Get all the latest news on coronavirus and more delivered daily to your inbox. Sign up here.

A Houston-area hospital became the first hospital in the U.S. to transfuse blood plasma of a recovered COVID-19 patient into one that is critically ill, an experimental therapy that could be used in the fight against the novel coronavirus.

The Houston Chronicle reported that Houston Methodist Hospital transfused the plasma on Saturday night, noting the individual who donated the plasma had been in good health for more than two weeks. The procedure, known as convalescent serum therapy, dates back more than 100 years and was first used in the Spanish flu pandemic of 1918 and subsequent other outbreaks of infectious diseases during the 20th century.

"Here at Houston Methodist, we have the capability, the expertise and the patient base from our health care system, and we feel obligated to try this therapy," said Houston Methodist president and CEO Marc Boom in a statement.

NEW YORK STATE WILL START CORONAVIRUS DRUG TRIALS

"There is so much to be learned about this disease while it's occurring," Boom added. "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."

The hospital started recruiting donors from approximately 250 patients who have tested positive for COVID-19. Recruitment started as soon as the F.D.A. announced regulatory guidelines for the study last week, according to the statement.

“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 and principal investigator at the Methodist’s Research Institute, added in the statement. “We don’t have that much time.”

A second patient received a transfusion on Sunday, Salazar told the Chronicle, while adding it is "too early" to know if the transfusions are benefiting the patients.

Donating plasma is similar to donating blood, where donors are hooked up to a device that extracts the plasma and returns red blood cells into their bodies simultaneously. The process often takes about an hour and can be done more frequently than blood donations.

The news comes after a trial of five patients in China were aided in their recovery from COVID-19 to varying degrees. The patients, who were between the ages of 36 and 65, including two women, received an experimental plasma transfusion that contained a "neutralizing antibody," Fox News previously reported.

All five were on ventilators at the time of treatment and had previously received "antiviral agents and methylprednisolone."

After they received the plasma transfusion, four of the five patients had body temperatures return to normal "within three days," their Sequential Organ Failure Assessment (SOFA) score decreased and the ratio of arterial oxygen partial pressure to fractional inspired oxygen (also known as the PaO2/FiO2 ratio or Carrico index and the PF ratio) increased within 12 days.

Four of the five patients saw their acute respiratory issues resolve within 12 days after receiving the plasma transfusion and three of them were taken off ventilators within two weeks of treatment. Three patients were eventually discharged and the other two are in stable condition.

The study of the Chinese-based patients was published after New York State recently announced it too would attempt to fight the pandemic using the blood plasma of recovered patients.

CORONAVIRUS: COMBINATION OF ANTIMALARIAL MEDICATION AND ANTIBIOTICS COULD SHORTEN COVID-19, RESEARCHERS SAY

During a March 23 press conference, New York Gov. Andrew Cuomo said the blood therapy trial, which is aimed at coronavirus patients who are in the most serious condition, would start that week.

CLICK HERE FOR COMPLETE CORONAVIRUS COVERAGE

A Mount Sinai spokesperson told Fox News the hospital also initiated its convalescence plasma program on Saturday evening, "giving plasma to our first patient."

As of Monday afternoon, more than 745,000 coronavirus cases have been diagnosed worldwide, more than 144,000 of which are in the U.S.

CLICK HERE TO GET THE FOX NEWS APP

Fox News' James Rogers contributed to this story.