Craige Campbell, a site manager from Desert Hot Springs, Calif., began messaging his doctor immediately after testing positive for COVID-19 and developing a 101-degree fever. Despite having no underlying medical conditions, he will soon be able to get a prescription.

The only pharmacy that dispenses medicines is more than an hour’s drive away, so Campbell asked a friend to fetch it for him.

“I feel a little privileged in a way,” he said. “There’s a very good chance it’ll land on my plate in the right amount of time.”

At the same time, there is a shortage of antibody drugs, infusions or injections that can prevent deaths and hospitalizations. Only one of them is from GlaxoSmithKline and seems to work for omicron, and it’s also being rationed.

Federal officials have limited its shipments to about 50,000 doses per week. This week, the government announced the purchase of an additional 600,000 doses on top of the 400,000 doses purchased in November.

At Pennsylvania’s UPMC hospital system, staff can treat fewer than 1,000 patients a week with antibodies, down from 4,000 patients early in the pandemic.

Doctors and nurses across the U.S. have developed sophisticated ways to decide who should get scarce medicines based on patients’ symptoms, potential medical risks, where they live and whether they are healthy enough to travel for infusions.

“What do we have at hand?” is the first question, says Dr. Greg Schrank of the University of Maryland Medical Center. “Of these therapies, what is the most effective, and how do we direct it to those who we know are at greatest risk?”

The increasingly complex treatment situation comes as exhausted and frustrated hospital staff try to manage rising admissions numbers.

As of Sunday, nearly 128,000 Americans were hospitalized with COVID-19, surpassing the all-time high of about 125,000 in January last year. While fewer COVID-19 patients are now requiring intensive care, the surge is pushing hospitals to a tipping point.

Given the threat, Pfizer’s pill arrived just in time, Schrank said.

“It’s not going to reverse the trend in the total number of cases, but it does help mitigate the impact on hospitals,” he said.