Minnesota is beginning to receive limited supplies of a new COVID-19 therapy that could reduce the need for hospital stays and trips to the emergency room — a tantalizing promise as medical centers struggle with a surge of patients while the pandemic virus sidelines more health care workers.

The treatment is a "monoclonal antibody" therapy similar to the one received by President Donald Trump after he was sickened this fall with COVID-19, but is made by a different company for patients who haven't been hospitalized and don't require oxygen therapy. Last month, the federal government announced the purchase of 300,000 doses of the treatment, saying it would help bridge the gap before coronavirus vaccines become available.

Yet for all the treatment's promise, it creates a logistical challenge, doctors say, because it must be infused for about an hour at centers without creating risks for other patients. Plus, the doses available likely will be dwarfed by the number of patients who could potentially benefit, at least initially.

"As a therapeutic agent, the data supports that it likely does really reduce the occurrence of serious illness," said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "The challenge we have is … who do you give it to first?"

The Minnesota Department of Health announced Tuesday that the federal government has begun distribution of the new treatment, which is called bamlanivimab and is meant for people with mild and moderate cases of COVID-19.

An initial shipment is expected to bring about 2,400 doses to Minnesota, the state said. Federal officials said weekly allocations will be proportionally based on confirmed COVID-19 cases in each state and territory over the previous seven days.

Manufactured by Eli Lilly, the Indiana-based pharmaceutical giant, the treatment received emergency use authorization from the Food and Drug Administration on Nov. 9. It's a time-sensitive therapy, the Health Department said, and must be given as soon as possible after a positive result and within 10 days of developing symptoms.

"To be able to use this treatment, people should get tested as soon as possible if they become ill and reach out to their health care provider quickly if they receive a positive test," Dr. Ruth Lynfield, state epidemiologist and medical director for the Minnesota Department of Health, said in a statement. "Supplies will be limited at this point, but this therapy provides an additional option to help limit the impacts of this serious disease."

Due to the supply limits, the Health Department says it's been working with medical ethicists to develop a framework for deciding which patients should get the treatment. Only children and adults who are at high risk for severe disease will be eligible, the state said, adding that those patients were highlighted as potential candidates by federal regulators.

Dr. Mark McClellan, a health policy expert at Duke University, called the treatment "very promising" during a call with reporters Tuesday, but stressed the logistical challenges that come with it.

Monoclonal antibodies are laboratory-made proteins that are meant to work like the antibodies that patients would develop after receiving a vaccine against COVID-19, McClellan said.

Studies are finding that the antibody treatment developed by Eli Lilly can neutralize the coronavirus for people who are treated early, and thereby prevent serious complications and hospitalizations.

But a Duke research paper released this week estimated the treatment's supply of 150,000 doses per month would be exhausted within just four days, based on the current COVID-19 surge. The more immediate challenge is that health care providers must create a system for safely delivering the medication, which takes an hourlong infusion, said McClellan, who was a top health official in the administration of President George W. Bush.

"You can't put patients who are getting infused for COVID, who are actively infectious, in the same place as a cancer patient or other people who benefit from monoclonal antibody infusions — it's got to be a separate approach," he said. "I do worry about the supply we have, but right now we're not there yet on taking advantage of this treatment."

The Mayo Clinic is moving quickly to create a structure for safely providing the new treatment, said Dr. Andrew Badley, chairman of the COVID Research Task Force at the Rochester-based clinic. The plan includes an infusion center in Rochester and four other locations across southeastern Minnesota.

A large study showed that outpatients who were newly diagnosed with COVID-19 and received the therapy within 10 days ran a significantly lower risk of being hospitalized or going to an emergency room, Badley said. Whereas 6.3% of patients in the study who did not receive treatment needed hospital or ER care, and that was true for only 1.6% of patients who received the antibody.

The impact was even greater for people age 65 and older, Badley said, as well as those with moderate- and high-risk obesity. The results suggest the treatment is a "positive step," he said, in treating coronavirus infection and lessening the overall burden created by COVID-19.

"It is possible, if not probable, that there will be demand exceeding supply in the early days," Badley said. But he added: "We fully expect that there will be other monoclonal antibody [emergency approvals] soon."

Side effects in clinical studies have included nausea, diarrhea, dizziness, headache, itching and vomiting in between 2% and 4% of people, the Health Department says. Serious reactions such as allergic reactions or infusion reactions have occurred, the Health Department said, but are uncommon. Studies are ongoing, so not all side effects may be known at this time.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck