Can blood from coronavirus survivors help other people fight the disease?
Doctors in New York will soon test the idea on seriously ill hospital patients.
Blood from people who have recovered can be a rich source of antibodies, proteins that are made by the immune system to attack the virus. The part of the blood that contains antibodies, the so-called convalescent plasma, has been used for decades to treat infectious diseases such as Ebola and influenza.
“It’s scientifically difficult to know how valuable an illness is until you try,”
Dr. Reich said it was being tried as a treatment for hospital patients who had a moderately severe form of the disease and had difficulty breathing, but not for those who were in advanced stages of the disease.
“The idea is to find the right patients at the right time,” he said. “But it’s experimental.”
Researchers at Mount Sinai were among the first in the United States to develop a test that can detect antibodies in the recovery of patients. This is an integral part of this treatment strategy.
On Tuesday, the Food and Drug Administration gave permission to experimentally use the plasma to treat coronavirus patients in an emergency, and hospitals in New York quickly asked to participate, Dr. Bruce Sachais, chief medical officer of the New York Blood Center, which collects, tests and distributes the plasma.
“Our main focus is on how we can do this quickly so that hospitals can offer products to their patients,” said Dr. Sachais. “We have blood centers in New England, Delaware and the Midwest, so we can do the same in other regions. We work with other blood centers and hospitals that may collect their own blood and want to do so. We may not be able to collect enough plasma in New York to help the whole country. So we want to share it with other centers to help them. “
Dr. Reich said an email in which Mount Sinai employees who had recovered to consider donating plasma became “a little viral” and quickly got 2,000 responses.
However, volunteers must be carefully screened to meet strict criteria. Donors include people who tested positive for the virus in the event of illness, who recovered, who had no symptoms for 14 days, who were now tested negative – and who have high concentrations, also called titers, of antibodies that fight the virus. Dr. Reich said that the number of qualified people could initially be small due to delays and bottlenecks in the tests.
“Our expectation, based on reports from Chinese experience, is that most people who get better have high titer antibodies,” said Dr. Sachais. “Most patients who recover will have good antibodies in a month.”
Qualifying people are then sent to blood centers to donate plasma. The process, called apheresis, is similar to donating blood, except that the blood drawn from the patient is passed through a machine to extract the plasma and the red and white blood cells are then returned to the donor. Needles go into both arms: blood flows from one arm, flows through the machine and goes back to the other arm. The process typically takes 60 to 90 minutes and can deliver enough plasma to treat three patients, said Dr. Sachais.
People who have recovered have antibodies left over, and removing some will not endanger donors or reduce their own resistance to the virus, said Dr. Sachais. “We may get rid of 20 percent of their antibodies and they will be back a few days later.”
The plasma is tested to ensure that it does not carry infections such as hepatitis or H.I.V. or certain proteins that could trigger immune responses in the recipient. If it passes the tests, it can be frozen or used immediately. Each patient to be treated is given a unit, such as a cup, which is dripped into it like a blood transfusion. As with blood transfusions, plasma donors and recipients must have matching types, but the rules do not match those for transfusions.
“We believe this will be an effective treatment for at least some patients, but we don’t really know yet,” said Dr. Sachais. “Hopefully we will get some data from the first patients over the next few weeks to see if we’re on the right track.”
“With other coronavirus epidemics, I don’t think we have strong evidence,” he said. “We have no controlled data. There have been reports from SARS and MERS that patients have improved.”
He said the decision to try this approach was based in part on reports from China that it appeared to help patients. However, the reports are not based on controlled studies or final data.
Dr. Sachais said an article in a magazine that was not peer-reviewed described the treatment of 10 patients in China with one unit of convalescent plasma, saying that it was safe and appeared to reduce their virus levels quickly.
“It’s anecdotal,” he said.
A researcher who has not been associated with the new treatment plans said there is evidence to support the use of plasma from survivors.
“Four to six or eight weeks after infection, your blood should be full of antibodies that neutralize the virus and theoretically limit the infection,” said Vineet Menachery, virologist at the University of Texas Medical Department.
In studies on mice, he said, “If you can reduce virus replication ten to a hundred times, it can make the difference between life and death.”
He described the use of convalescent plasma as “a classic approach that is a really effective treatment method” – when there are enough donors with enough correct antibodies.
A potential risk is that the patient’s immune system can react to something in the plasma and cause additional diseases.
Although hospitals collect information about the patients being treated, the procedure is not conducted as part of a clinical trial. There will be no placebo group or other measures necessary to determine if treatment is working.
“People are so seriously ill now that it’s not the right time,” said Dr. Rich. “They’re in the hospital, they’re sick, in the intensive care unit, on ventilators. Some get sick so quickly, and it’s so serious for some people that we think it’s not the right moment.”
He said doctors would rely on science and evidence as much as possible.
But he added: “You see this steamroller coming towards you and you don’t want to passively sit there and let it roll over you. So you put together everything you need to fight it. This has the potential to help and that too Potential to harm, but we’ll only know later in the course of the disease and people have had the opportunity to try different things. “
Survivors seem ready to help.
“We get a lot of inquiries,” said Dr. Sachais. “A center sent a survey to better off patients and there were hundreds of responses saying they were interested in being donors. This will bring people together. People who have survived will want to do something for their New Yorkers. “