A major Houston hospital is spearheading a crucial treatment in the ongoing battle against COVID-19. Houston Methodist is the first academic medical center in the nation to be approved by the FDA to transfuse donated plasma from a recovered COVID-19 patient into a critically ill patient.

The experimental treatment was fast-tracked as the death toll in the coronavirus pandemic soared to more than 2,000 people across the United States and more than 100,000 Americans sick from the virus, according to a statement.

The concept of the treatment centers around the idea that plasma from someone who has recovered from COVID-19 contains antibodies made by the immune system and used to kill the virus. Transfusing antibody-rich plasma into a COVID-19 patient who is still fighting the virus may transfer the power of the antibodies into a healing, possibly life-saving therapy, per the hospital.

Donating plasma is similar to donating blood and takes about an hour, according to Methodist. Plasma donors are hooked up to a small device that removes plasma while simultaneously returning red blood cells to their bodies. Unlike regular blood donation in which donors have to wait for red blood cells to replenish between donations, plasma can be donated more frequently, as often as twice a week.

Known as convalescent serum therapy, the concept dates back more than a century, when similar treatments were used during the Spanish flu pandemic of 1918, a diphtheria outbreak in the 1920s, a flesh-eating bacteria epidemic in the 1930s, and during other outbreaks of infectious diseases.

Most recently, a description of the treatment of five patients in China was published this week in the Journal of the American Medical Association, suggesting that the treatment was beneficial.

According to Methodist, scientists there recruited blood plasma donors from among approximately 250 patients who have tested positive for the COVID-19 virus at Houston Methodist hospitals. Willing donors were immediately identified; each gave a quart of blood plasma in a procedure much like donating whole blood.

The first recovered COVID-19 patient to donate plasma was an individual from the Houston metropolitan area who has been in good health for more than two weeks, according to the hospital. The plasma was then transfused into a COVID-19 patient at Houston Methodist.

Houston Methodist’s convalescent serum therapy treatment is classified as an “emergency investigational new drug protocol” that requires FDA approval for each patient infused with donated convalescent serum, according to the hospital. Houston Methodist physician scientists will continue to seek additional FDA approval for follow-up studies, as time is of the essence.

“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,” said Dr. Eric Salazar, principal investigator and a physician scientist in the Department of Pathology and Genomic Medicine at the Houston Methodist Hospital and Research Institute, in a statement. “We don’t have that much time.”