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Hopkins/Einstein Experts Recommend Using Antibodies from COVID-19 Survivors As Stopgap Measure to Treat Patients and Protect Healthcare Workers; Approach Has Seen Success in Deadly Pathogen Outbreaks for 100 Years

Countries fighting outbreaks of the novel coronavirus disease COVID-19 should consider using the antibodies of people who have recovered from infection to treat cases and provide short-term immunity—lasting weeks to months—to critical health care workers, argue two infectious disease experts--Arturo Casadevall, MD, PhD, Professor and Chair of the Department of the Molecular Microbiology and Immunology at The Johns Hopkins Bloomberg School of Public Health in Baltimore. and Liise-anne Pirofski, MD, Chief of the Division of Infectious Diseases at the Albert Einstein College of Medicine in New York City. In an open-access essay published online on March 13, 2020 in The Journal of Clinical Investigation ( Dr. Casadevall and Dr. Pirofski, wrote that the infusion of antibody-containing serum from convalescing patients has a long history of effective use as a stopgap measure against infectious diseases, and can be implemented relatively quickly—long before other antiviral treatments, monoclonal antibodies, and vaccines are developed, approved, and available. The JCI essay is titled “The Convalescent Sera Option for Containing COVID-19.” “In addition to public health containment and mitigation protocols, this may be our only near-term option for treating and preventing COVID-19, and it is something we can start putting into place in the next few weeks and months,” Dr. Casadevall says. To date, the novel coronavirus SARS-CoV-2 that appears to have originated in Wuhan, China, in late 2019 has caused outbreaks of COVID-19 across the world. As of March 12, there were 125,048 officially confirmed cases in 118 countries and 4,613 deaths from pneumonia caused by the virus, according to the World Health Organization’s Situation Report. Researchers now are expediting efforts to design and/or test potential treatments and vaccines. However, as this is a new coronavirus, none of these potential treatments is likely to be available within the next several months. And a vaccine is unlikely to be available in less than one year, perhaps longer. Physicians have long known that patients tend to make large numbers of antibodies against an infecting pathogen. These antibodies circulate in the blood of survivors for months and years afterward, and usually have the potential to bind to the pathogen and neutralize its ability to infect cells. The procedure for isolating serum, the fraction of blood containing antibodies, is also a long-established technology and can be performed using equipment normally found in hospitals and blood-banking facilities.

In this instance, individuals who recover from COVID-19 and are still in their convalescent phase would be asked to donate serum containing the antibodies that would then be processed for injection into sick patients and in those exposed to SARS-CoV-2.

Because of the ease of the technique, the many reports of its apparent effectiveness, and the basic plausibility of how it works, doctors once commonly used “convalescent sera” to treat patients or immunize persons at high risk when there was otherwise no defense against a pathogen—in outbreaks of measles, mumps, rubella, polio, and even the 1918 flu pandemic, as examples.

The practice, widespread before 1950, was curtailed after clinicians recognized that donor blood may contain other live pathogens and inadvertently spread disease. Today’s blood bank technology is much improved, with routine screening for pathogens such as hepatitis viruses and HIV, so the use of this method is now considered as safe as an ordinary blood transfusion, Dr. Casadevall says.

Moreover, serum from convalescing patients continues to be used in cases where doctors have no other good options. It was employed in the 2002–04 SARS epidemic, in several bird flu and swine flu epidemics, in an Ebola virus outbreak in Africa in 2013, in a recent outbreak of another coronavirus-caused disease called MERS, and even in the early stages of the COVID-19 outbreak in China.

In these cases, doctors have used the method on small groups of patients and without the usual clinical trial protocols. However, their reports suggest that the technique has an acceptable level of safety and is usually somewhat effective at reducing the viral burden and improving patient outcomes, especially when applied early in the disease course.

It is so far unclear how many patients who have recovered from COVID-19 would be needed to supply antibody-filled serum to treat a single infected patient or provide immunity to a single at-risk person. Dr. Casadevall says, however, that a little could go a long way if used for preventing infection or for treating infection in the early stages when the viral load is lower.

“How many patients you can help, per volume of convalescent serum, will depend on how you use it,” he says. “And we’ll have to put protocols in place to make sure that the use of this sera is safe. But we’re not talking about research and development—this is something that physicians, blood banks, and hospitals already know how to do and can do today.”

Dr. Casadevall and other physicians are now trying to establish the practice of using convalescent sera as a preventive and treatment for COVID-19, in specific U.S. hospital networks and ultimately nationwide.

In a February 27, 2020 Wall Street Journal op-ed (, Dr. Casadevall pointed to a notable case preventing a measles outbreak at a U.S. prep school in 1934.

Experts around the U.S. are rushing to implement the treatment in several different areas, including New York City, Dr. Casadevall says. Doctors in Shanghai have already used the plasma therapy with newly infected coronavirus patients in China and have reported promising early results. Japan's largest drugmaker, Takeda Pharmaceuticals, has also begun testing the therapy (

The Johns Hopkins Research Team ( has put initial funding toward Dr. Casadevall's project, to purchase equipment and set up an operation in Baltimore. Dr. Casadevall and his team are working now with state and federal officials to try to secure more resources.
Experts say a challenge of the technique is that precise timing is important in order to maximize the boost to a patient's immunity. The treatment is not envisioned as a panacea to treating coronavirus, but a temporary measure that could help until stronger options such as vaccines are available.

"It's all doable—but to get it done it requires effort organization, resources… and people who have recovered from the disease who can donate the blood," Dr. Casadevall says. He adds that many people have stepped up to the plate at Hopkins and are already working to put this system in place.
Dr. Casadevall says he believes the solution "could do a lot locally" in the Baltimore region. He also noted that Johns Hopkins could become the Investigational New Drug (IND) center in the U.S. for this treatment, helping to administer it across states.

[Johns Hopkins press release] [Johns Hopkins HUB article by Katie Pierce] [Johns Hopkins Coronavirus Resource Center] [JCI essay]

[Science Alert] [NBC News]