A nurse enters a monoclonal antibody site, Wednesday, Aug. 18, 2021, at C.B. Smith Park in Pembroke Pines, Florida. Credit: Marta Lavandier / AP

One of the most effective treatments for COVID-19 is in short supply at hospitals in Maine and nationally and the rise of the omicron variant will create new problems.

Monoclonal antibodies, which are made in a laboratory and given as infusions to older and high-risk people who have tested positive for the virus or been exposed to it, have emerged as the key tool for preventing COVID-19 deaths after cases are detected.

But scientists believe that only one of the three monoclonal antibody treatments approved by the U.S. Food and Drug Administration — sotrovimab — effectively fights the infection in omicron patients. Supplies are now stretched, including in New York City, where three hospital networks told The New York Times they had run out by this week.

Maine does not currently have enough sotrovimab to treat scores of new omicron patients, Maine Center for Disease Control and Prevention Director Nirav Shah said Wednesday. In response, providers will likely restrict treatments to only the most at-risk patients, according to hospitals and epidemiologists.

“I wish as a country we had more sotrovimab, because if the country did, then Maine would,” Shah said.

The omicron variant was first detected in Maine last week as hospitals around the state were still contending with the effects of a surge in delta variant cases that has hammered hospitals and strained health care resources. The U.S. CDC has already said omicron is the dominant strain nationally and Maine health officials expect it to overtake the delta variant here within weeks.

It appears that conventional COVID treatments, including vaccinations, are less effective against the omicron variant, though they are still expected to fend off serious illness. Preliminary studies also show omicron may be more contagious than previous strains but produces less severe symptoms.

The lack of effectiveness of the other two other antibody treatments is the primary way that treating omicron patients differs from those infected with the delta variant, Dr. James Jarvis, who helps run Brewer-based Northern Light Health’s COVID-19 response, said Wednesday.

“Since we’re mostly dealing with delta at this point, we can use the other two monoclonal antibodies in order to treat patients,” Jarvis said. “But we know that’s going to be a matter of time before that shifts and changes.”

Maine receives a certain share of monoclonal antibodies from the federal government. Those determinations are based on factors such as population and infection rates. The administration of President Joe Biden initially paused every-other-week shipments last month to conserve sotrovimab supply.

The U.S. Department of Health and Human Services has shipped some 55,000 doses to states and plans to increase its supply in January. Maine will receive 414 doses of sotrovimab from that Dec. 17 shipment, according to federal data.

As supplies shorten, it is more important to prioritize treatment for vulnerable patients, including those with conditions like chronic kidney disease, lung disease and Type-2 diabetes, or who are pregnant or obese, said Dr. Peter Millard, a former U.S. CDC epidemiologist who now teaches at the University of New England.

Delta is still likely the dominant strain in Maine, noted John Porter, a spokesperson for MaineHealth. The state’s largest health provider, which runs Maine Medical Center in Portland, intends to prioritize sotrovimab for its most at-risk patients if and when omicron pulls ahead of delta, he said.

“It’s not unprecedented,” Porter said. “We’ve done that earlier on when supplies were tight for other types of antibody treatments.”

Wednesday did bring good news that could bolster providers’ arsenal against COVID. The FDA approved Paxlovid, an antiviral Pfizer pill that can be taken at home, and is expected to soon authorize another medication from Merck.

Antiviral medications would be a “gamechanger” for treating unvaccinated people and lessening chances of death, Millard said. But approval doesn’t mean the medication will be easily available, cautioned Dr. Robert Horsburgh, a Boston University epidemiologist.

“It’s one thing for the FDA to approve it,” Horsburgh said. “It’s another thing for the companies to make enough of it and ship it to the hospital. It’s a logistical issue, not a medical issue.”

Porter said that the government told providers around the country that there were 265,000 initial doses of the antiviral medication available between now and the end of January. MaineHealth expects to receive “a little less than a thousand” of those doses in the next few months, he said.

“The month following this could be a very significant step forward in the fight to get COVID under control,” Porter said.

Lia Russell

Lia Russell is a reporter on the city desk for the Bangor Daily News. Send tips to LRussell@bangordailynews.com.