For days, Garcia’s mother, his aunt and his girlfriend have pleaded with doctors at Kaiser Permanente Downey Medical Center to try an experimental treatment — blood plasma from people recovered from COVID-19 — in hopes of saving his life.

They know it’s not at all a sure thing. But they’ve seen stories from across the country: an anesthesiologist in Colorado, an Orlando father of three, a dozen patients at a hospital in Texas, all of whom have received what’s known as convalescent plasma, an investigational therapy to halt the deadly virus. And they wonder why Garcia — the outgoing, ambitious father of a 9-year-old girl — can’t get it, too.

“Why not try it?” said Garcia’s mother, Irma Hoenes, 52. “What if it does help?”

So far, their efforts have been in vain. Hospital officials have declined to enroll Garcia in any clinical trial or expanded access program or to seek emergency individual use of convalescent plasma, though the federal Food and Drug Administration recently authorized these pathways for use in critically ill patients.

“The doctor just said no. His hospital is not participating in that treatment,” said Silvia Richard, Garcia’s aunt. “I don’t know how they can say they are trying everything.”

Garcia’s plight underscores the lack of coordination — and disparities in access — as families of failing COVID-19 patients jockey to obtain the still-unproven treatment. Even as efforts ramp up to collect blood plasma from the first survivors of the novel coronavirus, one’s chances of procuring the treatment appear to depend on accidents of geography, social-media savvy and the willingness of treating physicians.

“The demand is going to be super high, but I anticipate that it’s going to be a couple of weeks before we get anything like a pipeline to move from a trickle of product to a river,” said Dr. Michael Joyner, principal investigator of the Convalescent Plasma Expanded Access Program, coordinated by the Mayo Clinic.

“Disparities like this exist in our system — our non-system,” he said.

In the past two weeks, blood centers across the U.S. have accelerated efforts to collect COVID-19 convalescent plasma on the theory it contains protective antibodies that can transfer immunity from a patient who had the disease to someone still suffering.

The experimental practice was used during the devastating 1918 flu, as well as to treat measles in the 1930s. More recently, plasma therapy been used to treat victims of Ebola, SARS and H1N1 influenza. This year, an early review of five critically ill COVID-19 patients in China found that they appeared to improve after receiving convalescent plasma.

But the treatment is only now being studied in multiple clinical trials. FDA officials made clear that while the agency authorized the treatment for emergency use in serious or critically ill COVID-19 patients, much remains unknown. “Although promising, convalescent plasma has not yet been shown to be safe and effective as a treatment for COVID-19,” the agency wrote.

It remains uncertain, for instance, at what point in illness the therapy could be most helpful. Early research suggests that convalescent plasma may be most effective when given to people before they get sick or early in the course of the disease, said Arthur Caplan, director of the division of medical ethics at New York University School of Medicine.

But that doesn’t deter families desperate for a solution, he acknowledged. “I understand that you might want us to try anything and everything,” he said.

Fewer than 100 people so far have been treated with plasma through the emergency avenues approved by the FDA, according to the AABB, an international nonprofit focused on transfusion medicine and cellular therapies. The group has partnered with SurvivorCorps, a grassroots movement aimed at encouraging recovered COVID-19 patients to donate plasma.

So far, the use of COVID-19 plasma has been limited primarily by the number of eligible donors. “The biggest issue right now, the main, main issue right now, is just building up the supplies,” Joyner said.

Potential donors are people with lab-confirmed cases of COVID-19, who have recovered from, and since tested negative for, the virus. Blood centers anticipate it eventually will be possible to collect tens of thousands of units of COVID-19 convalescent plasma, said Eduardo Nunes, the AABB’s vice president of quality, transfusion and standards.

But, for now, supplies remain scarce. “This will only work if people come out and donate so that there is an inventory available,” said Dr. Alyssa Ziman, director of transfusion medicine at UCLA Health, where the blood center is beginning plasma collection this week.

The promise of plasma, set against the scarcity of supply, has led to families seeking out their own sources. Last week, the family of Dr. Priya Khanna, a New Jersey nephrologist, turned to Twitter after she was sickened with COVID-19.

“Plasma donor needed urgently for my beautiful young sister who dedicated her life to helping others,” read a wrenching April 8 tweet shared widely by health care workers. Within a day, Khanna’s family reported they had found a donor.

In Grapevine, Texas, Sue Szendrey began recruiting potential donors on Facebook after her husband, Billy Szendrey, 64, was hospitalized with COVID-19 on March 22. “We put out the word that we needed plasma,” she said. “I got 17 names over the weekend.”

One volunteer turned out to be eligible. The young woman donated her plasma at Carter BloodCare in Bedford, Texas, one of the centers collecting plasma. Dr. Geeta Paranjape, the center’s medical director, said the plasma was reserved for Baylor Scott & White Medical Center Grapevine, where Billy Szendrey is being treated.

“We rely on the physician to use it in the best possible way,” Paranjape said.

On April 9, Billy Szendrey received the plasma, much to his wife’s relief. “Don’t you want to give people a chance?” Sue Szendrey said. “If you can get this done, do it.”

Back in L.A., Stephen Garcia’s family said he is being denied that chance and with little explanation.

Garcia’s mother said she repeatedly has asked her son’s physicians about obtaining convalescent plasma. They “just said there’s not a lot of information and they’re not participating,” she said.

In an email, Kaiser Permanente spokesman Marc Brown said that hospital officials are committed to providing “state-of-the-art care for patients with COVID-19” but that they couldn’t comment on a specific patient.

Brown did not make Garcia’s physicians available for an interview. Kaiser Health News reached out directly to one of the physicians, Dr. Timothy Hulbert, a critical care specialist, who did not respond to a request for comment. (Kaiser Health News is not affiliated with Kaiser Permanente.)

Brown did not address questions about whether the hospital system would provide convalescent plasma to any patient, not just Garcia.

“Individual treatment decisions, including the compassionate use of potential therapies outside of the context of a clinical trial, are made between the patient and their physicians based on both the risks and the potential benefits in a particular clinical situation,” Brown’s email said.

Hospital systems aren’t required — legally or ethically — to provide access to unproven treatments, said Caplan, the bioethics professor.

“If the physician believes that there’s no point, given prior use and the resources diversion that it might take to do it, you can’t do it without the physician being on board,” Caplan said.

There’s no denying that some patients will have access to convalescent plasma and others won’t, Joyner said. “Many of these decisions will be made at the level of individual providers or groups of providers,” he said.

Even when patients do obtain plasma, there’s no guarantee it will help. Despite the Texas donor’s efforts, Billy Szendrey remained unconscious, in critical condition, several days after the treatment, his wife said. In New Jersey, Dr. Priya Khanna died early Monday, her family reported on Twitter. She was 43.

The sad truth is it’s not yet clear how best to treat COVID-19 patients, especially those who require ventilators, said Joyner, an anesthesiologist. A dose of antibody-rich plasma remains promising, but not certain.

“The idea that a single intervention is going to have a Lazarus-like effect? It’s possible, but it’s very unusual,” Joyner said. “It’s a very difficult proposition to turn those people around.”