diphtheria. Belin, along with a Japanese doctor named Kitalychai Sanro, found that the serum of animals infected with certain toxins could be injected into humans to treat a variety of diseases.
Bellin then called these protective molecules “antitoxins” and optimized the therapy over the next decade. He eventually discovered that horses were the most effective animals to produce large amounts of serum antitoxins. In 1901, Bellin won the first Nobel Prize in Physiology and Medicine for developing these diphtheria serum therapies.
Today, we understand how this treatment works in theory, because we understand how the immune system of an organism produces antibodies to fight certain infectious agents. More than a century ago, however, scientists in immunology did not fully understand how serum therapy works. Bellin calls his blood a “very special juice” and uses terms such as disinfectant to describe how his serum therapy heals patients.
Throughout the first decades of the 20th century, this treatment was known as a recovery plasma therapy and was often used in outbreaks of infectious diseases. From measles and mumps to polio, blood products from recovering patients are common treatments. The therapy was widely deployed during the 1918 Spanish influenza pandemic. A meta-analysis of eight studies published between 1918 and 1925 showed that recovery plasma therapy significantly reduced mortality among people receiving the therapy.
Of course, the 2006 study has a great deal of limitation in interpreting these results, as the early 20th century case studies do not have the rigors of modern methods of research. These are not double-blind, randomized or placebo-controlled trials. The control group was derived from simply counting untreated patients in the same hospital or ward. Taking all these factors into account, the meta-analysis showed a total fatality rate of 16 per cent for patients with plasma therapy during recovery. The fatality rate was 37 per cent in the untreated control group.
By the middle of the 20th century, the treatment would eventually cease to exist. From the discovery of antibiotics to the development of complex vaccines, scientists have finally come up with more effective medical treatments.
But…… New treatments take time to develop, trial, and deploy. Also, when a new virus starts to spread through out of the population, people may not have enough time to wait. Especially when faced with a completely new virus, it has a high mortality rate and no treatment options. In Africa, recent similar case studies have inspired doctors in Hong Kong, China, to conduct impromptu restorative plasma studies that have demonstrated the potential efficacy of the Ebola virus. In the two months at the peak of the SARS outbreak in Hong Kong in 2003, 80 patients received recovery plasma therapy.
In the study, the overall mortality rate in the treatment group was 12.5%. During the same period, the average mortality rate in Hong Kong was 17%. More importantly, however, the study found that the timing of recovery plasma therapy significantly affected its success rate. Those who received treatment earlier (in this case, less than 14 days after the onset of symptoms) showed better outcomes than those who received treatment later.
A recent meta-study looked at the effects of restorative plasma therapy, which included clinical reports of diseases such as SARS, the Spanish flu route, and resulted in a 75 percent reduction in total mortality and treatment in patients. The 2015 study also confirmed that starting treatment early is critical to the effectiveness of treatment.
Or a stopgap measure for the treatment of COVID-19.
In the early days of the COVID-19 outbreak, Arturo Casadevall, an immunologist at Johns Hopkins University, revived the idea of a restorative plasma therapy after reports that it was being trialled in China. Casadevall not only proposes a century-old therapy as a potentially useful early treatment for patients who have recently been diagnosed with the virus, but he also suggests that it may be a useful preventive method for health care workers who are exposed to confirmed cases.
“It is expected that the serum of recovered patients will prevent SARS-CoV-2 infection in patients who are receiving it,” Casadevall and colleague Liise-anne Pirofski wrote in a recent opinion. If this holds, then people receiving recovery plasma therapy may be able to avoid a period of isolation. This allows them to continue to assume key functions of health-care providers. Serum in recovered patients can also be used to prevent illness in family members caring for COVID-19 patients at home. “
The FDA needs to consider a number of eligibility factors, including rules that require blood donors to be asymptomatic at least 14 days before they donate blood. Individual use of the treated plasma must still be approved by the FDA on a case-by-case basis.
Working with Casadevall and his Team at Johns Hopkins University, other scientists from across the United States are teaming up to quickly conduct trials to see the best way to use the treatment. Michael Joyner of the Mayo Clinic and Jeffrey Henderson of Washington University School of Medicine in St. Louis are providing institutional resources to drive these clinical trials.
“It’s a piece that can be done quickly, faster than drug development, because it basically involves donating and blood transfusions of plasma,” Henderson explained. “Once someone recovering from COVID-19 comes along, we have potential donors, and we can use the blood bank system to get the plasma and distribute it to patients who need it. “
There are still many questions to be answered before treatment is widely promoted. How many antibodies need to be detected in the blood of recovering patients in order to perform serum therapy effectively? How much restorative plasma is required to treat the disease? When is the best time to treat? Can treatment provide any reliable immunity for subjects who have not yet been infected with the virus?
Casadevall believes the answers to these questions can be found quickly, but he stresses that it will require resources to move quickly. “It’s all possible, but it takes effort, organization, resources… to do it,” Casadevall said. and people recovering from illness can donate blood. “
No one thinks this treatment is a panacea for COVID-19, but Casadevall and his colleagues reiterate that this may be a stopgap measure. More complex new therapies and vaccines may take at least 12 to 18 months to produce, so developing methods in the short term to improve patient prognosis and help prevent further proliferation can significantly reduce the burden on vulnerable medical networks and save lives.
Most importantly, the production and deployment of recovery plasma therapy requires only a pre-existing network of blood banks. The current U.S. blood collection and supply system can be quickly redeployed to begin collecting donations from recovered COVID-19 patients. Once Casadevall and his colleagues were able to test best practices for COVID-19 treatment, recovery plasma therapy could be extended to a large number of patients within months, flattening the spread curve and giving scientists more time to study effective vaccines.
“It is clear that the use of recovery-period serums will be a stopgap measure in the current epidemic,” Casadevall and Pirofski wrote in the Journal of Clinical Research. However, even local deployments require considerable coordination among different entities, such as infectious disease specialists, haematologists, blood bank specialists and hospital managers. Therefore, as we are in the midst of a global pandemic, we recommend that agencies consider the urgent use of recovery-period serums and begin preparations as soon as possible. Time is life. “