Houston Methodist first in the nation to try coronavirus...

Houston Methodist Hospital Saturday night transfused the blood plasma of a patient who has recovered from COVID-19 into a critically ill patient, the first hospital in the nation to try the experimental therapy.

A Houston individual who has been in good health for more than two weeks since being diagnosed donated the plasma for what’s known as convalescent serum therapy. The concept dates back to the Spanish flu pandemic of 1918.

“Convalescent serum therapy could be a vital treatment route because unfortunately there is relatively little to offer many patients except supportive care, and the ongoing clinical trials are going to take a while,” Dr. Eric Salazar, a physician scientist with Methodist’s Research Institute, said in a statement. “We don’t have that much time.”

On Sunday, Salazar said the team also transfused the same donor's plasma into a second critically ill patient.

Salazar said it is still "too early" to determine whether the therapy is benefiting the patients.

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The treatment was fast-tracked to the bedside over the weekend as the death toll in the pandemic caused by the coronavirus rose to more than 2,000 people in the United States, including 34 in Texas. The Food and Drug Administration earlier Saturday evening had approved Methodist's "emergency investigational new drug" application to test the therapy in the first patient.

Methodist Friday began recruiting donors from among the roughly 250 patients who have tested positive for the virus at the system’s hospitals. Donors gave a quart of plasma in a procedure, much like donating whole blood.

Dr. Marc Boom, Houston Methodist's president and chief executive officer, said the hospital felt obligated to try.

“There is so much to be learned about this disease while it’s occurring,” he said in a statement. “If an infusion of convalescent serum can help save the life of a critically ill patient, then applying the full resources of our blood bank, our expert faculty, and our academic medical center is incredibly worthwhile and important to do.”

Plasma from someone who has recovered from COVID-19 contains antibodies made by the immune system to attack the virus. The hope is that transfusing such plasma into a patient still fighting the virus may transfer the power of the antibodies into a healing, possibly life-saving therapy.

There is much literature on the theory behind the therapy, but results over the years have varied. A description of the treatment of five COVID-19 patients in China, published this week in the Journal of the American Medical Association, suggested that the treatment was beneficial.

In addition to its use in the 1918 flu pandemic, convalescent serum therapy was also tried during a diphtheria outbreak in the 1920s, a flesh-eating bacteria epidemic in the 1930s and the Ebola outbreak in Africa earlier this decade.

In New York City earlier this week, Gov. Andrew Cuomo had announced patient recruitment for plasma donations would begin in a matter of days. He said it would focus initially on the heavily hit New York City suburb of New Rochelle.

There are nearly 2,500 confirmed cases in Texas, including 744 in the Houston region. Four people have died here.