Israel’s Magen David Adom medical rescue service is preparing to collect blood plasma donations from coronavirus patients who have recovered, in an effort to produce an antibody treatment for COVID-19 patients who are in serious condition.
Plasma treatments are commonly used to treat viruses, but they have yet to be proven effective against the coronavirus causing the pandemic. The evidence on the subject in the medical literature is limited and preliminary at this point.
A Chinese military doctor, Shangen Zheng, reported that his team has so far treated 10 patients in Hubei province with plasma, and data from additional patients are being assessed. Last week in the United States, the Food and Drug Administration approved the experimental use of plasma from recovered coronavirus patients as an emergency treatment for people in critical condition. It is already being used in New York, the largest coronavirus hotspot in the country.
In Israel, 132 people are deemed to have fully recovered from the disease. This relatively small number stems from the fact that recovery from COVID-19 takes between four and six weeks. As the number of those who have recovered increases, there will be a basis for expanding the use of the antibody treatment.
Such a use of antibodies is a passive treatment, in which patients gets an infusion of antibodies into their bloodstreams that is designed to help them cope with illnesses caused by viruses or bacteria. This is in contrast to a vaccine, which is designed to prompt patients’ own immune systems to produce their own antibodies, a process that occurs over several weeks.
Plasma with antibodies was used to treat SARS patients during that virus outbreak in 2002, and 10 years later to treat MERS.
“We are in the organizing stages and hope to begin shortly,” said Prof. Eilat Shinar, the blood services deputy director Magen David Adom. “Those who have recovered from corona will be invited to donate plasma thorough a special method [called pheresis], in which we collect only the plasma from the donor and return all the other blood components to him. The goal is to take three units – some 500 to 600 milliliters – of plasma from every person who has recovered.”
“Some of the plasma units will be used for intravenous treatment,” Shinar added, “while the rest will be immediately frozen, in an effort to collect enough plasma to prepare immunoglobulin [antibody] concentrate with which other patients will subsequently be treated.”
Collecting the plasma donations is only part of the process. “The use of plasma and antibodies requires two basic tests to determine its possible efficacy,” Shinar explained.
“The first is to test for the quantity of antibodies. A low quantity won’t do the job. The second is to test for the effectiveness of the antibodies, a test that examines how the donor’s antibodies deal with the virus. Not all antibodies are equally effective,” she said. “In general, it’s a treatment that has medical logic. We hope it will also prove itself.”