Researchers ask if survivor plasma could prevent coronavirus

Survivors of COVID-19 are donating their blood plasma in hopes it helps other patients recover from the coronavirus. And scientists are testing if the donations might prevent infection in the first place.

Thousands of coronavirus patients in hospitals around the world have been treated with socalled convalescent plasma — including more than 20,000 in the U.S. — with little solid evidence so far that it makes a difference. One recent study from China was unclear, and another from New York offered a hint of benefit.

With more rigorous testing of plasma treatment underway, Dr. Shmuel Shoham of Johns Hopkins University is launching a study asking the next logical question: Could giving people survivors’ plasma right after a high-risk exposure to the virus stave off illness? To tell, researchers at Hopkins and 15 other sites will recruit health workers, spouses of the sick and residents of nursing homes where someone just fell ill.

It’s a strict study: The 150 volunteers will be assigned randomly to get plasma from COVID-19 survivors that contains coronavirus-fighting antibodies or regular plasma. Scientists will track if there’s a difference in who gets sick.

If it works, survivor plasma could have important ramifications until a vaccine arrives — raising the prospect of possibly protecting high-risk people with temporary immune-boosting infusions every so often.

When the body encounters a new germ, it makes proteins called antibodies that are specially targeted to fight the infection. The antibodies float in plasma — the yellowish, liquid part of blood. Because it takes a few weeks for antibodies to form, the hope is that transfusing someone else’s antibodies could help patients fight the virus before their own immune system kicks in.